Bruce
03-18-2004, 05:35 PM
Submitted by Doug Martin,
CALPACK-Part Number-16036503,
AC Delco Number-Same
Diagnostic Alarm Code-52 CALPACK Error
Location-The CALPACK is the small computer chip located under the PROM access cover in the ECM.
Purpose-The CALPACK contains the limp home program information.
How It Works-If there is damage to the ECM or the PROM chip the computer will use the information contained in the CALPACK limp home program.
Cam Position Sensor-Part number-25518357
With drive-Part number-25516915, AC Delco number-213-143
Location-The cam position sensor is located on the top of the water pump cover, where the distributor would normally sit.
Diagnostic Alarm Codes- 41 cam sensor circuit failure
Purpose-The cam position sensor (cam sensor) lets the ECM know where #6 cylinder is in the firing order.
How It Works-The cam sensor uses a Hall Effect system. This system uses an interrupter ring and a magnetic pick up. The interrupter ring is bolted on to the top of the cam sensor shaft. The other end is connected to the camshaft and has one window notched out of its circumference. When the window passes through the magnetic pick up in the cap, the ECM knows where to begin the fuel injector sequence.
Quick Check- Disconnect the cam sensor wiring connector AFTER the car is started. Then take the car for a quick spin around the block. If your problem disappears after taking a ride your cam sensor has a problem. The cam sensor must be reconnected car or the car will not restart.
Specialty Tools-Caspers Electronics makes a Cam Tool (part number 102075) that has became a standard for setting the timing of the cam sensor.
Torque- The torque for the cam sensor hold down clamp is 20 ft-lbs.
Website-Caspers Electronics - Quality Engineered Electronic Performance Items
Coolant Temperature Sensor- Part number-3053190,
AC-Delco number-213-928
Diagnostic Alarm Code-coolant temperature sensor circuit (High Temp)
coolant temperature sensor circuit (Low Temp)
Location-The engine coolant sensor is located on the right front of the intake manifold under the fuel pressure regulator.
Purpose-This sensor tells the ECM what the coolant temperature of the engine is.
How it works-The coolant temperature sensor is a thermister that reads the coolant temperature. The ECM will send a 5 volt reference signal to the coolant temperature sensor. As the coolant temperature rises the sensor will offer less resistance allowing more volts to pass through to the ECM.
Coolant Temperature Switch-Part number-25036371,
AC Delco number-D1896
Location-The coolant temperature sensor is located on the front of the passenger’s side of the intake manifold.
Purpose-The coolant temperature sensor will signal the coolant idiot light in the dash if the car starts to overheat.
How It Works- The coolant temperature sensor will signal the idiot light in the dash when the coolant temperature rises to 257˚.
Crank Sensor-Part number-12537109, AC Delco Part number-213-292
Bracket-Part number-12537113,
AC Delco Part number-213-280
Complete-Part number-25525667
Location-The crank sensor is located on the driver’s side behind the harmonic balancer.
Purpose-The crank sensor lets the ECM know when the pistons are at top dead center.
How It Works-The crank sensor uses a Hall Effect system. This system uses an interrupter ring and a magnetic pick up. The interrupter ring is connected to the back of the harmonic balancer and has 3 windows notched out of its circumference. When these windows pass over the magnetic pick up the ECM knows that the piston is at top dead center.
Torque-The torque on the two bolts holding the crank sensor bracket is 22 ft-lbs. The pinch bolt (AC Delco number 213-281) is 30 *in-lbs*.
Electronic Control Module-Part number-1227148
Diagnostic Alarm Code-55 electronic control module error
Location-The electronic control module (ECM) is located behind the passenger’s side kick panel.
Purpose-The ECM is controlled by the PROM chip
How It Works-The ECM executes the information stored in the PROM chip. The ECM has the ability to learn, it can self diagnose (check engine light) the engine electrical system for any malfunctioning sensors. The ECM will then store the alarm codes and other changes that are made to the car’s engine electrical system. If the battery is disconnected it will loose all of the codes and memory. It will take a while for the ECM to learn all of the info again. Also the ECM uses the MAF and the O2 sensor to maintain a constant 14.7:1 air/fuel ratio.
Electronic Spark Control- 1986 Part number-16022614,
1987 Part number-16051654
1986 AC Delco number-216-33,
1987 AC Delco number-216-42
Diagnostic Alarm Code-43 electronic spark control (ESC) failure
Location-The ESC is located on the passenger’s inner fender.
Purpose-The ESC detects detonation and will retard the timing as needed.
How It Works-The ESC works in conjunction with the knock sensor. The knock sensor picks up frequencies and sends the information to the ESC. The ESC filters out all the unneeded frequencies. It looks for the frequencies associated with detonation. It will analyze the information and retard the timing accordingly. The ESC can retard the timing up to 20° in 1° increments.
Electronic Vacuum Regulator Valve-Part number-25527186
(Exhaust Gas Recirculation solenoid)
AC Delco Part number-214-307
Diagnostic Alarm Code-32 exhaust gas recirculation (EGR) Circuit
Location-The electronic vacuum regulator valve (EVRV) is located on top of the driver’s side intake manifold.
Purpose-The EVRV controls opening and closing EGR valve.
How It Works-The EVRV uses engine vacuum to determine when the EGR valve should be opened or closed. The EGR valve is only used when cruising down the road. At idle or wide open throttle the valve will be closed.
Maintenance- There is a filter located at the back of the valve. The filter should be inspected and replaced periodically.
Idle Air Control valve-Part number-25527077,
AC Delco Part number-217-437
Location-The idle air control valve (IAC) is located on the front of the throttle body. It is below the up pipe from the intercooler.
Purpose-The IACs main function is to control the idle quality.
How it works-It controls the idle with a motor driven plunger. As the air enters the throttle body the throttle blade is basically closed. The air will then enter a hole in front of the throttle blade. Then the air will go through a tapered hole. This is where the IAC plunger is located. It will extend or retract the plunger as needed to maintain the idle. Then the air will exit on the backside of the throttle blade. At an idle the IAC should read somewhere in between 15-20. This may not on be true for all cars, sometimes the number may be higher.
Alternatives-Sometimes if a large MAF pipe is used it will compete for the same space as the IAC. BOP Engineering and Champion Racing Heads both sell a product to solve this problem. Both turn the IAC on a 45-degree angle towards the alternator.
Websites- http://www.bopengineering.com/buick_v6.shtml
http://www.championracingheads.com/gn1/products_valveadapter.html
Ignition Module-Part number-25527221, AC Delco number-D1996
Diagnostic Alarm Code-42 C3I electronic spark timing (EST) failure
Location-The ignition module is located at the back of intake manifold under the coil pack.
Purpose-The ignition module controls the ignition coil pack.
How it works-The ignition module contains the primary circuits that turn the individual coils on and off. The module also controls all ignition function under 400 RPM.
Ignition Coil Pack-Part number-25533542,
AC Delco number-D552
Location-The ignition coil pack is located at the back of intake manifold on top of the ignition module.
Purpose-To deliver spark to the cylinders.
How it works-The coil pack receives a signal from the ignition module. Then it sends spark to both the cylinder and the waste spark cylinder.
Quick Check-An ohm test can determine if your coil pack is starting to malfunction. The individual towers should ohm 11k-13k, the lower the better. This is not a conclusive test. The coil pack still may be bad. The only way to check it correctly is with a CCCI Ignition Tester from Caspers Electronics.
Websites- http://www.casperselectronics.com
Knock Sensor-Part number-10456287,
AC Delco Part number-213-325
Location-The knock sensor is located on the driver’s side block above the bell housing.
Purpose-The knock sensor tells the ECM if there is any detonation occurring in the engine.
How it works-It is basically an electronic microphone. It picks up frequencies and sends them to the ESC.
Torque-14 ft-lbs
Manifold air temperature sensor-Part number-
AC Delco number-213-190
Location-The manifold air temperature sensor (MAT) is located on the elbow between the MAF and the air cleaner. If a aftermarket air filter is used it normally is located beside the hose clamp.
Diagnostic alarm code-25 manifold air temperature circuit (high temp)
Purpose-The MAT relays the temperature of the incoming air to the ECM.
How it works-The ECM sensor sends out a 5 volt reference signal to the MAT sensor. The ECM will then read the resistance it receives from the MAT. If the temperature is low it will have a high reading. If the temperature is high it will receive low reading.
Mass air flow sensor- Part number-25007866 (Discontinued)
Location-The mass air flow (MAF) is located between the alternator and the radiator. One end of the MAF connects to the air filter and the other end connects to a hose/tubing that is connected to the turbocharger.
Diagnostic alarm codes- 33 MAF circuit (high)
34 MAF circuit (low or no signal)
Purpose-The MAF tells the ECM how much air the engine is using.
How it works-The MAF has a heated film that sits in the air stream. As the air passes over the film the temperature will drop. A resistor measures the temperature of the film and sends the information to the ECM.
Alternatives-The stock MAF sensors are not manufactured by GM. Some people have some luck with aftermarket rebuilt units. It seems that there is a 50% chance of the aftermarket MAF will work. Another alternative is buying a Translator. A Translator will allow you to run a later model style MAF. The most common MAFs used with the Translator is a 3” LT1 (part # 25180303), a 3.5” LS1 (part # 25179711), or a 3 5/8 Z06 (part # 25168491). Caspers Electronics sells a harness that adapts the 5 pin LS1 and Z06 MAF connector to a LT1 3 pin. This harness also integrates the air temperature sensor. This way you don’t have to run an external air temperature sensor. It is incorporated into the LS1 and Z06 MAF sensors. Full Throttle Speed & Style also sells a Translator Plus. The Plus has all of the features of the Translator. But it also let the owner adjust the ignition timing. There is also an option with the Translator that lets you double the air flow grams that the ECM sees. You have to get the Extender chip to use this option. Another alternative is a MaxEffort Digital Fuel Management system. They make a racing version of the system called ME-R. It does not use a MAF at all.
Websites-Translator-Full Throttle Speed & Style Web Site- Store Front Page
Harness-Caspers Electronics - Quality Engineered Electronic Performance Items
Maxeffort-MAXEFFORT Digital Programmable Fuel Management
Throttle Position Sensor-Part number-25036663,
AC Delco Part number-213-918
Location-The throttle position sensor (TPS) is located on the passenger side of the throttle body.
Diagnostic alarm codes-21 TPS circuit (high)
22 TPS circuit (low)
Purpose-The TPS lets the ECM know what position the throttle shaft is located.
How it works-The ECM will send out a 5-volt reference signal. Once the ECM receives a .40-.44 volt from the TPS it knows it is at an idle. The standard setting for full throttle has always been 4.5 volts. However the ECM sees 75% of the 5 volts (3.75 volts) it will invoke power enrichment mode. The ECM has to see 4 volts to turn off the Air Conditioning. Steve Wood has a very good explanation that is a lot more in depth on his website Vortex Buicks.
Website- Vortex Turbo Buick Performance
Oxygen Sensor-Stock part number-25162693,
GNX part number-25162753
AC Delco number-213-503,
AC Delco GNX-213-504
Diagnostic alarm code-13 oxygen sensor circuit open
Location-The oxygen sensor (O2 sensor) is located on the passengers side exhaust manifold under the turbocharger.
Purpose-The O2 sensor tells the ECM if the engine is running rich or lean.
How it works-It does not make a good tuning device. If the O2 sensor sees that the air/fuel ratio is higher the 14.7, it will lean out the motor. If the O2 sensor sees that the air/fuel ratio is less than 14.7, it will give the engine more fuel.
Alternatives-For many years a lot of people changed from the stock 1 wire O2 sensor to a 4 wire heated O2 sensor. Caspers Electronics sells a plug and play wiring kit for a heated sensor. Using leaded racing fuels was one of the main reasons this was done. Denso (part number 234 0001) has come up with a new O2 sensor that is more tolerant of racing fuels. It seems to last longer than stock and heated O2 sensors. However in time the lead will clog up the sensor. Another alternative is a MaxEffort Digital Fuel Management system. It uses a thumbwheel to program the chip. MaxEffort keeps the ECM in an open loop, so an O2 sensor is not needed.
Website-MAXEFFORT Digital Programmable Fuel Management
PROM Chip-Part number-16051877,
California number-16036503
Diagnostic alarm code-51 PROM error
Location-The programmed read only memory (PROM) chip is the big computer chip located under the PROM access cover in the ECM.
Purpose-The PROM chip tells the ECM what to do.
How It Works-All of the fuel codes, ignition curves, TCC, etc are stored in the Prom chip. This is read only information, the ECM can not rewrite any of the information..
Torque Converter Clutch Solenoid-Part number-8639900
Location-You must remove the transmission pan. The TCC is located in the front of the transmission right behind the pan rail. Just follow the wires.
Purpose-The TCC sends the signal to lock the torque converter in overdrive.
How It Works- When signaled by the ECM the TCC will move the lock-up valve in the transmission. This will reverse the flow of transmission fluid and create pressure to lock the torque converter clutch up
Vehicle Speed Sensor-Part number-25007463,
AC Delco number-213-110
Diagnostic alarm code-24 vehicle speed sensor circuit failed
Location- There is two parts of a vehicle speed sensor (VSS). The first part is the reader, it is attached to the back of the speedometer. The second part is behind the stereo and heater controls. They are connected with a ribbon of three wires.
How it works-The VSS has a reader that is connected to the back of the speedometer. There are two reflective tabs on the back of the speedometer that the reader will count. Every turn of the speedometer cable results in two pulses. There are 2000 pulses in a mile. The reader will send the pulses to the module. The module will then decipher the pulses and send the information to the ECM. It is also used for cruise control.
Wastegate Solenoid-Part number-1997157,
AC Delco Part number-214-609
Location-The wastegate solenoid is located on the top of the passenger valve cover. It uses a red connector.
Diagnostic alarm code-31 wastegate solenoid electrical signal failed.
Purpose-The wastegate solenoid is how the ECM controls boost.
How it works-It is an electronic bleeder that uses pulses to release boost into the atmosphere if detonation is detected.
Doug Martin
CALPACK-Part Number-16036503,
AC Delco Number-Same
Diagnostic Alarm Code-52 CALPACK Error
Location-The CALPACK is the small computer chip located under the PROM access cover in the ECM.
Purpose-The CALPACK contains the limp home program information.
How It Works-If there is damage to the ECM or the PROM chip the computer will use the information contained in the CALPACK limp home program.
Cam Position Sensor-Part number-25518357
With drive-Part number-25516915, AC Delco number-213-143
Location-The cam position sensor is located on the top of the water pump cover, where the distributor would normally sit.
Diagnostic Alarm Codes- 41 cam sensor circuit failure
Purpose-The cam position sensor (cam sensor) lets the ECM know where #6 cylinder is in the firing order.
How It Works-The cam sensor uses a Hall Effect system. This system uses an interrupter ring and a magnetic pick up. The interrupter ring is bolted on to the top of the cam sensor shaft. The other end is connected to the camshaft and has one window notched out of its circumference. When the window passes through the magnetic pick up in the cap, the ECM knows where to begin the fuel injector sequence.
Quick Check- Disconnect the cam sensor wiring connector AFTER the car is started. Then take the car for a quick spin around the block. If your problem disappears after taking a ride your cam sensor has a problem. The cam sensor must be reconnected car or the car will not restart.
Specialty Tools-Caspers Electronics makes a Cam Tool (part number 102075) that has became a standard for setting the timing of the cam sensor.
Torque- The torque for the cam sensor hold down clamp is 20 ft-lbs.
Website-Caspers Electronics - Quality Engineered Electronic Performance Items
Coolant Temperature Sensor- Part number-3053190,
AC-Delco number-213-928
Diagnostic Alarm Code-coolant temperature sensor circuit (High Temp)
coolant temperature sensor circuit (Low Temp)
Location-The engine coolant sensor is located on the right front of the intake manifold under the fuel pressure regulator.
Purpose-This sensor tells the ECM what the coolant temperature of the engine is.
How it works-The coolant temperature sensor is a thermister that reads the coolant temperature. The ECM will send a 5 volt reference signal to the coolant temperature sensor. As the coolant temperature rises the sensor will offer less resistance allowing more volts to pass through to the ECM.
Coolant Temperature Switch-Part number-25036371,
AC Delco number-D1896
Location-The coolant temperature sensor is located on the front of the passenger’s side of the intake manifold.
Purpose-The coolant temperature sensor will signal the coolant idiot light in the dash if the car starts to overheat.
How It Works- The coolant temperature sensor will signal the idiot light in the dash when the coolant temperature rises to 257˚.
Crank Sensor-Part number-12537109, AC Delco Part number-213-292
Bracket-Part number-12537113,
AC Delco Part number-213-280
Complete-Part number-25525667
Location-The crank sensor is located on the driver’s side behind the harmonic balancer.
Purpose-The crank sensor lets the ECM know when the pistons are at top dead center.
How It Works-The crank sensor uses a Hall Effect system. This system uses an interrupter ring and a magnetic pick up. The interrupter ring is connected to the back of the harmonic balancer and has 3 windows notched out of its circumference. When these windows pass over the magnetic pick up the ECM knows that the piston is at top dead center.
Torque-The torque on the two bolts holding the crank sensor bracket is 22 ft-lbs. The pinch bolt (AC Delco number 213-281) is 30 *in-lbs*.
Electronic Control Module-Part number-1227148
Diagnostic Alarm Code-55 electronic control module error
Location-The electronic control module (ECM) is located behind the passenger’s side kick panel.
Purpose-The ECM is controlled by the PROM chip
How It Works-The ECM executes the information stored in the PROM chip. The ECM has the ability to learn, it can self diagnose (check engine light) the engine electrical system for any malfunctioning sensors. The ECM will then store the alarm codes and other changes that are made to the car’s engine electrical system. If the battery is disconnected it will loose all of the codes and memory. It will take a while for the ECM to learn all of the info again. Also the ECM uses the MAF and the O2 sensor to maintain a constant 14.7:1 air/fuel ratio.
Electronic Spark Control- 1986 Part number-16022614,
1987 Part number-16051654
1986 AC Delco number-216-33,
1987 AC Delco number-216-42
Diagnostic Alarm Code-43 electronic spark control (ESC) failure
Location-The ESC is located on the passenger’s inner fender.
Purpose-The ESC detects detonation and will retard the timing as needed.
How It Works-The ESC works in conjunction with the knock sensor. The knock sensor picks up frequencies and sends the information to the ESC. The ESC filters out all the unneeded frequencies. It looks for the frequencies associated with detonation. It will analyze the information and retard the timing accordingly. The ESC can retard the timing up to 20° in 1° increments.
Electronic Vacuum Regulator Valve-Part number-25527186
(Exhaust Gas Recirculation solenoid)
AC Delco Part number-214-307
Diagnostic Alarm Code-32 exhaust gas recirculation (EGR) Circuit
Location-The electronic vacuum regulator valve (EVRV) is located on top of the driver’s side intake manifold.
Purpose-The EVRV controls opening and closing EGR valve.
How It Works-The EVRV uses engine vacuum to determine when the EGR valve should be opened or closed. The EGR valve is only used when cruising down the road. At idle or wide open throttle the valve will be closed.
Maintenance- There is a filter located at the back of the valve. The filter should be inspected and replaced periodically.
Idle Air Control valve-Part number-25527077,
AC Delco Part number-217-437
Location-The idle air control valve (IAC) is located on the front of the throttle body. It is below the up pipe from the intercooler.
Purpose-The IACs main function is to control the idle quality.
How it works-It controls the idle with a motor driven plunger. As the air enters the throttle body the throttle blade is basically closed. The air will then enter a hole in front of the throttle blade. Then the air will go through a tapered hole. This is where the IAC plunger is located. It will extend or retract the plunger as needed to maintain the idle. Then the air will exit on the backside of the throttle blade. At an idle the IAC should read somewhere in between 15-20. This may not on be true for all cars, sometimes the number may be higher.
Alternatives-Sometimes if a large MAF pipe is used it will compete for the same space as the IAC. BOP Engineering and Champion Racing Heads both sell a product to solve this problem. Both turn the IAC on a 45-degree angle towards the alternator.
Websites- http://www.bopengineering.com/buick_v6.shtml
http://www.championracingheads.com/gn1/products_valveadapter.html
Ignition Module-Part number-25527221, AC Delco number-D1996
Diagnostic Alarm Code-42 C3I electronic spark timing (EST) failure
Location-The ignition module is located at the back of intake manifold under the coil pack.
Purpose-The ignition module controls the ignition coil pack.
How it works-The ignition module contains the primary circuits that turn the individual coils on and off. The module also controls all ignition function under 400 RPM.
Ignition Coil Pack-Part number-25533542,
AC Delco number-D552
Location-The ignition coil pack is located at the back of intake manifold on top of the ignition module.
Purpose-To deliver spark to the cylinders.
How it works-The coil pack receives a signal from the ignition module. Then it sends spark to both the cylinder and the waste spark cylinder.
Quick Check-An ohm test can determine if your coil pack is starting to malfunction. The individual towers should ohm 11k-13k, the lower the better. This is not a conclusive test. The coil pack still may be bad. The only way to check it correctly is with a CCCI Ignition Tester from Caspers Electronics.
Websites- http://www.casperselectronics.com
Knock Sensor-Part number-10456287,
AC Delco Part number-213-325
Location-The knock sensor is located on the driver’s side block above the bell housing.
Purpose-The knock sensor tells the ECM if there is any detonation occurring in the engine.
How it works-It is basically an electronic microphone. It picks up frequencies and sends them to the ESC.
Torque-14 ft-lbs
Manifold air temperature sensor-Part number-
AC Delco number-213-190
Location-The manifold air temperature sensor (MAT) is located on the elbow between the MAF and the air cleaner. If a aftermarket air filter is used it normally is located beside the hose clamp.
Diagnostic alarm code-25 manifold air temperature circuit (high temp)
Purpose-The MAT relays the temperature of the incoming air to the ECM.
How it works-The ECM sensor sends out a 5 volt reference signal to the MAT sensor. The ECM will then read the resistance it receives from the MAT. If the temperature is low it will have a high reading. If the temperature is high it will receive low reading.
Mass air flow sensor- Part number-25007866 (Discontinued)
Location-The mass air flow (MAF) is located between the alternator and the radiator. One end of the MAF connects to the air filter and the other end connects to a hose/tubing that is connected to the turbocharger.
Diagnostic alarm codes- 33 MAF circuit (high)
34 MAF circuit (low or no signal)
Purpose-The MAF tells the ECM how much air the engine is using.
How it works-The MAF has a heated film that sits in the air stream. As the air passes over the film the temperature will drop. A resistor measures the temperature of the film and sends the information to the ECM.
Alternatives-The stock MAF sensors are not manufactured by GM. Some people have some luck with aftermarket rebuilt units. It seems that there is a 50% chance of the aftermarket MAF will work. Another alternative is buying a Translator. A Translator will allow you to run a later model style MAF. The most common MAFs used with the Translator is a 3” LT1 (part # 25180303), a 3.5” LS1 (part # 25179711), or a 3 5/8 Z06 (part # 25168491). Caspers Electronics sells a harness that adapts the 5 pin LS1 and Z06 MAF connector to a LT1 3 pin. This harness also integrates the air temperature sensor. This way you don’t have to run an external air temperature sensor. It is incorporated into the LS1 and Z06 MAF sensors. Full Throttle Speed & Style also sells a Translator Plus. The Plus has all of the features of the Translator. But it also let the owner adjust the ignition timing. There is also an option with the Translator that lets you double the air flow grams that the ECM sees. You have to get the Extender chip to use this option. Another alternative is a MaxEffort Digital Fuel Management system. They make a racing version of the system called ME-R. It does not use a MAF at all.
Websites-Translator-Full Throttle Speed & Style Web Site- Store Front Page
Harness-Caspers Electronics - Quality Engineered Electronic Performance Items
Maxeffort-MAXEFFORT Digital Programmable Fuel Management
Throttle Position Sensor-Part number-25036663,
AC Delco Part number-213-918
Location-The throttle position sensor (TPS) is located on the passenger side of the throttle body.
Diagnostic alarm codes-21 TPS circuit (high)
22 TPS circuit (low)
Purpose-The TPS lets the ECM know what position the throttle shaft is located.
How it works-The ECM will send out a 5-volt reference signal. Once the ECM receives a .40-.44 volt from the TPS it knows it is at an idle. The standard setting for full throttle has always been 4.5 volts. However the ECM sees 75% of the 5 volts (3.75 volts) it will invoke power enrichment mode. The ECM has to see 4 volts to turn off the Air Conditioning. Steve Wood has a very good explanation that is a lot more in depth on his website Vortex Buicks.
Website- Vortex Turbo Buick Performance
Oxygen Sensor-Stock part number-25162693,
GNX part number-25162753
AC Delco number-213-503,
AC Delco GNX-213-504
Diagnostic alarm code-13 oxygen sensor circuit open
Location-The oxygen sensor (O2 sensor) is located on the passengers side exhaust manifold under the turbocharger.
Purpose-The O2 sensor tells the ECM if the engine is running rich or lean.
How it works-It does not make a good tuning device. If the O2 sensor sees that the air/fuel ratio is higher the 14.7, it will lean out the motor. If the O2 sensor sees that the air/fuel ratio is less than 14.7, it will give the engine more fuel.
Alternatives-For many years a lot of people changed from the stock 1 wire O2 sensor to a 4 wire heated O2 sensor. Caspers Electronics sells a plug and play wiring kit for a heated sensor. Using leaded racing fuels was one of the main reasons this was done. Denso (part number 234 0001) has come up with a new O2 sensor that is more tolerant of racing fuels. It seems to last longer than stock and heated O2 sensors. However in time the lead will clog up the sensor. Another alternative is a MaxEffort Digital Fuel Management system. It uses a thumbwheel to program the chip. MaxEffort keeps the ECM in an open loop, so an O2 sensor is not needed.
Website-MAXEFFORT Digital Programmable Fuel Management
PROM Chip-Part number-16051877,
California number-16036503
Diagnostic alarm code-51 PROM error
Location-The programmed read only memory (PROM) chip is the big computer chip located under the PROM access cover in the ECM.
Purpose-The PROM chip tells the ECM what to do.
How It Works-All of the fuel codes, ignition curves, TCC, etc are stored in the Prom chip. This is read only information, the ECM can not rewrite any of the information..
Torque Converter Clutch Solenoid-Part number-8639900
Location-You must remove the transmission pan. The TCC is located in the front of the transmission right behind the pan rail. Just follow the wires.
Purpose-The TCC sends the signal to lock the torque converter in overdrive.
How It Works- When signaled by the ECM the TCC will move the lock-up valve in the transmission. This will reverse the flow of transmission fluid and create pressure to lock the torque converter clutch up
Vehicle Speed Sensor-Part number-25007463,
AC Delco number-213-110
Diagnostic alarm code-24 vehicle speed sensor circuit failed
Location- There is two parts of a vehicle speed sensor (VSS). The first part is the reader, it is attached to the back of the speedometer. The second part is behind the stereo and heater controls. They are connected with a ribbon of three wires.
How it works-The VSS has a reader that is connected to the back of the speedometer. There are two reflective tabs on the back of the speedometer that the reader will count. Every turn of the speedometer cable results in two pulses. There are 2000 pulses in a mile. The reader will send the pulses to the module. The module will then decipher the pulses and send the information to the ECM. It is also used for cruise control.
Wastegate Solenoid-Part number-1997157,
AC Delco Part number-214-609
Location-The wastegate solenoid is located on the top of the passenger valve cover. It uses a red connector.
Diagnostic alarm code-31 wastegate solenoid electrical signal failed.
Purpose-The wastegate solenoid is how the ECM controls boost.
How it works-It is an electronic bleeder that uses pulses to release boost into the atmosphere if detonation is detected.
Doug Martin