2002 Chevy Cavalier

Tiny
STEVE EUDY
  • MEMBER
  • 2002 CHEVROLET CAVALIER
  • 4 CYL
  • FWD
  • AUTOMATIC
  • 51,000 MILES
2002 Chevy Cavalier, 2.2 OHV, 51,000 miles, CA emissions. This car runs very well except on cold start up, when the ambient temperature is below 35 degrees. Then it starts well and runs well until it reaches operating temperature (195 degrees). At this point when it should go to close loop it stalls at deceleration. It starts right back (guess it changes to close loop ) and runs find till the next cold start up. I get no check engine light, scanner shows no (DTCs). Intake Air Temp. Sensor, Engine Coolant Temp. Sensor and all sensors read good on scanner. I haven’t been able to get the scanner on it during the cold ambient conditions, as here in NC it may be 20 degrees one morning and 60 degrees the next. I can generally fix my own cars, but I’m puzzled about this one. I can actually watch the Temp. Guage and know when it is going to stall. What should I be checking? Thanks much, Steve
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Thursday, February 26th, 2009 AT 9:27 PM

3 Replies

Tiny
DAVE H
  • EXPERT
Check/clean or replace the MAF sensor !
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Friday, February 27th, 2009 AT 8:01 PM
Tiny
STEVE EUDY
  • MEMBER
Thanks for the reply! This model not using a Mass Air Flow sensor. Has a Manifold Absolute Pressure sensor and upstream and downstream O2 sensor. (MAP) is not showing a voltage problem on scanner and shows a reading of 9.7 (hg) @ 600rpm. I'm not sure what the parameters are on fuel mixture and without DTC's I feel like I'll be spitting in the wind changing parts. Thanks again, Steve
FYI.I'm a NATE ceft. HVAC-Refrigerarion Tech, maybe I can help you sometime.
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Saturday, February 28th, 2009 AT 12:00 AM
Tiny
DAVE H
  • EXPERT
DTC P0107: MAP SENSOR CIRCUIT - LOW VOLTAGE
NOTE:For circuit reference, see WIRING DIAGRAMS article. For component locations, see COMPONENT LOCATIONS. For connector identification, see CONNECTOR IDENTIFICATION.

Description
The Manifold Absolute Pressure (MAP) sensor responds to pressure changes in the intake manifold. The pressure changes occur based on the engine load. The MAP sensor has the following circuits: 5-volt reference circuit, low reference circuit and MAP sensor signal circuit.
The Powertrain Control Module (PCM) supplies 5 volts to the MAP sensor on the 5-volt reference circuit. The PCM also provides a ground on the low reference circuit. The MAP sensor provides a signal to the PCM on the MAP sensor signal circuit which is relative to the pressure changes in the manifold. The PCM should detect a low signal voltage at a low MAP, such as during an idle or a deceleration. The PCM should detect a high signal voltage at a high MAP, such as the ignition is ON, with the engine OFF, or at a Wide Open Throttle (WOT). The MAP sensor is also used in order to determine the Barometric Pressure (BARO). This occurs when the ignition switch is turned ON, with the engine OFF. The BARO reading may also be updated whenever the engine is operated at WOT. The PCM monitors the MAP sensor signal for voltage outside of the normal range.
If the PCM detects a MAP sensor signal voltage that is excessively low, DTC P0107 will set.
Conditions For Running DTC
DTCs P0122 or P0123 are not set.
The engine speed is less than 1000 RPM or the engine speed is more than 1000 RPM and Throttle Position (TP) is more than 15 percent.
Conditions For Setting DTC
The MAP sensor voltage is less than 0.2 volt for at least 6.25 seconds.
Actions Taken When DTC Sets
The control module illuminates the Malfunction Indicator Light (MIL) on the second consecutive ignition cycle that the diagnostic runs and fails.
The control module records the operating conditions at the time the diagnostic fails. The first time the diagnostic fails, the control module stores this information in the Failure Records. If the diagnostic reports a failure on the second consecutive ignition cycle, the control module records the operating conditions at the time of the failure. The control module writes the operating conditions to the Freeze Frame and updates the Failure Records.
Conditions For Clearing MIL/DTC
The control module turns OFF the Malfunction Indicator Light (MIL) after 3 consecutive ignition cycles that the diagnostic runs and does not fail.
A current DTC, Last Test Failed, clears when the diagnostic runs and passes.
A history DTC clears after 40 consecutive warm-up cycles, if no failures are reported by this or any other emission related diagnostic.
Clear the MIL and DTC with a scan tool.
Test Conditions
The number below refers to the step number on the diagnostic procedure.
3

Operate the vehicle within the same conditions which caused the DTC to fail. If you cannot duplicate the DTC, the information included in the Freeze Frame/Failure Records can aid in locating an intermittent condition.
Diagnostic Procedures
Perform diagnostic system check - engine controls. See DIAGNOSTIC SYSTEM CHECK - ENGINE CONTROLS under SELF-DIAGNOSTIC SYSTEM. After performing diagnostic system check - engine controls, go to next step.
Turn ignition on, with engine off. With a scan tool, observe MAP sensor voltage. Does the scan tool indicate that the voltage is less than 0.2 volt? If yes, go to step 4. If no, go to next step.
Observe the Freeze Frame/Failure Records for this DTC. Turn ignition off for 30 seconds. Start engine. Operate the vehicle within the Conditions for Running the DTC or within the conditions in the Freeze Frame/Failure Records. See CONDITIONS FOR RUNNING DTC. Does the DTC fail this ignition? If yes, go to next step. If no, go to DIAGNOSTIC AIDS.
Turn ignition off. Disconnect MAP sensor electrical connector. Turn ignition on, with engine off. Measure the voltage from the 5-volt reference circuit of the MAP sensor to a good ground. Does the voltage measure about 5 volts? If yes, go to next step. If no, go to step 6.
Connect a 3-amp fused jumper wire between the 5-volt reference circuit of the MAP sensor and the signal circuit of the MAP sensor. Does the scan tool indicate that the voltage is about 5 volts? If yes, go to step 8. If no, go to next step.
Test the 5-volt reference circuit of the MAP sensor for a short to ground or an open. Did you find and correct the condition? If yes, go to step 12. If no, go to step 9.
Test the signal circuit of the MAP sensor for a short to ground or an open. Did you find and correct the condition? If yes, go to step 12. If no, go to next step.
Inspect for faulty connections at the MAP sensor. Did you find and correct the condition? If yes, go to step 12. If no, go to step 10.
Inspect for faulty connections at the PCM. Did you find and correct the condition? If yes, go to step 12. If no, go to step 11.
Replace MAP sensor. After replacing sensor, go to step 12.
Replace PCM. See POWERTRAIN CONTROL MODULE in appropriate REMOVAL, OVERHAUL & INSTALLATION article. Perform PCM relearn procedure. See POWERTRAIN CONTROL MODULE REPROGRAMMING under PROGRAMMING. After replacing PCM, go to next step.
Use the scan tool in order to perform the Fuel Trim Reset procedure. When complete, go to next step.
Using scan tool, clear DTCs. Turn ignition off for 30 seconds. Start engine. Operate the vehicle within the Conditions for Running the DTC. See CONDITIONS FOR RUNNING DTC. Does the DTC run and pass? If yes, go to next step. If no, go to step 2.
Using scan tool, observe stored information. If any DTCs are displayed that have not been diagnosed, see DIAGNOSTIC TROUBLE CODE DEFINITIONS.
Diagnostic Aids
The PCM uses a single 5-volt reference output to supply power to all of the engine control components. If a components 5-volt reference circuit is shorted to ground or shorted to voltage, the other 5-volt reference circuits may be affected.
If this DTC is determined to be intermittent, refer to INTERMITTENT CONDITIONS under SELF-DIAGNOSTIC SYSTEM.
DTC P0108: MAP SENSOR CIRCUIT - HIGH VOLTAGE
NOTE:For circuit reference, see WIRING DIAGRAMS article. For component locations, see COMPONENT LOCATIONS. For connector identification, see CONNECTOR IDENTIFICATION.

Description
The Manifold Absolute Pressure (MAP) sensor responds to pressure changes in the intake manifold. The pressure changes occur based on the engine load. The MAP sensor has the following circuits: 5-volt reference circuit, low reference circuit and MAP sensor signal circuit.
The Powertrain Control Module (PCM) supplies 5 volts to the MAP sensor on the 5-volt reference circuit. The PCM also provides a ground on the low reference circuit. The MAP sensor provides a signal to the PCM on the MAP sensor signal circuit which is relative to the pressure changes in the manifold. The PCM should detect a low signal voltage at a low MAP, such as during an idle or a deceleration. The PCM should detect a high signal voltage at a high MAP, such as the ignition is ON, with the engine OFF, or at a Wide Open Throttle (WOT). The MAP sensor is also used in order to determine the Barometric Pressure (BARO). This occurs when the ignition switch is turned ON, with the engine OFF. The BARO reading may also be updated whenever the engine is operated at WOT. The PCM monitors the MAP sensor signal for voltage outside of the normal range.
If the PCM detects a MAP sensor signal voltage that is excessively high, DTC P0108 will set.
Conditions For Running DTC
DTCs P0122 or P0123 are not set.
The Throttle Position (TP) is less than 12 percent.
The vehicle speed is less than 1 MPH.
The engine run time is more than 20-40 seconds.
Conditions For Setting DTC
The MAP sensor voltage is more than 3.8 volts for at least 1.25 seconds.
Actions Taken When DTC Sets
The control module illuminates the Malfunction Indicator Light (MIL) on the second consecutive ignition cycle that the diagnostic runs and fails.
The control module records the operating conditions at the time the diagnostic fails. The first time the diagnostic fails, the control module stores this information in the Failure Records. If the diagnostic reports a failure on the second consecutive ignition cycle, the control module records the operating conditions at the time of the failure. The control module writes the operating conditions to the Freeze Frame and updates the Failure Records.
Conditions For Clearing MIL/DTC
The control module turns OFF the Malfunction Indicator Light (MIL) after 3 consecutive ignition cycles that the diagnostic runs and does not fail.
A current DTC, Last Test Failed, clears when the diagnostic runs and passes.
A history DTC clears after 40 consecutive warm-up cycles, if no failures are reported by this or any other emission related diagnostic.
Clear the MIL and DTC with a scan tool.
Test Description
The number below refers to the step number on the diagnostic procedure.
3

Operate the vehicle within the same conditions which caused the DTC to fail. If you cannot duplicate the DTC, the information included in the Freeze Frame/Failure Records data can aid in locating an intermittent condition.
Diagnostic Procedures
Perform diagnostic system check - engine controls. See DIAGNOSTIC SYSTEM CHECK - ENGINE CONTROLS under SELF-DIAGNOSTIC SYSTEM. After performing diagnostic system check - engine controls, go to next step.
Start engine. Let engine idle. Does the scan tool indicate that the MAP sensor voltage is greater than 3.8 volts? If yes, go to step 4. If no, go to next step.
Observe the Freeze Frame/Failure Records for this DTC. Turn ignition off for 30 seconds. Start engine. Operate the vehicle within the Conditions for Running the DTC or within the conditions in the Freeze Frame/Failure Records. See CONDITIONS FOR RUNNING DTC. Does the DTC fail this ignition? If yes, go to next step. If no, go to DIAGNOSTIC AIDS.
Turn ignition off. Inspect the MAP sensor vacuum source for leaks, faulty connections or restrictions. Did you find and correct the condition? If yes, go to step 15. If no, go to next step.
Disconnect MAP sensor electrical connector. Turn ignition on, with engine off. Does the scan tool indicate that the MAP sensor voltage is less than 0.2 volt? If yes, go to next step. If no, go to step 8.
Measure the voltage from the 5-volt reference circuit to the low reference circuit at the MAP sensor electrical connector. Does the voltage measure within 4.7-5.2 volts? If yes, go to step 11. If no, go to next step.
Does the voltage measure more than 5.2 volts? If yes, go to step 10. If no, go to step 9.
Test the signal circuit of the MAP sensor for a short to voltage. Did you find and correct the condition? If yes, go to step 15. If no, go to step 12
Test the low reference circuit of the MAP sensor for an open. Did you find and correct the condition? If yes, go to step 15. If no, go to step 12.
Test the 5-volt reference circuit of the MAP sensor for a short to voltage. Did you find and correct the condition? If yes, go to step 15. If no, go to step 12.
Inspect for faulty connections at the MAP sensor. Did you find and correct the condition? If yes, go to step 15. If no, go to step 13.
Inspect for faulty connections at the PCM. Did you find and correct the condition? If yes, go to step 15. If no, go to step 14.
Replace MAP sensor. When complete, go to step 15.
Replace PCM. See POWERTRAIN CONTROL MODULE in appropriate REMOVAL, OVERHAUL & INSTALLATION article. Perform PCM relearn procedure. See POWERTRAIN CONTROL MODULE REPROGRAMMING under PROGRAMMING. After replacing PCM, go to step 16.
Use the scan tool in order to perform the Fuel Trim Reset procedure. When complete, go to next step.
Using scan tool, clear DTCs. Turn ignition off for 30 seconds. Start engine. Operate the vehicle within the Conditions for Running the DTC. See CONDITIONS FOR RUNNING DTC. Does the DTC run and pass? If yes, go to next step. If no, go to step 2.
Using scan tool, observe stored information. If any DTCs are displayed that have not been diagnosed, see DIAGNOSTIC TROUBLE CODE DEFINITIONS.
Diagnostic Aids
This DTC may set when attempting to start a vehicle that is out of fuel.
The PCM uses a single 5-volt reference output to supply power to all of the engine control components. If a component's 5-volt reference circuit is shorted to ground or shorted to voltage, the other 5-volt reference circuits may be affected.
Inspect the MAP sensor vacuum source for leaks, restrictions or faulty connections.
This DTC may set as the result of a misfire.
If this DTC is determined to be intermittent, refer to INTERMITTENT CONDITIONS under SELF-DIAGNOSTIC SYSTEM.
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Saturday, February 28th, 2009 AT 5:22 AM

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