FREE REPAIR MANUALS & LABOR GUIDES 1982-2013 Vehicles
Courtesy of Operation CHARM: Car repair manuals for everyone.
Home >> Chevrolet >> 2012 >> Volt L4-1.4L Elect >> Repair and Diagnosis >> A L L Diagnostic Trouble Codes ( DTC ) >> Testing and Inspection >> P Code Charts >> P0108

P0108




DTC P0107 or P0108

Diagnostic Instructions

* Perform the Diagnostic System Check - Vehicle Diagnostic System Check - Vehicle prior to using this diagnostic procedure.
* Review Strategy Based Diagnosis Strategy Based Diagnosis for an overview of the diagnostic approach.
* Diagnostic Procedure Instructions Diagnostic Procedure Instructions provides an overview of each diagnostic category.

DTC Descriptors
DTC P0107
- Manifold Absolute Pressure (MAP) Sensor Circuit Low Voltage

DTC P0108
- Manifold Absolute Pressure (MAP) Sensor Circuit High Voltage

Diagnostic Fault Information






Typical Scan Tool Data






Circuit Description

The manifold absolute pressure (MAP) sensor measures the pressure inside the intake manifold. Pressure in the intake manifold is affected by engine speed, throttle opening, air temperature, and barometric pressure (BARO). A diaphragm within the MAP sensor is displaced by the pressure changes that occur from the varying load and operating conditions of the engine. The sensor translates this action into electrical resistance. The MAP sensor wiring includes 3 circuits. The engine control module (ECM) supplies a regulated 5 V to the sensor on a 5 V reference circuit. The ECM supplies a ground on a low reference circuit. The MAP sensor provides a signal voltage to the ECM, relative to the pressure changes, on the MAP sensor signal circuit. The ECM converts the signal voltage input to a pressure value.

Under normal operation the highest pressure that can exist in the intake manifold is equal to BARO. This occurs when the engine is operated at wide-open throttle (WOT) or when the vehicle is ON while the engine is OFF. Under these conditions, the ECM uses the MAP sensor to determine the current BARO. The lowest manifold pressures occur when the vehicle is idling or decelerating. MAP can range from 1.5 psi, when pressures are low, to as much as 15 psi when pressures are high, depending on the BARO. The ECM monitors the MAP sensor signal for pressure outside of the normal range.

Conditions for Running the DTC

These DTCs run continuously.

Conditions for Setting the DTC

P0107

The ECM detects that the MAP sensor voltage is less than 0.2 V for greater than 4 s.

P0108

The ECM detects that the MAP sensor voltage is greater than 4.5 V for greater than 4 s.

Action Taken When the DTC Sets

DTCs P0107 and P0108 are Type B DTCs.

Conditions for Clearing the MIL/DTC

DTCs P0107 and P0108 are Type B DTCs.

Reference Information
Schematic Reference

Engine Controls Schematics [1][2]Electrical Diagrams
Connector End View Reference

Component Connector End Views Hybrid/EV Battery Pack X1
Description and Operation

Hybrid Modes of Operation Description Hybrid Modes of Operation Description
Electrical Information Reference

* Circuit Testing Circuit Testing
* Connector Repairs Connector Repairs
* Testing for Intermittent Conditions and Poor Connections Testing for Intermittent Conditions and Poor Connections
* Wiring Repairs Wiring Repairs

DTC Type Reference

Powertrain Diagnostic Trouble Code (DTC) Type Definitions Powertrain Diagnostic Trouble Code (DTC) Type Definitions
Scan Tool Reference

Control Module References Programming and Relearning for scan tool information
Special Tools

J-23738-A - Vacuum Pump

For equivalent regional tools, refer to Special Tools (Diagnostic Tools) Special Tools (Diagnostic Tools).

Circuit/System Verification

1. Vehicle in Service Mode, verify DTC P0697 is not set.

• If a DTC is set, refer to DTC P0641, P0651, P0697, or P06A3 (ECM) Powertrain Management (ECM).

2. Vehicle in Service Mode, observe the scan tool MAP sensor parameter. Engine running, the MAP Sensor parameter should change.
3. Operate the vehicle within the conditions for running the DTC to verify the DTC does not reset. You may also operate the vehicle within the conditions that you observed from the freeze frame/failure records data.

Circuit/System Testing

1. Vehicle OFF, disconnect the harness connector at the B74 MAP sensor.
2. Vehicle OFF, all systems OFF. It may take up to 2 minutes for all vehicle systems to power down. Test for less than 5 ohm between the low reference circuit terminal 2 and ground.

• If greater than the specified value, test the low reference circuit for an open/high resistance. If the circuit tests normal, replace the K20 ECM.

3. Vehicle in Service Mode, test for 4.8-5.2 V between the 5 V reference circuit terminal 1 and ground.

• If less than the specified range, test the 5 V reference circuit for a short to ground or an open/high resistance. If the circuit tests normal, replace the K20 ECM.
• If greater than the specified range, test the 5 V reference circuit for a short to voltage. If the circuit tests normal, replace the K20 ECM.

4. Verify the scan tool MAP Sensor parameter is less than 0.5 V.

• If greater than the specified range, test the signal circuit terminal 3 for a short to voltage. If the circuit tests normal, replace the K20 ECM.

5. Install a 3 A fused jumper wire between the signal circuit terminal 3 and the 5 V reference circuit terminal 1. Verify the scan tool MAP Sensor parameter is greater than 4.7 V.

• If less than the specified range, test the signal circuit for a short to ground or an open/high resistance. If the circuit tests normal, replace the K20 ECM.

6. If all circuits test normal, test or replace the B74 MAP sensor.

Component Testing

Note: You must perform the Circuit/System Testing in order to verify the integrity of the MAP sensor circuits before proceeding with the Component Testing.

Skewed Sensor Test
1. Vehicle in Service Mode, observe the MAP sensor scan tool parameter.
2. Use the observed MAP Sensor scan tool parameter that is closest to a value that is indicated in the first column of the table.
3. Connect the J-23738-A - to the port of the B74 MAP sensor.
4. Apply 5 in Hg of vacuum to the B74 MAP sensor, with the J-23738-A - . The MAP sensor parameter in the first column of the table should decrease by 2.5 psi. The acceptable range is indicated in the second column of the table.
5. Apply 10 in Hg of vacuum to the B74 MAP sensor using the J-23738-A - . The MAP sensor parameter in the first column of the table should decrease by 5 psi. The acceptable range is indicated in the third column of the table.





Erratic Signal Test
1. Vehicle OFF, remove the B74 MAP sensor.
2. Install a 3 A fused jumper wire between the 5 V reference circuit terminal 1 and the corresponding terminal of the B74 MAP sensor.
3. Install a jumper wire between the low reference terminal 2 of the B74 MAP sensor and ground.
4. Install a jumper wire at terminal 3 of the B74 MAP sensor.
5. Connect a DMM between the jumper wire from the terminal 3 of the B74 MAP sensor and ground.
6. Vehicle in Service Mode, with the J-23738-A - , slowly apply vacuum to the sensor while observing the voltage on the DMM. The voltage should vary between 4.9-0.2 V without any spikes or dropouts.

• If the voltage is erratic, replace the B74 MAP sensor.

Repair Instructions

Perform the Diagnostic Repair Verification Verification Tests after completing the diagnostic procedure.

* Manifold Absolute Pressure Sensor Replacement Service and Repair
* Control Module References Programming and Relearning for ECM replacement, setup, and programming

pro multis Credits:Operation CHARM About Operation CHARM