DTC P0108 Without RPO CTF
Circuit Description
The barometric pressure (BARO) sensor is part of the engine control module (ECM).
If the ECM detects a signal voltage that is excessively low voltage DTC P0107 will set. If the ECM detects a signal voltage that is excessively high DTC P0108 will set.
Conditions for Setting the DTC
| • | The BARO sensor voltage is more than 4.7 volts. |
| • | The above conditions is met for more than 1 second. |
Action Taken When the DTC Sets
The ECM will operate the vehicle based on a BARO pressure of 100 kPa (14.5 psi).
Conditions for Clearing the DTC
| • | A current DTC Last Test Failed clears when the diagnostic runs and passes. |
| • | Clear the DTC with a scan tool. |
Step | Action | Yes | No |
|---|---|---|---|
Schematic Reference: Engine Controls Schematics | |||
1 | Does the DTC set while the ignition is ON and the engine is running? | Go to Step 2 | Go to Intermittent Conditions |
2 | Clear the DTCs. Does The DTC reset? | Go to Step 3 | Go to Step 5 |
3 | Replace the ECM. Did you complete the replacement? | Go to Step 4 | -- |
4 | Clear the DTCs. Does the DTC reset? | Go to Step 2 | Go to Step 5 |
5 | Operate the vehicle. Do any other DTCs set? | System OK | |
DTC P0108 With RPO CTF
Circuit Description
The barometric pressure (BARO) sensor is installed inside of the engine control module (ECM) and converts the BARO into a voltage signal. The ECM uses this voltage signal to calibrate the fuel injection quantity and injection timing for altitude compensation. If the ECM detects an excessively high BARO signal voltage, this DTC will set.
Conditions for Running the DTC
| • | The ignition switch is ON. |
| • | The battery voltage is between 10-16 volts. |
Conditions for Setting the DTC
The ECM detects that the BARO signal voltage is more than 4.5 volts.
Action Taken When the DTC Sets
| • | The ECM illuminates the malfunction indicator lamp (MIL) when the diagnostic runs and fails. |
| • | The ECM records the operating conditions at the time the diagnostic fails. The ECM stores this information in the Failure Records. |
| • | The ECM uses a barometric pressure substitution of 14.7 psi (101.3 kPa) when the DTC is set. |
| • | The ECM closes the exhaust gas recirculation (EGR) valve and holds it to the closed position. |
Condition for Clearing the DTC
| • | A current DTC, Last Test Failed, clears when the diagnostic runs and passes. |
| • | Clear the MIL and the DTC with a scan tool. |
Step | Action | Values | Yes | No |
|---|---|---|---|---|
Schematic Reference: Engine Controls Schematics | ||||
1 | Did you perform the Diagnostic System Check - Engine Controls? | -- | Go to Step 2 | |
2 |
Did the DTC fail this ignition? | -- | Go to Step 3 | Go to Step 4 |
3 |
Important: The new engine control module (ECM) must be programmed. Replace the ECM. Refer to Engine Control Module Replacement/Restore Fuel Rate Data . Did you complete the replacement? | -- | Go to Step 4 | -- |
4 |
Did the DTC fail this ignition? | -- | Go to Step 2 | Go to Step 5 |
5 | Observe the Capture Info with a scan tool. Are there any DTCs that have not been diagnosed? | -- | System OK | |
