Circuit Description
The powertrain control module (PCM) is the control center of the fuel injection system. The PCM constantly monitors the information from various sensors and controls the systems that affect vehicle performance. The PCM also performs the diagnostic function of the system. The PCM can recognize operational problems, alert the driver through the malfunction indicator lamp (MIL), and store a DTC or DTCs which identify the problem areas in order to aid the technician in making repairs.
Conditions for Setting the DTC
The PCM cannot communicate internally.
Action Taken When the DTC Sets
| • | The malfunction indicator lamp (MIL) will illuminate. |
| • | The PCM will attempt to record the operating conditions at the time of this failure. However, since this is an internal PCM failure, the information may be unreliable. This information will store in the Freeze Frame and Failure Records buffers. |
| • | A history DTC stores. |
Conditions for Clearing the MIL/DTC
| • | The MIL will turn off after 3 consecutive ignition cycles in which the diagnostic runs without a fault. |
| • | A history DTC will clear after 40 consecutive warm up cycles without a fault. |
| • | Use a scan tool to clear the DTCs. |
Test Description
The number below refers to the step number on the diagnostic table.
Step | Action | Values | Yes | No |
|---|---|---|---|---|
1 | Did you perform the Powertrain On-Board Diagnostic (OBD) System Check? | -- | Go to Step 2 | |
|
Important:: The replacement PCM must be programmed. Refer to Powertrain Control Module Replacement/Programming . Replace the PCM. Refer to Powertrain Control Module Replacement . Did you complete the repair? | -- | Go to Step 3 | -- | |
3 |
Does the DTC reset? | -- | Go to Step 2 | System OK |
