Circuit Description
The engine control module (ECM) is the control center of the fuel injection system. It constantly looks at the information from various sensors, and controls the systems that affect vehicle performance. The ECM also performs the diagnostic function of the system. It can recognize operational problems, alert the driver through the malfunction indicator lamp (MIL), check engine, and store a diagnostic trouble code (DTC) or DTCs which identify the problem areas to aid the technician in making repairs. The ECM detects communication link failure with immobilizer control unit.
DTC Descriptor
This diagnostic procedure supports the following DTC:
DTC P1626 Theft Deterrent Fuel Enable Signal Lost.
Conditions for Setting the DTC
| • | No immobilizer message identification for ECM release time window, 1.5 or 2.0 seconds |
| • | The ignition switch is turned to ON. |
| • | The ECM release time window expired. |
Action Taken When the DTC Sets
| • | The malfunction indicator lamp (MIL) will not illuminate. |
| • | The ECM will record operating conditions at the time the diagnostic fails. This information will be stored in the failure record buffers. |
| • | A history DTC is stored. |
Conditions for Clearing the MIL/DTC
| • | A history DTC will clear after 40 consecutive warm-up cycles without a fault. |
| • | DTCs can be cleared by using the scan tool. |
| • | Disconnect the ECM battery feed for more than 10 seconds. |
Step | Action | Yes | No |
|---|---|---|---|
1 | Did you perform the Diagnostic System Check - Engine Controls? | Go to Step 2 | |
2 |
Did you complete the replacement? | Go to Step 3 | -- |
3 |
Did the DTC fail this ignition? | Go to Step 2 | Go to Step 4 |
4 | Observe the Capture Info with a scan tool. Are there any DTCs that have not been diagnosed? | System OK |
