Diagnostic Aids
An intermittent may be caused by the following:
- Poor connections.
- Mis routed harness.
- Rubbed through wire insulation.
- Broken wire inside the insulation.
Check for the following conditions:
- Poor connection at ECM - Inspect harness connectors for backed out terminals, improper mating, broken locks, improperly formed or damaged terminals, and poor terminal to wire connection.
- Damaged harness - Inspect the wiring harness for damage. If the harness appears to be OK, observe the APP sensor 1, APP sensor 2, APP sensor 3 display on the Tech 2 while moving connectors and wiring harnesses related to the sensor.
A change in the display will indicate the location of the fault. If DTC P1290 cannot be duplicated, the information included in the Failure Records data can be useful in determined vehicle mileage since the DTC was last set.
If it is determined that the DTC occurs intermittently, performing the DTC P1290 Diagnostic Chart may isolate the cause of the fault.
DTC P1290 - ELECTRONIC THROTTLE CONTROL FORCED IDLE MODE
| Step | Action | Values | Yes | No |
|---|---|---|---|---|
| 1 | Was the "On-Board Diagnostic (OBDII) System Check performed? | - | Go to Step 2 | Go to On-Board Diagnostic (OBD-II) System Check |
| 2 | Using Tech 2, All of the following P-codes are stored. P1275, P1271, P1280, P1272, P1285, P1273 were stored? |
- | Refer to ECM Diagnostic Trouble Codes | Go to Step 3 |
| 3 | Install the test ECM. Program the test ECM (Immobilizer system). Refer to IMMOBILIZER SYSTEM . Check the OBD-II test for following condition:
Did the DTC disappear? |
- | Go to Step 4 | Go to Step 2 |
| 4 | Replace the original ECM. Check the poor connection between the ECM and ECM connector. Recheck the OBD-II test again. When the engine is started. Did the DTC disappear? |
- | Verify repair | Go to Step 5 |
| 5 | Disconnect the ABS control unit connector. Reprogramming the original ECM. (Engine control and Immobilizer control) Recheck the OBD-II. Did the DTC disappear? |
- | Verify repair | Go to Step 6 |
| 6 | Replace the ECM. Recheck the OBD-II test again. Did the DTC disappear? |
- | Verify repair | Refer to DIAGNOSTIC AIDS |