Diagnostic Aids
Check for the following conditions:
- Poor connection at ECM and Immobilizer - 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, disconnect the ECM and Immobilizer, turn the ignition "ON" and observe a voltmeter connected to the suspect driver circuit at the ECM and Immobilizer harness connector while moving connectors and wiring harnesses relates to the Immobilizer Warning Lamp.
A change in voltage will indicate the location of the fault.
DTC P1649 - IMMOBILIZER FUNCTION NOT PROGRAMMED
| 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 the Tech 2 system selection menu, select Body function. Does the Tech 2 display B**** appear? |
- | Refer to IMMOBILIZER SYSTEM | Go to Step 3 |
| 3 | Install the test ECM. Programming 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 |