Test No. 1: Scan Tool Communication Not Possible
WARNING: This page is about a different car, the 2001 Mitsubishi Montero Sport. However, it is still accessible from the selected car via links, so may be relevant.
- Check if scan tool can communicate with Powertrain Control Module (PCM). If scan tool cannot communicate with PCM, diagnose communication problem. See SELF-DIAGNOSTICS - MONTERO SPORT article in ENGINE PERFORMANCE. If scan tool will communicate with PCM, check if PCM DTCs other than P1610 set. If PCM DTC other than P1610 sets, diagnose DTC. See SELF-DIAGNOSTICS - MONTERO SPORT article in ENGINE PERFORMANCE. If no PCM DTCs other than PCM DTC P1610 set, go to next step.
- Turn ignition on. Backprobe immobilzer-ECU 12-pin connector. Measure voltage between ground and immobilizer-ECU connector terminal No. 7 (Red wire). See Figure . If battery voltage exists, go to step 4 . If battery voltage does not exist, go to next step.
- Check immobilizer-ECU and MFI relay connectors for loose, damaged or corroded terminals. Check for open or short to ground in Red wire between MFI relay connector terminal No. 1 and immobilizer-ECU connector terminal No. 7. See Fig 1 . Repair connector(s) or Red wire as necessary.
- Turn ignition off. Measure resistance between ground and immobilizer-ECU connector terminal No. 3 (Black wire). If resistance is less than 2 ohms, go to next step. If resistance is 2 ohms or more, go to step 6 .
- Check immobilizer-ECU connector for loose, damaged or corroded terminals. Check for open in Black wire between immobilizer-ECU and ground. Repair connector or Black wire as necessary.
- Check for open or short in Yellow wire between immobilizer-ECU connector terminal No. 5 and PCM connector C-92 terminal No. 111. See Fig 2
andFigure
. If problem exists, repair Yellow wire as necessary. If problem does not exist, replace immobilizer-ECU and go to next step.CAUTION: DO NOT register new immobilizer-ECU at this stage, otherwise immobilizer-ECU will have to be replaced again if PCM is replaced due to malfunction.
- Check for scan tool communication with immobilizer-ECU. If scan tool can communicate with immobilizer-ECU, register password and ignition key encrypted code. See PROGRAMMING . If scan tool cannot communicate with immobilizer-ECU, replace PCM and ignition key. Register password and ignition key encrypted code.