2002 Mitsubishi Montero XLSFACTORY OEM SERVICE PROCEDURE

No Communication With Powertrain Control Module (PCM)

  1. Turn ignition off. Check PCM connector D-109 for loose, damaged, or corroded terminals. See Figure. If problem exists, repair or replace connector. If problem does not exist, go to next step.
  2. Check for open or short to ground in Gray/Red wire between OBD-II DLC terminal No. 1 and PCM connector D-109 terminal No. 84. See Figure and Figure . If problem exists, repair Gray/Red wire. If problem does not exist, go to next step.
  3. Check for open or short to ground in wire between OBD-II DLC terminal No. 7 (Red/White wire) and PCM connector D-109 terminal No. 85 (Green/Orange wire). If problem exists, repair Red/White wire or Green/Orange wire. If problem does not exist, go to next step.
  4. Remove MFI relay. See Figure. Check MFI relay connector for loose, damaged, or corroded terminals. If problem exists, repair or replace connector. If problem does not exist, go to next step.
  5. Check MFI relay. See FUEL PUMP RELAY & MFI RELAY under RELAYS under MOTORS, RELAYS & SOLENOIDS in SYSTEM & COMPONENT TESTING article. If problem exists, replace MFI relay. If problem does not exist, install MFI relay and go to next step.
  6. Measure voltage between ground and MFI relay connector terminals No. 2 and 3. See Figure. If battery voltage exists at both terminals, go to next step. If battery voltage does not exist at either or both terminals, repair White/Black wire between MFI relay connector and fusible link No. 6 (20-amp) located in engine compartment relay box.
  7. Disconnect PCM connector D-109. Check PCM connector D-109 for loose, damaged, or corroded terminals. If problem exists, repair or replace connector as necessary. If problem does not exist, go to next step.
  8. Turn ignition on. Measure voltage between ground and PCM connector D-109 terminal No. 98 (Blue/Black wire). See Figure. If battery voltage exists, go to next step. If battery voltage does not exist, check Blue/Black wire between ignition switch and PCM. If problem exists, repair Blue/Black between ignition switch and PCM. If problem does not exist, check ignition switch. Repair as necessary.
  9. Turn ignition off. Disconnect PCM 26-pin connector D-108. Measure voltage between ground and PCM connector D-108 terminal No. 66 (Red/Black wire). If battery voltage exists, go to next step. If battery voltage does not exist, repair Red/Black wire between PCM and fuse No. 7 (10-amp), located in engine compartment relay box.
  10. Check for continuity between ground and PCM connector D-108 terminals No. 42 (Black wire) and No. 48 (Black wire). If continuity exists at each terminal, go to next step. If continuity does not exist at either terminal, repair appropriate Black wire between ground and PCM.
  11. Measure voltage between ground and PCM connector D-108 terminal No. 49 (White/Blue wire). If battery voltage exists, go to next step. If battery voltage does not exist, repair White/Blue wire between PCM and MFI relay.
  12. Connect jumper wire between ground and PCM connector D-108 terminal No. 49 (White/Blue wire). MFI relay should audibly click. Measure voltage between ground and PCM connector D-108 terminals No. 41 (Red wire) and No. 47 (Red wire). If battery voltage exists at each terminal, replace PCM. If battery voltage does not exist at either terminal, repair appropriate Red wire between MFI relay and PCM.
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When to See a Mechanic

Stop DIY work and contact a certified mechanic immediately if any of the following apply:

  • • You smell fuel, burning insulation, or see smoke.
  • • Brakes feel soft, pull hard to one side, or make grinding noises.
  • • The engine overheats, stalls repeatedly, or misfires under load.
  • • You are missing required tools, torque specs, or safe lifting equipment.
  • • You are not confident in the next step or safety outcome.

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