Diesel Engine Management System

OBD System Troubleshooting (cont'd)

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Malfunction Indicator Lamp (MIL) ON Steady

  1. Check the ''On Board Diagnostic (OBD) System Check''.

Was the OBD System Check performed?

YES – Go to step 2.

NO – Go to OBD System Check.

  1. Turn the ignition switch OFF.
  1. Disconnect ECM A connector.
  1. Turn the ignition switch ON (II).

Does the MIL come ON?

YES – Go to step 5.

NO – Substitute a known-good ECM and recheck. If symptom/indication goes away, replace the original ECM.

  1. Turn the ignition switch OFF.
  1. Disconnect meter connector.
  1. Check for short to ground in the wire between the ECM A connector terminal No. 15 and meter connector terminal No. 18.

Is a problem found?

YES – Repair for short to ground in the wire.

NO – Go to step 8.

  1. Check for the following conditions:
  • Damaged meter assembly
  • Dirt on the wire in the meter assembly

Is a problem found?

YES – Repair an open in the wire.

NO – Replace the meter assembly.