Charging System Indicator Circuit Troubleshooting
  1. Turn the ignition switch ON (II).
Does the charging system indicator come on?
YES -
Go to Step 2 .
NO -
Go to Step 14 .
  1. Start the engine. Hold the engine speed at 2,000 rpm (min −1 ) for 1 minute.
Does the charging system indicator go off?
YES -
Charging system indicator circuit is OK. Go to the alternator and regulator circuit troubleshooting. ■
NO -
Go to Step 3 .
Does the charging system indicator flash?
YES -
Go to Step 4 .
NO -
Replace the gauge control module.■
  1. Turn the ignition switch OFF.
  1. Disconnect the alternator 4P connector.
  1. Turn the ignition switch ON (II).
    NOTE: The charging system indicator may come on and then go off.
Does the charging system indicator go off?
YES -
NO -
Go to Step 7 .
  1. Turn the ignition switch OFF.
  1. Turn the ignition switch ON (II).
  1. Jump the SCS line with the HDS, then turn the ignition switch OFF.
    NOTE: This step must be done to protect the ECM from damage.
  1. Disconnect ECM connector B (44P).
  1. Check for continuity between ECM connector terminal B42 and body ground.
Is there continuity?
YES -
Repair short in the wire between the alternator and the ECM.■
NO -
Update the ECM if it does not have the latest software, or substitute a known-good ECM, then recheck. If the symptom/indication goes away with a known-good ECM, replace the original ECM. ■
Does the charging system indicator flash?
YES -
Go to Step 15 .
NO -
Replace the gauge control module.■
  1. Turn the ignition switch OFF.
  1. Disconnect the alternator 4P connector.
  1. Connect alternator 4P connector terminal No. 3 and body ground with a jumper wire.
  1. Turn the ignition switch ON (II).
Does the charging system indicator come on?
YES -
NO -
Go to Step 19 .
  1. Turn the ignition switch ON (II).
  1. Jump the SCS line with the HDS, then turn the ignition switch OFF.
    NOTE: This step must be done to protect the ECM from damage.
  1. Disconnect ECM connector B (44P).
  1. Check for continuity between ECM connector terminal B42 and body ground.
Is there continuity?
YES -
Update the ECM if it does not have the latest software, or substitute a known-good ECM, then recheck. If the symptom/indication goes away with a known-good ECM, replace the original ECM. ■
NO -
Repair open in the wire between the alternator and the ECM.■