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F-CAN Circuit Troubleshooting

NOTE: Information marked with an asterisk ( * ) applies to the CANL line.
  1. Turn the ignition switch to LOCK (0).
  1. Jump the SCS line with the HDS.
  1. Disconnect ECM/PCM connector A (49P), then disconnect the HDS.
  1. Measure the resistance between ECM/PCM connector terminals A3 and A4.
Is there about 95−116 Ω?
YES -
Go to Step 27 .
NO -
Go to Step 5 .
  1. Disconnect these connectors:

  1. Check for continuity between ECM/PCM connector terminals A3 and A4.
Is there continuity?
YES -
Repair short in the wire between ECM/PCM terminals A3 and A4 * .■
NO -
Go to Step 7 .

  1. Connect ECM/PCM connector terminal A3 to body ground with a jumper wire.

  1. Check for continuity between gauge control module 32P connector terminal No. 30 and body ground.
Is there continuity?
YES -
NO -
Repair open in the wire between the ECM/PCM (A3) and the gauge control module.■

  1. Check for continuity between ABS modulator-control unit 25P connector terminal No. 1 and body ground.
Is there continuity?
YES -
Go to Step 10 .
NO -
Repair open in the wire between the ECM/PCM (A3) and the ABS modulator-control unit.■

  1. Check for continuity between EPS control unit connector C (16P) terminal No. 10 and body ground.
Is there continuity?
YES -
Go to Step 11 .
NO -
Repair open in the wire between the ECM/PCM (A3) and the EPS control unit.■
  1. Remove the jumper wire from ECM/PCM connector A (49P).

  1. Connect ECM/PCM connector terminal A4 to body ground with a jumper wire.

  1. Check for continuity between gauge control module 32P connector terminal No. 29 and body ground.
Is there continuity?
YES -
NO -
Repair open in the wire between the ECM/PCM (A4) and the gauge control module.■

  1. Check for continuity between ABS modulator-control unit 25P connector terminal No. 17 and body ground.
Is there continuity?
YES -
Go to Step 15 .
NO -
Repair open in the wire between the ECM/PCM (A4) and the ABS modulator-control unit.■

  1. Check for continuity between EPS control unit connector C (16P) terminal No. 9 and body ground.
Is there continuity?
YES -
Go to Step 16 .
NO -
Repair open in the wire between the ECM/PCM (A4) and the EPS control unit.■
  1. Reconnect the gauge control module 32P connector.

  1. Measure the resistance between ECM/PCM connector terminals A3 and A4.
Is there about 108−132 Ω?
YES -
NO -
  1. Disconnect the gauge control module 32P connector.
  1. Reconnect the ABS modulator-control unit 25P connector.

  1. Measure the resistance between ECM/PCM connector terminals A3 and A4.
Is there about 2.34−2.86 kΩ?
YES -
Go to Step 21 .
NO -
  1. Disconnect the ABS modulator-control unit 46P connector (with ABS) or the gauge control module 32P connector (without ABS).
  1. Reconnect EPS control unit connector C (16P).

  1. Measure the resistance between ECM/PCM connector terminals A3 and A4.
Is there about 2.34−2.86 kΩ?
YES -
Go to Step 24 .
NO -
  1. Disconnect EPS control unit connector C (16P).
  1. Reconnect SRS unit connector A (39P).

  1. Measure the resistance between ECM/PCM connector terminals A3 and A4.
Is there about 2.34−2.86 kΩ?
YES -
Update the ECM/PCM if it does not have the latest software, or substitute a known-good ECM/PCM, then recheck. If the symptom/indication goes away with a known-good ECM/PCM, replace the original ECM/PCM.
NO -
  1. Disconnect these connectors:

  1. Check for continuity between ECM/PCM connector terminal A3 and body ground.
Is there continuity?
YES -
Repair short in the wire between ECM/PCM terminals A3 and the gauge control module, the ABS modulator-control unit, the EPS control unit, the SRS unit, or the DLC.■
NO -
Go to Step 29 .

  1. Check for continuity between ECM/PCM connector terminal A4 and body ground.
Is there continuity?
YES -
Repair short in the wire between ECM/PCM terminals A4 and the gauge control module, the ABS modulator-control unit, the EPS control unit, the SRS unit, or the DLC.■
NO -
Go to Step 30 .
  1. Reconnect all connectors.
  1. Disconnect the gauge control module 32P connector.
  1. Turn the ignition switch to ON (II), and read the HDS.
Does the HDS identify the vehicle?
YES -
NO -
  1. Turn the ignition switch to LOCK (0).
  1. Reconnect the gauge control module 32P connector.
  1. Disconnect the ABS modulator-control unit 25P connector.
  1. Turn the ignition switch to ON (II), and read the HDS.
Does the HDS identify the vehicle?
YES -
NO -
Go to Step 38 .
  1. Turn the ignition switch to LOCK (0).
  1. Reconnect the ABS modulator-control unit 25P connector (with ABS) or the gauge control module 32P connector (without ABS).
  1. Disconnect EPS control unit connector C (16P).
  1. Turn the ignition switch to ON (II), and read the HDS.
Does the HDS identify the vehicle?
YES -
NO -
Go to Step 42 .
  1. Turn the ignition switch to LOCK (0).
  1. Reconnect EPS control unit connector D (28P).
  1. Disconnect SRS unit connector A (39P).
  1. Turn the ignition switch to ON (II), and read the HDS.
Does the HDS identify the vehicle?
YES -
NO -
Update the ECM/PCM if it does not have the latest software, or substitute a known-good ECM/PCM, then recheck. If the symptom/indication goes away with a known-good ECM/PCM, replace the original ECM/PCM.