F-CAN Circuit Troubleshooting - PGM-FI System
NOTE: Information marked with an asterisk ( * ) applies to the CANL line.
  1. Turn the ignition switch OFF.
  1. Jump the SCS line with the HDS.
  1. Disconnect ECM connector A (44P), then disconnect the HDS.
  1. Measure resistance between ECM connector terminals A36 and A37.
Is there about 108−132 Ω?
YES -
Go to Step 36 .
NO -
Go to Step 5 .
  1. Disconnect the engine compartment wire harness 14P connector for LHD model, 20P connector for RHD model.
  1. Check for continuity between ECM connector terminals A36 and A37.
Is there continuity?
YES -
Repair short in the wire between ECM terminals A36 and A37 * .■
NO -
Go to Step 11 .
  1. Connect ECM connector terminal A36 to body ground with a jumper wire.
  1. Check for continuity between gauge control module (tach) 36P connector terminal No. 1 and body ground.
Is there continuity?
YES -
Go to Step 13 .
NO -
Repair open in the wire between the ECM (A36) and the gauge control module (tach).■
  1. Check for continuity between VSA modulator-control unit 46P connector terminal No. 39 and body ground.
Is there continuity?
YES -
Go to Step 14 .
NO -
Repair open in the wire between the ECM (A36) and the VSA modulator-control unit.■
  1. Check for continuity between EPS control unit connector D (28P) terminal No. 1 and body ground.
Is there continuity?
YES -
Go to Step 15 .
NO -
Repair open in the wire between the ECM (A36) and the EPS control unit.■
  1. Check for continuity between SRS unit connector A (28P) terminal No. 11 and body ground.
Is there continuity?
YES -
Go to Step 16 .
NO -
Repair open in the wire between the ECM (A36) and the SRS unit.■
  1. Remove the jumper wire from ECM connector A (44P).
  1. Connect ECM connector terminal A37 to body ground with a jumper wire.
  1. Check for continuity between gauge control module (tach) 36P connector terminal No. 19 and body ground.
Is there continuity?
YES -
Go to Step 19 .
NO -
Repair open in the wire between the ECM (A37) and the gauge control module (tach).■
  1. Check for continuity between VSA modulator-control unit 46P connector terminal No. 38 and body ground.
Is there continuity?
YES -
Go to Step 20 .
NO -
Repair open in the wire between the ECM (A37) and the VSA modulator-control unit.■
  1. Check for continuity between EPS control unit connector D (28P) terminal No. 15 and body ground.
Is there continuity?
YES -
Go to Step 21 .
NO -
Repair open in the wire between the ECM (A37) and the EPS control unit.■
  1. Check for continuity between SRS unit connector A (28P) terminal No. 12 and body ground.
Is there continuity?
YES -
Go to Step 22 .
NO -
Repair open in the wire between the ECM (A37) and the SRS unit.■
  1. Reconnect the gauge control module (tach) 36P connector.
  1. Measure resistance between ECM connector terminals A36 and A37.
Is there about 2.34−2.86 kΩ?
YES -
Go to Step 24 .
NO -
  1. Disconnect the gauge control module (tach) 36P connector.
  1. Reconnect the VSA modulator-control unit 46P connector.
  1. Measure resistance between ECM connector terminals A36 and A37.
Is there about 108−132 Ω?
YES -
Go to Step 27 .
NO -
  1. Disconnect the VSA modulator-control unit 46P connector.
  1. Reconnect the yaw rate-lateral acceleration sensor 4P connector.
  1. Measure resistance between ECM connector terminals A36 and A37.
Is there continuity?
YES -
NO -
Go to Step 30 .
  1. Reconnect EPS control unit connector D (28P).
  1. Measure resistance between ECM connector terminals A36 and A37.
Is there about 2.34−2.86 kΩ?
YES -
Go to Step 33 .
NO -
  1. Disconnect EPS control unit connector D (28P).
  1. Reconnect SRS unit connector A (28P).
  1. Measure resistance between ECM connector terminals A36 and A37.
Is there about 2.34−2.86 kΩ?
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 -
  1. Check for continuity between ECM connector terminal A36 and body ground.
Is there continuity?
YES -
Repair short in the wire between ECM terminal A36 and the gauge control module (tach), the VSA modulator-control unit, the yaw rate-lateral acceleration sensor, the EPS control unit, the SRS unit, or the DLC.■
NO -
Go to Step 41 .
  1. Check for continuity between ECM connector terminal A37 and body ground.
Is there continuity?
YES -
Repair short in the wire between ECM terminal A37 and the gauge control module (tach), the VSA modulator-control unit, the yaw rate-lateral acceleration sensor, the EPS control unit, the SRS unit, or the DLC.■
NO -
Go to Step 42 .
  1. Reconnect all connectors.
  1. Disconnect the gauge control module (tach) 36P connector.
  1. Turn the ignition switch ON (II), and read the HDS.
Does the HDS identify the vehicle?
YES -
NO -
Go to Step 46 .
  1. Turn the ignition switch OFF.
  1. Reconnect the gauge control module (tach) 36P connector.
  1. Disconnect the VSA modulator-control unit 37P connector.
  1. Turn the ignition switch ON (II), and read the HDS.
Does the HDS identify the vehicle?
YES -
NO -
Go to Step 50 .
  1. Turn the ignition switch OFF.
  1. Reconnect the VSA modulator-control unit 37P connector.
  1. Disconnect the yaw rate-lateral acceleration sensor 4P connector.
  1. Turn the ignition switch ON (II), and read the HDS.
Does the HDS identify the vehicle?
YES -
NO -
Go to Step 54 .
  1. Turn the ignition switch OFF.
  1. Disconnect EPS control unit connector D (28P).
  1. Turn the ignition switch ON (II), and read the HDS.
Does the HDS identify the vehicle?
YES -
NO -
Go to Step 58 .
  1. Turn the ignition switch OFF.
  1. Reconnect EPS control unit connector D (28P).
  1. Disconnect SRS unit connector A (28P).
  1. Turn the ignition switch ON (II), and read the HDS.
Does the HDS identify the vehicle?
YES -
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. ■