F-CAN Circuit Troubleshooting - PGM-FI System
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 connector A (49P), then disconnect the HDS.
  1. Measure the resistance between ECM connector terminals A3 and A4.
Is there about 88−111 Ω?
YES -
Go to Step 40 .
NO -
Go to Step 5 .
  1. Disconnect these connectors:
  1. Check for continuity between ECM connector terminals A3 and A4.
Is there continuity?
YES -
Repair short in the wire between ECM terminals A3 and A4 * .■
NO -
Go to Step 7 .
  1. Connect ECM connector terminal A3 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 9 .
NO -
Repair open in the wire between the ECM (A3) 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 10 .
NO -
Repair open in the wire between the ECM (A3) 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 11 .
NO -
Repair open in the wire between the ECM (A3) 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 -
NO -
Repair open in the wire between the ECM (A3) and the SRS unit.■
  1. Check for continuity between engine compartment wire harness 10P connector terminal No. 7 and body ground.
Is there continuity?
YES -
Go to Step 13 .
NO -
  • Repair open in the wire between the ECM (A3) and the clutch actuator wire harness.
  • Check the clutch actuator wire harness for an open.■
  1. Remove the jumper wire from ECM connector A (49P).
  1. Connect ECM connector terminal A4 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 16 .
NO -
Repair open in the wire between the ECM (A4) 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 17 .
NO -
Repair open in the wire between the ECM (A4) 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 18 .
NO -
Repair open in the wire between the ECM (A4) 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 -
NO -
Repair open in the wire between the ECM (A4) and the SRS unit.■
  1. Check for continuity between engine compartment wire harness 10P connector terminal No. 6 and body ground.
Is there continuity?
YES -
Go to Step 20 .
NO -
  • Repair open in the wire between the ECM (A4) and the clutch actuator wire harness.
  • Check the clutch actuator wire harness for an open.■
  1. Reconnect the gauge control module (tach) 36P connector.
  1. Measure the resistance between ECM connector terminals A3 and A4.
Is there about 2.34−2.86 kΩ?
YES -
Go to Step 22 .
NO -
  1. Disconnect the gauge control module (tach) 36P connector.
  1. Reconnect the VSA modulator-control unit 46P connector.
  1. Measure the resistance between ECM connector terminals A3 and A4.
Is there about 108−132 Ω?
YES -
Go to Step 25 .
NO -
  1. Disconnect the VSA modulator-control unit 46P connector.
  1. Reconnect the yaw rate-lateral acceleration sensor 4P connector.
  1. Measure the resistance between ECM connector terminals A3 and A4.
Is there continuity?
YES -
NO -
Go to Step 28 .
  1. Reconnect EPS control unit connector D (28P).
  1. Measure the resistance between ECM connector terminals A3 and A4.
Is there about 2.34−2.86 kΩ?
YES -
Go to Step 31 .
NO -
  1. Disconnect EPS control unit connector D (28P).
  1. Reconnect SRS unit connector A (28P).
  1. Measure the resistance between ECM connector terminals A3 and A4.
Is there about 2.34−2.86 kΩ?
YES -
NO -
  1. Disconnect SRS unit connector A (28P).
  1. Reconnect the engine compartment wire harness 10P connector.
  1. Measure the resistance between ECM connector terminals A3 and A4.
Is there about 2.34−2.86 kΩ?
YES -
Go to Step 37 .
NO -
  1. Disconnect the engine room wire harness 10P connector.
  1. Reconnect the gear shift control module 12P connector.
  1. Measure the resistance between ECM connector terminals A3 and A4.
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. Disconnect these connectors:
  1. Check for continuity between ECM connector terminal A3 and body ground.
Is there continuity?
YES -
Repair short in the wire between the ECM terminals A3 and the gauge control module (tach), the VSA modulator-control unit, the yaw rate-lateral acceleration sensor, the EPS control unit, the SRS unit, the TCM (with i-SHIFT system); or the DLC.■
NO -
Go to Step 42 .
  1. Check for continuity between ECM connector terminal A4 and body ground.
Is there continuity?
YES -
Repair short in the wire between the ECM terminals A4 and the gauge control module (tach), the VSA modulator-control unit, the yaw rate-lateral acceleration sensor, the EPS control unit, the SRS unit, the TCM (with i-SHIFT system); or the DLC.■
NO -
Go to Step 43 .
  1. Reconnect all connectors.
  1. Connect the HDS to the DLC.
  1. Disconnect the gauge control module (tach) 36P connector.
  1. Turn the ignition switch to ON (II), and read the HDS.
Does the HDS identify the vehicle?
YES -
NO -
Go to Step 47 .
  1. Turn the ignition switch to LOCK (0).
  1. Reconnect the gauge control module (tach) 36P connector.
  1. Disconnect the VSA modulator-control unit 37P connector.
  1. Turn the ignition switch to ON (II), and read the HDS.
Does the HDS identify the vehicle?
YES -
NO -
Go to Step 51 .
  1. Turn the ignition switch to LOCK (0).
  1. Reconnect the VSA modulator-control unit 37P connector.
  1. Disconnect the yaw rate-lateral acceleration sensor 4P connector.
  1. Turn the ignition switch to ON (II), and read the HDS.
Does the HDS identify the vehicle?
YES -
NO -
Go to Step 55 .
  1. Turn the ignition switch to LOCK (0).
  1. Disconnect EPS control unit connector D (28P).
  1. Turn the ignition switch to ON (II), and read the HDS.
Does the HDS identify the vehicle?
YES -
NO -
Go to Step 59 .
  1. Turn the ignition switch to LOCK (0).
  1. Reconnect EPS control unit connector D (28P).
  1. Disconnect SRS unit connector A (28P).
  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 SRS unit connector A (28P).
  1. Disconnect the engine compartment wire harness 10P connector.
  1. Turn the ignition switch to ON (II), and read the HDS.
Does the HDS identify the vehicle?
YES -
NO -
Go to Step 67 .
  1. Turn the ignition switch to LOCK (0).
  1. Reconnect the engine compartment wire harness 10P connector.
  1. Disconnect the gear shift control module 12P connector.
  1. Turn the ignition switch to 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. ■