DTC U0122: F-CAN Malfunction (ECM/PCM-VSA Modulator-Control Unit)
- Turn the ignition switch to ON (II).
- Clear the DTC with the HDS.
- Check for Temporary DTCs or DTCs with the HDS.
Is DTC U0122 indicated?
YES -Go to step 4.
NO -Intermittent failure, the system is OK at this time. Check for poor connections or loose terminals at the VSA modulator-control unit and the ECM/PCM.
- Check for a DTC in the DTCs MENU with the HDS.
Is VSA DTC 86 indicated?
YES -Go to step 5.
NO -Go to step 13.
- Turn the ignition switch to LOCK (0).
- Jump the SCS line with the HDS.
- Disconnect the VSA modulator-control unit 47P connector (see REMOVAL ).
- Disconnect ECM/PCM connector E (31P).
- Connect VSA modulator-control unit 47P connector terminal No. 11 to body ground with a jumper wire.
- Check for continuity between ECM/PCM connector terminal El 1 and body ground.
Courtesy of AMERICAN HONDA MOTOR CO., INC.
Is there continuity?
YES -Go to step 11.
NO -Repair open in the wire between the ECM/PCM (E11) and the VSA modulator-control unit (No. 11), then go to step 20.
- Connect VSA modulator-control unit 47P connector terminal No. 15 to body ground with a jumper wire.
- Check for continuity between ECM/PCM connector terminal E24 and body ground.
Courtesy of AMERICAN HONDA MOTOR CO., INC.
Is there continuity?
YES -Substitute a known-good VSA modulator-control unit, then go to step 20 and recheck. If DTC U0122 is not indicated, replace the original VSA modulator-control unit, then go to step 20.
NO -Repair open in the wire between the ECM/PCM (E24) and the VSA modulator-control unit (No. 15), then go to step 20.
- Turn the ignition switch to LOCK (0).
- Check for poor connections or loose terminals at the VSA modulator-control unit 47P connector.
Are the connections and terminals OK?
YES -Go to step 15.
NO -Repair the connections or terminals, then go to step 20.
- Disconnect the VSA modulator-control unit 47P connector.
- Turn the ignition switch to ON (II).
- Measure the voltage between VSA modulator-control unit 47P connector terminal No. 4 and body ground.Fig 5: Measuring Voltage Between VSA Modulator-Control Unit 47P Connector Terminal No. 4 And Body Ground
Courtesy of AMERICAN HONDA MOTOR CO., INC.
Is there battery voltage?
YES -Go to step 18.
NO -Check the No. 4 ACG (10 A) fuse in the under-dash fuse/relay box. If the fuse is OK, repair open in the wire between the No. 4 ACG (10 A) fuse and the VSA modulator-control unit, then go to step 20.
- Turn the ignition switch to LOCK (0).
- Check for continuity between VSA modulator-control unit 47P connector terminal No. 16 and body ground.Fig 6: Checking Continuity Between VSA Modulator-Control Unit 47P Connector Terminal No. 16 And Body Ground
Courtesy of AMERICAN HONDA MOTOR CO., INC.
Is there continuity?
YES -Substitute a known-good VSA modulator-control unit (see VSA MODULATOR-CONTROL UNIT REMOVAL AND INSTALLATION ), then go to step 20 and recheck. If U0122 is not indicated, replace the original VSA modulator-control unit (see VSA MODULATOR-CONTROL UNIT REMOVAL AND INSTALLATION ), then go to step 20.
NO -Repair open in the wire between the VSA modulator-control unit and G202, then go to step 20.
- Reconnect all connectors.
- Turn the ignition switch to ON (II).
- Reset the ECM/PCM with the HDS.
- Do the ECM/PCM idle learn procedure (see ECM/PCM IDLE LEARN PROCEDURE ).
- Check for Temporary DTCs or DTCs with the HDS.
Is DTC U0122 indicated?
YES -Check for poor connections or loose terminals at the ECM/PCM and the VSA modulator-control unit, then go to step 1.
NO -Troubleshooting is complete. If any other Temporary DTCs or DTCs are indicated, go to the indicated DTCs troubleshooting.