DTC Troubleshooting: U0104 (126)
DTC U0104:
 F-CAN Malfunction (ECM/PCM-ACC Unit)
NOTE: Before you troubleshoot, record all freeze data and any on-board snapshot, and review the general troubleshooting information.
  1. Turn the ignition switch to ON (II).
  1. Check for Temporary DTCs or DTCs with the HDS.
Are DTC U0029 and U0104 indicated at the same time?
YES -
Go to troubleshooting for DTC U0029. ■
NO -
Go to Step 3 .
  1. Clear the DTC with the HDS.
  1. Check for Temporary DTCs or DTCs with the HDS.
Is DTC U0104 indicated?
YES -
Go to Step 5 .
NO -
Intermittent failure, the system is OK at this time. Check for poor connections or loose terminals at the gauge control module, the ACC unit, and the ECM/PCM.■
  1. Check for communication to the driving support system with the HDS.
Does the HDS communicate with the ACC unit?
YES -
Go to Step 6 .
NO -
Go to the DLC circuit troubleshooting. ■
  1. Turn the ignition switch to LOCK (0).
  1. Jump the SCS line with the HDS.
  1. Disconnect the ACC unit 20P connector.
  1. Disconnect ECM/PCM connector A (49P).
  1. Connect ACC unit 20P connector terminal No. 10 to body ground with a jumper wire.