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DTC Troubleshooting: U0101

DTC U0101:
 F-CAN Malfunction (ECM-TCM)
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. Clear the DTC with the HDS.
  1. Check for Temporary DTCs or DTCs in the DTCs MENU with the HDS.
Is DTC U0101 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 gauge control module, the TCM, and the ECM.■
  1. Turn the ignition switch to LOCK (0).
  1. Check the No. 60 AMT (40 A) fuse in the under-dash fuse/relay box.
Is the fuse OK?
YES -
Go to Step 6 .
NO -
Repair short in the wire between the No. 60 AMT +B (40 A) fuse and the TCM. Also replace the No. 60 AMT +B (40 A) fuse, then go to Step 19 .
  1. Check for poor connections at TCM connector A (37P).
Are the connections OK?
YES -
Go to Step 8 .
NO -
Repair the poor connections or loose terminals at TCM connector A (37P), then go to Step 19 .
  1. Reconnect the engine compartment wire harness 10P connector; LHD model, RHD model.
  1. Turn the ignition switch to ON (II).
  1. Measure the voltage between TCM connector A (37P) terminal No. 28 and body ground.
Is there battery voltage?
YES -
Go to Step 13 .
NO -
Repair open in the wire between the No. 60 AMT (40 A) fuse and the TCM, then go to Step 19 .
  1. Turn the ignition switch to LOCK (0).

  1. Check for continuity between TCM connector A (37P) terminal No. 29 and body ground.
Is there continuity?
YES -
Go to Step 15 .
NO -
Repair open in the wire between the TCM and body ground (G151), then go to Step 19 .
  1. Jump the SCS line with the HDS.
  1. Disconnect ECM connector A (49P).

  1. Check for continuity between ECM connector terminal A3 and TCM connector A (37P) terminal No. 33.
Is there continuity?
YES -
Go to Step 18 .
NO -
Repair open in the wire between the ECM (A3) and the TCM, then go to Step 19 .

  1. Check for continuity between ECM connector terminal A4 and TCM connector A (37P) terminal No. 31.
Is there continuity?
YES -
Update the TCM if it does not have the latest software, or substitute a known-good TCM, then go to Step 20 and recheck. If DTC U0101 is not indicated with a known-good TCM, replace the original TCM, then go to Step 20 .
NO -
Repair open in the wire between the ECM (A4) and the TCM, then go to Step 20 .
  1. Turn the ignition switch to LOCK (0).
  1. Reconnect all connectors and the battery.
  1. Turn the ignition switch to ON (II).
  1. Reset the ECM with the HDS.
  1. Check for Temporary DTCs or DTCs with the HDS.
Is DTC U0101 indicated?
YES -
Check for poor connections or loose terminals at the gauge control module, the TCM, and the ECM, then go to Step 1 .
NO -
Troubleshooting is complete. If any other Temporary DTCs or DTCs are indicated, go to the indicated DTC's troubleshooting.■