What this code means
U0151 may mean the gauge control module and SRS unit are not communicating normally on the F-CAN network.
What the vehicle may do
- The vehicle may show warning indicators.
- A scan tool may show communication-related behavior.
- The concern can be intermittent if the code does not reset after clearing.
Possible fault areas
- Possible loose or poor connector contact.
- Possible open or poor connection in the F-CAN wiring between the SRS unit and gauge control module.
- Possible gauge control module involvement if the F-CAN continuity check passes.
Diagnostic path
Set up the code
On this 2010 to 2015 Honda Civic with the 1.8 gas engine, U0151 means the gauge control module has lost communication with the SRS unit on the F-CAN side. In plain terms, the cluster and the airbag control unit may not be talking the way they should. The vehicle may show warning indicators, communication-related scan tool behavior, or an intermittent concern. The broad possible fault areas are the F-CAN wiring between the two modules, loose or poor connector contact, or the gauge control module side of the circuit. Before you focus on U0151, if there are any loss-of-communication codes for the ECM or PCM, handle those first. And if you are dealing with multiple codes at the same time, work through the multiple-code network diagnosis before narrowing this one down.
Verify the fault first
Start by verifying that U0151 is active after a clean reset. Clear the DTCs with the HDS. Turn the ignition switch to LOCK, position 0, and then back to ON, position II. Wait for at least 6 seconds, then check for DTCs again with the HDS. If U0151 comes back, continue to the F-CAN wire check. If U0151 does not come back, treat it as an intermittent failure. The system is OK at this time, so check for loose or poor connections instead of forcing a hard-fault diagnosis.
Check the F-CAN wires for an open
With the code confirmed, turn the ignition switch back to LOCK, position 0. Disconnect the gauge control module, tach, 32P connector, and disconnect SRS unit connector A, the 39P connector. Now check continuity on the two F-CAN circuits between those connectors. For F-CAN-H, check from gauge control module 32P connector terminal No. 19, WHT wire, to SRS unit connector A 39P terminal No. 20, WHT wire. For F-CAN-L, check from gauge control module 32P connector terminal No. 20, RED wire, to SRS unit connector A 39P terminal No. 21, RED wire.
Use the continuity result
Use the continuity result to split the diagnosis. If there is continuity on the F-CAN wire check, the diagnostic path points to replacing the gauge control module, tach. If there is not continuity, the fault is an open or poor connection in the F-CAN wires between the SRS unit and the gauge control module, tach. Stay with that result and correct the wiring or connection issue before moving on.
Verify and close
After the repair path is completed, keep verification separate from the circuit testing. Clear the DTCs, cycle the ignition from LOCK, position 0, back to ON, position II, wait for at least 6 seconds, and check again with the HDS to confirm U0151 stays gone. The takeaway is simple: prove the code first, check the two F-CAN wires between the cluster and SRS unit, and let the continuity result decide whether you are chasing wiring or the gauge control module. For more diagnostic training, visit stepdiagnostics.com.
Final check
This diagnosis often comes down to confirming the code, checking the F-CAN wiring path, and using the continuity result to separate a wiring fault from a module-side fault.
For more guided automotive diagnostics, visit STEP Diagnostics.
