Manufacturer Code Charts: 85

Control System DTCs

TPMS DTC Troubleshooting: 85

DTC 85 : F-CAN Communication Failure

NOTE: Check for fuel and emissions systems DTCs with the HDS, and troubleshoot the ECM/PCM and F-CAN communication errors first How To Troubleshoot The Fuel And Emissions Systems.

1. Problem verification:

Problem verification
-1. Turn the ignition switch to ON (II).

-2. Clear the DTC with the HDS.

-3. Turn the ignition switch to LOCK (0), and then back to ON (II).

-4. Wait about 5 seconds.

-5. Check for DTCs with the HDS.

Is DTC 85 indicated?
-YES- The failure is duplicated. Go to step 2.
-NO- Intermittent failure, the system is OK at this time.

2. Determine possible failure area (TPMS control unit, F-CAN line):

Determine possible failure area (TPMS control unit, F-CAN line)
-1. Test-drive the vehicle.

Does the speedometer work?
-YES- There is a problem in the F-CAN line. Go to step 4.
-NO- There is a problem in the TPMS control unit. Go to step 3.

3. TPMS control unit check:

TPMS control unit check
-1. Turn the ignition switch to LOCK (0).

-2. Disconnect the following connector.





-3. Test-drive the vehicle.

Does the speedometer work?
-YES- Check for loose terminals and poor connections at the TPMS control unit. If necessary, substitute a known-good TPMS control unit Service and Repair, and recheck.
-NO- Turn the ignition switch to LOCK (0), and reconnect all connectors, then check and troubleshoot the fuel and emissions systems How To Troubleshoot The Fuel And Emissions Systems.

4. Open wire check (F_CAN-L, F_CAN-H lines) 1:

Open wire check (F_CAN-L, F_CAN-H lines) 1
-1. Turn the ignition switch to LOCK (0).

-2. Short the SCS line with the HDS.

-3. Disconnect the following connectors.





-4. Check for continuity between test points 1 and 2.














Is there continuity?
-YES- The F_CAN-L, F_CAN-H wires are OK. Check for loose terminals and poor connections at the TPMS control unit and G501. If necessary, substitute a known-good TPMS control unit Service and Repair, and recheck.
-NO- Repair an open in the wire between the TPMS control unit and the ECM/PCM.