C1612

C1612

Component Location:

General Description
The HECU send requirement data, such as Torque reduction, the number of fuel cut cylinders, and ESC control requests, to the Engine ECU & TCU through CAN bus line.
The Engine ECU performs fuel cut functions according to requests from the HECU and retards ignition timing by torque reduction requests.
The TCU maintains current gear positions during ESC control time, in order not to increase power which causes a Kickdown shift.

DTC Description
The HECU checks the CAN communication lines for normal ESC control, and sets this code if an TCM message is not received within predefined time.

DTC Detecting Condition:

Component Inspection
1. Ignition "OFF".
2. Engine "ON".
3. Does warning lamp remain On?

YES - Thoroughly check connectors for looseness, poor connection, bending, corrosion, contamination, deterioration, or damage. Repair as necessary and then go to "Verification of vehicle Repair" procedure.
If OK, Substitute with a known-good TCU and check for proper operation. If problem is corrected, replace TCU and then go to "Verification of Vehicle Repair" procedure.
If NG, replace HECU and then go to "Verification of Vehicle Repair" procedure.

NO - Fault is intermittent caused by faulty HECU or was repaired and HECU memory was not cleared, go to "Verification of Vehicle Repair" procedure.

Verification of Vehicle Repair
After a repair, it is essential to verify that the fault has been corrected.
1. Connect scantool and select "Diagnostic Trouble Codes (DTCs)" mode
2. Using a scantool, Clear DTC.
3. Operate the vehicle within DTC Detecting Condition in General Information.
4. Are any DTCs present?

YES - Go to the applicable troubleshooting procedure.

NO - System performing to specification at this time.