3.
Has a problem been found?
▶ Repair as necessary and then go to "Verification Of Vehicle Repair" procedure.
▶ Go to "Signal Circuit Inspection" procedure.
The HECU send requirement data, such as Torque reduction, the number of fuel cut cylinders, and ESP control requests, to the Engine PCM(ECM ＆ TCM) through CAN bus line. The Engine PCM(ECM) performs fuel cut functions according to requests from the HECU and retards ignition timing by torque reduction requests. The PCM(TCM) maintains current gear positions during ESP control time, in order not to increase power which causes a Kickdown shift.
The HECU checks the CAN communcation lines for normal ESP control, and sets this code if a PCM(ECM) message is not received within predefined time.
Item | Detecting Condition | Possible cause |
DTC Strategy | ● CAN massage monitoring | ● Faulty PCM(ECM) ● Faulty HECU |
Monitoring Period | ● Continuous | |
Enable Conditions | ● Faults are detected if PCM(ECM) message was not received on time by the CAN controller of HECU. | |
Fail Safe | ● Inhibit the ESP control and allow the ABS/EBD control. |
Many malfunctions in the electrical system are caused by poor harness(es) and terminal condition. Faults can also be caused by interference from other electrical systems, and mechanical or chemical damage.
Thoroughly check connectors for looseness, poor connection, bending, corrosion, contamination, deterioration, or damage.
Has a problem been found?
▶ Repair as necessary and then go to "Verification Of Vehicle Repair" procedure.
▶ Go to "Signal Circuit Inspection" procedure.
Ignition "OFF" ＆ Engine "OFF".
Disconnect HECU and PCM connector.
Measure resistance between the terminal "14, 35" of the HECU harness connector and the terminal "77, 78" of the PCM harness connector.
Specification : Approx. 0Ω
Is the measured resistance within specifications?
▶ Go to "Component inspection" procedure.
▶ Check for open between the terminal "14, 35" of the HECU harness connector and the terminal "77, 78" of the PCM harness connector. Repair as necessary and then go to "Verification of vehicle Repair" procedure.
Ignition "OFF".
Ignition "ON".
Connect scantool and select "Diagnostic Trouble Codes (DTCs)" mode.
Using a scantool, Clear DTC.
Select "Diagnostic Trouble Codes(DTCs)" mode again.
Are any DTCs present?
▶ Substitute with a known-good PCM(ECM) and check for proper operation. If problem is corrected, replace PCM(ECM) and then go to "Verification Of Vehicle Repair" procedure.If NG, replace HECU and then go to "Verification Of Vehicle Repair" procedure.
▶ Fault is intermittent caused by faulty HECU or was repaired and HECU memory was not cleared. go to "Verification Of Vehicle Repair" procedure.
After a repair, it is essential to verify that the fault has been corrected.
Connect scantool and select "Diagnostic Trouble Codes (DTCs)" mode
Using a scantool, Clear DTC.
Operate the vehicle within DTC Detecting Condition in General Information
Are any DTCs present?
▶ Go to the applicable troubleshooting procedure.
▶ System performing to specification at this time.
