Code No. U0151: SRS CAN time-out

caution

If diagnosis code No.U0151 is set in the heater control panel or A/C control panel, diagnose the CAN main bus line.

caution

Whenever the ECU is replaced, ensure that the communication circuit is normal.

TROUBLE JUDGMENT

The heater control panel or A/C control panel receives air conditioner control-related signals from the SRS-ECU via the CAN bus lines. If the ECU cannot receive any of the air conditioner control-related signals from the SRS-ECU, diagnosis code U0151 will be stored.

COMMENTS ON TROUBLE SYMPTOM

Current trouble

Connector(s) or wiring harness in the CAN bus lines between the SRS-ECU and the heater control panel or A/C control panel, the power supply system to the SRS-ECU, the SRS-ECU itself, or the heater control panel or A/C control panel may be defective.

Past trouble

Carry out diagnosis with particular emphasis on connector(s) or wiring harness in the CAN bus lines between the SRS-ECU and the heater control panel or A/C control panel, and the power supply system to the SRS-ECU. For diagnosis procedures, refer to "How to treat past trouble" (Refer to GROUP 00 - How to Treat Past Trouble

note

For a past trouble, you can not find it by the M.U.T.-III CAN bus diagnostics even if there is any failure in CAN bus lines. In this case, refer to GROUP 00, How to Cope with Intermittent Malfunction

and check the CAN bus lines. You can narrow down the possible cause of the trouble by referring to the diagnosis code, which is set regarding the CAN communication-linked ECUs (Refer to GROUP 54C - CAN Bus Line Diagnostic Flow

caution

If the ignition switch is turned to the ON position without starting the engine, the diagnosis code U0151 (past trouble) may be set to the heater control panel or A/C control panel after three minutes.

PROBABLE CAUSES

Damaged harness wires and connectors
Malfunction of SRS-ECU
Malfunction of the heater control panel or A/C control panel

DIAGNOSIS PROCEDURE

STEP 1. M.U.T.-III CAN bus diagnostics

Use the M.U.T.-III to diagnose the CAN bus lines.

Q. Is the check result normal?

	Go to Step 2

	Repair the CAN bus lines. (Refer to GROUP 54C, Troubleshooting ) On completion, go to Step 6.

STEP 2. M.U.T.-III other system diagnosis code

Check whether the SRS-related diagnosis code is set.

Q. Is the diagnosis code set?

	Diagnose the SRS-ECU. Refer to .

	Go to Step 3.

STEP 3. M.U.T.-III other system diagnosis code

Check if a diagnosis code, which relates to CAN communication-linked systems below, is set.

ETACS-ECU
U0151: SRS-ECU-related time-out diagnosis code

Q. Is the diagnosis code set?

	Go to Step 4.

	Go to Step 5.

STEP 4. Check whether the diagnosis code is reset.

Recheck if the diagnosis code is set.

(1)Erase the diagnosis code.

(2)Ignition switch: LOCK (OFF) to ON

(3)Check if the diagnosis code is set.

Q. Is the diagnosis code set?

	Replace the SRS-ECU, and then go to Step 6.

	A poor connection, open circuit or other intermittent malfunction in the CAN bus line between the SRS-ECU and the heater control panel or A/C control panel (Refer to GROUP 00 - How to Cope with Intermittent Malfunction ).

STEP 5. Check whether the diagnosis code is reset.

Recheck if the diagnosis code is set.

(1)Erase the diagnosis code.

(2)Ignition switch: LOCK (OFF) to ON

(3)Check if the diagnosis code is set.

Q. Is the diagnosis code set?

	Replace the heater control panel or A/C control panel, and then go to Step 6.

	A poor connection, open circuit or other intermittent malfunction in the CAN bus line between the SRS-ECU and the heater control panel or A/C control panel(Refer to GROUP 00 - How to Cope with Intermittent Malfunction ).

STEP 6. Check whether the diagnosis code is reset.

Recheck if the diagnosis code is set.

(1)Erase the diagnosis code.

(2)Ignition switch: LOCK (OFF) to ON

(3)Check if the diagnosis code is set.

Q. Is the diagnosis code set?

	Return to Step 1.

	The procedure is complete.