CODE No. U0126 SAS CAN timeout

caution

If diagnosis code No. U0126 is set in the BSW-ECU (slave), always diagnose the CAN bus line.
Before replacing the ECU, ensure that the power supply circuit, the earth circuit and the communication circuit are normal.

OPERATION

The BSW-ECU (slave) communicates with the steering wheel sensor via the gateway-ECU and the BSW-ECU (master) over CAN bus lines.

CHECK CONDITION

Ignition switch is in the ON position.

DIAGNOSTIC FUNCTION AND JUDGEMENT CRITERIA

If the BSW-ECU (slave) cannot receive any signal from the steering wheel sensor for at least 2.5 seconds, the ECU sets diagnosis code No. U0126.

PROBABLE CAUSES

Power supply circuit to the steering wheel sensor fails
Malfunction of the steering wheel sensor
Power supply to the gateway-ECU fails
Malfunction of the gateway-ECU
Malfunction of the BSW-ECU (master/slave)
Malfunction of the CAN bus
Malfunction of the local CAN bus

DIAGNOSIS PROCEDURE

STEP 1. Check whether the BSW-ECU sets a diagnosis code.

Check whether diagnosis codes No. C2332 and/or U0126 are set in the BSW-ECU (master).

Q. Is the diagnosis code set?

YES (Only No. C2332 is set or both codes are set) : Follow diagnosis code procedure No. C2332 for the BSW-ECU (master) (Refer to

).

YES (Only No. U0126 is set) : Follow diagnosis code procedure No. U0126 for the BSW-ECU (master) (Refer to

Go to Step 2

STEP 2. Check whether the diagnosis code is set again.

Check again if the diagnosis code is set in the BSW-ECU (slave).

(1)Erase the diagnosis code.

(2)Turn the ignition switch from the LOCK (OFF) position to the ON position.

(3)Check if the diagnosis code is set.

Q. Is the diagnosis code set?

Replace the BSW-ECU (slave).

Intermittent malfunction is suspected (Refer to GROUP 00 - How to Use Troubleshooting/Inspection Service Points - How to cope with Intermittent Malfunction).