DTC B1312[11] Steering Switch Input Circuit Short to Ground (BCM)

1. Body control system check

Refer to "64.Body Control 10I.Troubleshooting(BCM) diagnostic system check-body controls".

2. Current DTC check

1) Connect the scan tool.

2) Turn OFF the ignition switch.

3) Turn ON the ignition switch.

4) Observe the DTC information with a scan tool. Is a DTC set?

Yes

=>Go to Cruise control switch inspection.

Go to Intermittent conditions of body control system.

Refer to "223.Body Control 36D.Symptom(BCM) intermittent conditions of body control system".

3. Cruise control switch inspection

1) Turn OFF the ignition switch.

2) Remove the cruise control switch.

Refer to "9.Body, Cab, Accessories 9C.Electrical Control, Entertainment cruise control steering wheel switch removal".

3) Disconnect the cruise control switch harness connector (B34).

Refer to "LHD Body Control" in the ETM (wiring diagram). (Open using the ETM viewer.).

Refer to "RHD Body Control (4JJ3 with DPD)" in the ETM (wiring diagram). (Open using the ETM viewer.).

Refer to "RHD Body Control (4JJ3 without DPD, RZ4E)" in the ETM (wiring diagram). (Open using the ETM viewer.).

4) Turn ON the ignition switch.

5) Observe the DTC information with a scan tool. Is DTC B1312[11] set?

Yes

=>Go to Inspection for short to ground in cruise control switch input circuit.

Replace the cruise control switch.

Refer to "9.Body, Cab, Accessories 9C.Electrical Control, Entertainment cruise control steering wheel switch removal".

Refer to "9.Body, Cab, Accessories 9C.Electrical Control, Entertainment cruise control steering wheel switch installation".

=>Go to Repair verification.

4. Inspection for short to ground in cruise control switch input circuit

1) Disconnect the BCM harness connector (B16).

2) Inspect the following cruise control switch input circuits for a short to ground. Is the result normal?

Between the BCM (pin 2 of B16) and the cruise control switch (pin 11 of B34) (RES switch, inter-vehicular switch, LKAS switch)

Between the BCM (pin 20 of B16) and the cruise control switch (pin 1 of B34) (CANCEL switch, MAIN switch, SET/- switch, SET/+ switch)

Refer to "LHD Body Control" in the ETM (wiring diagram). (Open using the ETM viewer.).

Refer to "RHD Body Control (4JJ3 with DPD)" in the ETM (wiring diagram). (Open using the ETM viewer.).

Refer to "RHD Body Control (4JJ3 without DPD, RZ4E)" in the ETM (wiring diagram). (Open using the ETM viewer.).

3) Is the result normal?

Yes

=>Go to BCM replacement.

Repair the circuit as necessary.

=>Go to Repair verification.

5. BCM replacement

Note

Perform programming after replacing the BCM.

Refer to "9.Body, Cab, Accessories 9Z.Body, Cab, Accessories Electrical Control BCM removal".

Refer to "9.Body, Cab, Accessories 9Z.Body, Cab, Accessories Electrical Control BCM installation".

Refer to "9.Body, Cab, Accessories 9Z.Body, Cab, Accessories Electrical Control BCM setting".

Procedure completion

=>Go to Repair verification.

6. Repair verification

1) Clear the DTC with a scan tool.

2) Turn OFF the ignition switch for 30 seconds or more.

3) Turn ON the ignition switch.

4) Observe the DTC information with a scan tool.