CRUISE CONTROL SYSTEM (DIAGNOSTICS) > Diagnostic Procedure with Diagnostic Trouble Code (DTC)

DTC 12

Detected when brake pedal is depressed or malfunction related to stop light & brake switch occurs.

TROUBLE SYMPTOM:

• Cruise control cannot be set.

• Cruise control cannot be released.

WIRING DIAGRAM:

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1.CHECK STOP LIGHT & BRAKE SWITCH CIRCUITS.

1) Turn the ignition switch to OFF.

2) Disconnect the stop light & brake switch harness connector.

3) Turn the ignition switch to ON.

4) Measure the voltage between harness connector terminal and chassis ground.

Connector & terminal

(B65) No. 1 (+) — Chassis ground (−):

Is the voltage 10 V or more?

• Check fuse No. 8 (in fuse & relay box).

• Check for open or short circuit in the harness between stop light & brake switch and fuse & relay box.

2.CHECK STOP LIGHT & BRAKE SWITCH CIRCUITS.

Measure the voltage between harness connector terminal and chassis ground.

Connector & terminal

(B65) No. 3 (+) — Chassis ground (−):

Is the voltage 10 V or more?

• Check fuse No. 4 (in fuse & relay box).

• Check for open or short circuit in the harness between stop light & brake switch and fuse & relay box.

3.CHECK STOP LIGHT & BRAKE SWITCH CIRCUITS.

1) Turn the ignition switch to OFF.

2) Disconnect the harness connector of ECM.

3) Measure the resistance between ECM harness connector terminal and stop light & brake switch harness connector terminal.

Connector & terminal

(B135) No. 28 — (B65) No. 4:

(B135) No. 20 — (B65) No. 2:

Is the resistance less than 10 Ω?

Repair the harness.

4.CHECK STOP LIGHT & BRAKE SWITCH.

Remove and check the stop light & brake switch.

Are the stop light switch and brake switch OK?

Replace the ECM.

Replace the stoplight & brake switch.