Test No. 7: Stoplight Switch Circuit

Check stoplights. If stoplight operation is okay, go to step 4). If stoplights do not operate correctly, check STOP fuse and replace if necessary. If fuse is okay, go to next step.
Disconnect stoplight switch connector. See Figure. Depress brake pedal (switch pin free) and ensure continuity exists between stoplight switch terminal No. 1 (Green/White wire) and terminal No. 2 (Red/White wire).
Release brake pedal (switch pin pushed in) and ensure continuity exists between stoplight switch terminal No. 3 (Red/Yellow wire) and terminal No. 4 (Green/Black wire). If continuity is not as specified, replace stoplight switch. If continuity is as specified, check harness and connectors in stoplight circuit. Repair or replace as necessary.
Perform CANCEL SWITCHES test under CRUISE CONTROL FUNCTION TEST under TROUBLE SHOOTING. If stoplight input signal is as specified, go to next trouble code displayed or appropriate symptom under TROUBLE SHOOTING BY SYMPTOM under TROUBLE SHOOTING. If input signal is not as specified, remove CC ECU with connector connected. See Figure. Turn ignition switch to ON position.
Using voltmeter positive lead, backprobe CC ECU connector C15 terminal No. 16/STP- (Green/White wire) and ensure battery voltage exists between CC ECU connector C15 and ground with brake pedal depressed. Ensure less than one volt exists between terminal No. 16/STP- (Green/White wire) and ground with brake pedal released. If voltage is not as specified, go to next step. If voltage is as specified, go to test for next trouble code displayed or appropriate symptom under TROUBLE SHOOTING BY SYMPTOM under TROUBLE SHOOTING.
Check for open in harness and connectors between CC ECU and stoplight switch. Repair or replace as necessary. If harness and connectors are okay, check CC ECU. See PIN VOLTAGE TESTS . If found to be defective, replace CC ECU and retest system.