LEMON Manuals: Even more car manuals for everyone: 1960-2025
Home >> Toyota >> 1993 >> Corolla LE >> Repair and Diagnosis >> Accessories & Equipment >> Cruise Control Systems >> Circuit Testing >> Test 7: Stoplight Switch Circuit
April 5, 2026: LEMON Manuals is launched! Read the announcement.

Test 7: Stoplight Switch Circuit

  1. Check stoplights. If stoplight operation is okay, go to step 7). If stoplights do not operate correctly, check STOP fuse and replace if necessary. If fuse is okay, go to step 4). If fuse continuously fails, go to next step.
  2. Remove CC ECU connector. If fuse does not fail, repair short in circuit between STOP fuse and stoplight switch connector terminal No. 2 (Red/White wire) or between STOP fuse and CC ECU connector terminal No. 1 (Red/White wire). If fuse does fail, go to next step.
  3. Replace fuse. Apply and hold brake pedal. If fuse is okay, replace CC ECU. If fuse fails, repair short in circuit between stoplight connector terminal No. 1 and brake light (Green/White wire) or between stoplight connector terminal No. 1 and CC ECU connector terminal No. 16.
  4. Remove connector from stoplight switch. Measure voltage between connector terminal No. 2 (Red/White wire) and ground. If battery voltage is not present, repair open circuit between stoplight switch terminal No. 2 and STOP fuse. If battery voltage is present, go to next step.
  5. Connect jumper wire between stoplight switch terminals No. 1 (Green/White wire) and No. 2 (Red/White wire). If brakelights do not light, repair open circuit between connector terminal No. 1 and ground. If brakelights light, go to next step.
  6. Remove stoplight connector. Depress brake pedal (switch pin free) and ensure continuity exists between stoplight switch terminals No. 1 (Green/White wire) and No. 2 (Red/White wire). Release brake pedal (switch pin pushed in) and ensure continuity exists between stoplight switch terminals No. 3 (Green/Black wire) and No. 4 (Red/Yellow wire). If continuity is not present, replace stoplight switch. If stop light switch is okay, install connector, remove CC ECU with connector connected and go to next step.
  7. Depress brake pedal. Using voltmeter positive lead, backprobe CC ECU connector terminal No. 1/STP+ (Red/White wire) and ensure battery voltage between CC ECU connector and ground. Using voltmeter positive lead, backprobe CC ECU connector terminal No. 16/STP- (Green/White wire) ensure battery voltage between CC ECU connector and ground. If battery voltage is not present, repair open circuit between stoplight switch terminal No. 2 (Red/White wire) and STOP fuse. If battery voltage is present, go to next step.
  8. Release brake pedal and repeat testing from step 7). Ensure battery voltage exists between CC ECU connector terminal No. 1/STP+ and ground. Ensure less than one volt exists between terminal No. 16/STP- and ground. If battery voltage is not as specified, repair open in harness circuit between CC ECU connector terminal No. 1/STP+ and stoplight switch terminal No. 2 or CC ECU terminal No. 16/STP- and stoplight switch terminal No. 1. If battery voltage is as specified, replace CC ECU and retest system.
scientia non olet · About LEMON Manuals