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Test No. 1: Set Function Not Occurring Or Cancel Function Occurring (Normal DTC Output On Input Signal Check)

WARNING: This page is about a different car, the 2002 Toyota Avalon. However, it is still accessible from the selected car via links, so may be relevant.
  1. Check vehicle speed sensor. See DTC 21: VEHICLE SPEED SENSOR CIRCUIT  test under DIAGNOSTIC TESTS. If vehicle speed sensor circuit is okay, go to next step.
  2. Check cruise control switch. See DTC 32: CRUISE CONTROL SWITCH CIRCUIT  test under DIAGNOSTIC TESTS. If cruise control switch circuit is okay, go to next step.
  3. Check stoplight operation when brake pedal is depressed. If stoplight operation is okay, go to next step. If stoplights do not operate correctly, repair stoplights as necessary. See EXTERIOR LIGHTS in SYSTEM WIRING DIAGRAMS article.
  4. Perform stoplight switch input signal check. See STEP 3 of Cruise Control Input Signal Check. See Figure. If stoplight switch input signal is not as specified, go to next step. If stoplight switch input signal is as specified, no problem is indicated at this time. Fault may be intermittent, go to step  7.
  5. Turn ignition off. Remove cruise control ECU with connector attached. See Figure. Turn ignition on. Using a DVOM, measure voltage by backprobing between cruise control ECU 16-pin electrical harness connector terminal No. 2 (Green/White wire) and good body ground point. See Figure. With brake pedal depressed, battery voltage should exist. With brake pedal released, voltage should be less than one volt. If voltage is not as specified, go to next step. If voltage is as specified, no problem is indicated at this time. Fault may be intermittent, go to step  7.
  6. Turn ignition off. Disconnect cruise control ECU 16-pin electrical harness connector and stoplight switch 4-pin Blue electrical harness connector. Using a DVOM, check for open circuit in Green/White wire between cruise control ECU 16-pin electrical harness connector terminal No. 2 and stoplight switch 4-pin Blue electrical harness connector terminal No. 1. See Figure. If wires, harnesses and connectors are okay, go to step  13. If wires, harnesses and connectors are not okay, repair fault as required. See CRUISE CONTROL in SYSTEM WIRING DIAGRAMS article. After repairs, perform confirmation test. See CONFIRMATION TEST .
  7. Ensure starter operates normally and engine starts. Check for starting system problems and repair as necessary. See STARTERS - EXCEPT PRIUS article in ENGINE. If starter is okay, go to next step.
  8. Perform park/neutral position switch input signal check. See STEP 3 of Cruise Control Input Signal Check. See Figure. If park/neutral position switch input signal is not as specified, go to next step. If input signals are as specified, no problem is indicated at this time. Fault may be intermittent, go to step  11.
  9. Turn ignition off. Remove cruise control ECU with connector attached. See Figure. Turn ignition on. Using a DVOM, measure voltage by backprobing between cruise control ECU 16-pin electrical harness connector terminal No. 3 (Yellow/Red wire) and good body ground point. See Figure. With gear shift lever in Drive, battery voltage should exist. With gear shift lever in any position other than Drive, voltage should be less than one volt. If voltage is not as specified, go to next step. If voltage is as specified, no problem is indicated at this time. Fault may be intermittent, go to step  11.
  10. Turn ignition off. Disconnect cruise control ECU 16-pin electrical harness connector and park/neutral position switch 10-pin Gray electrical harness connector. Using a DVOM, check for open and short circuit conditions in Yellow/Red wire between cruise control ECU 16-pin electrical harness connector terminal No. 3 and park/neutral position switch 10-pin Gray electrical harness connector terminal No. 10. See Figure. If wires, harnesses and connectors are okay, go to step  13. If wires, harnesses and connectors are not okay, repair fault as required. See CRUISE CONTROL in SYSTEM WIRING DIAGRAMS article. After repairs, perform confirmation test. See CONFIRMATION TEST .
  11. Check cruise control actuator. See DTC 11: SHORT IN CRUISE CONTROL ACTUATOR CIRCUIT OR DTC 15: OPEN IN CRUISE CONTROL ACTUATOR CIRCUIT  test under DIAGNOSTIC TESTS. If cruise control actuator is okay, go to next step.
  12. Check cruise control actuator control cable adjustment. See CRUISE CONTROL ACTUATOR CONTROL CABLE  under ADJUSTMENTS. If cruise control actuator control cable adjustment is okay, go to next step. If cruise control actuator control cable adjustment is not okay, adjust as required. After repairs, perform confirmation test. See CONFIRMATION TEST .
  13. Turn ignition off. Disconnect cruise control ECU 16-pin electrical harness connector. Using DVOM, check cruise control ECU ground circuit. See CRUISE CONTROL in SYSTEM WIRING DIAGRAMS article. If ground circuit is faulty, repair and retest system. If ground circuit is okay, substitute original cruise control ECU with a known-good unit and recheck system operation. If system operates properly, original cruise control ECU was defective. If system still does not operate properly, perform cruise control ECU pin voltage check. See PIN VOLTAGE TESTS . Check wiring harness and electrical connectors for an intermittent problem. Repair wiring harnesses or connectors as necessary. See CRUISE CONTROL in SYSTEM WIRING DIAGRAMS article. If voltage values, harnesses and connectors are okay, replace cruise control ECU. See CRUISE CONTROL ELECTRONIC CONTROL UNIT  under REMOVAL & INSTALLATION. After repairs, perform confirmation test. See CONFIRMATION TEST .
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