Inspection Procedure

1. Check that the stop light comes on when the brake pedal is depressed, and turns off when the brake pedal is released.

NO: INSPECT STOP LIGHT CIRCUIT 

YES: GO TO NEXT STEP 

1. See input signal check (See HOW TO TROUBLESHOOT ECU CONTROLLED SYSTEMS ).
2. Check the indicator light when the brake pedal is depressed.

   OK: The indicator light goes off when the brake pedal is depressed. 

Fig 1: Checking Input Signal Blinking Pattern
Courtesy of © TOYOTA, LICENSE AGREEMENT TMS1002

OK: PROCEED TO NEXT CIRCUIT INSPECTION SHOWN IN  PROBLEM SYMPTOMS TABLE  

NG: GO TO NEXT STEP 

1. Remove the cruise control ECU assembly with connectors still connected.
2. Turn the ignition switch to ON.
3. Measure voltage between terminal 3 (STP-) of cruise control ECU assembly connector and body ground, when the brake pedal is depressed and released.

   OK 

   TERMINAL VOLTAGE (STP-)
   
   

   Brake Pedal	Voltage
   Depressed	10 to 16 V
   Released	Below 1 V

   Fig 2: Inspecting Terminal Voltage (STP-)

   Courtesy of © TOYOTA, LICENSE AGREEMENT TMS1002

NG: PROCEED TO NEXT CIRCUIT INSPECTION SHOWN IN  PROBLEM SYMPTOMS TABLE  

OK: GO TO NEXT STEP 

1. Check for open and short circuit in harness and connector between cruise control ECU assembly and stop light switch assembly (See HOW TO TROUBLESHOOT ECU CONTROLLED SYSTEMS ).

NG: REPAIR OR REPLACE HARNESS OR CONNECTOR 

OK: CHECK AND REPLACE CRUISE CONTROL ECU ASSEMBLY