DTC C1A05: Stop Light Switch Circuit [08/2013 - ]: Procedure

1. Check that the stop lights come on when the brake pedal is depressed, and go off when the brake pedal is released.

   OK

   Condition	Illumination Condition
   Brake pedal depressed	ON
   Brake pedal released	OFF

NG → GO TO LIGHTING SYSTEM (EXT). Refer to:  STOP LIGHT SWITCH 

OK: Go to next step 

1. Connect the Techstream to the DLC3.
2. Turn the power switch on (IG).
3. Turn the Techstream on.
4. Enter the following menus: Powertrain / Radar Cruise / Data List.
5. Check the Data List for proper functioning of the stop light switch assembly.
   RADAR CRUISE
   
   

   Tester Display	Measurement Item/Range	Normal Condition	Diagnostic Note
   Stop Light SW 1 (M CPU)	Stop light switch (Main-CPU) signal / ON or OFF	ON: Brake pedal depressed OFF: Brake pedal released	-
   Stop Light SW 1 (S CPU)	Stop light switch (Sub-CPU) signal / ON or OFF	ON: Brake pedal depressed OFF: Brake pedal released	-
   Stop Light SW 2 (M CPU)	Stop light switch (Main-CPU) signal / ON or OFF	ON: Brake pedal depressed OFF: Brake pedal released	-

   OK

   Display changes according to brake pedal operation described in the table above.

6. Turn the power switch off.

NG → See step   10 

OK: Go to next step 

1. Disconnect the A28 stop light switch assembly connector.
2. Disconnect the A24 skid control ECU (brake booster with master cylinder assembly) connector.
3. Measure the resistance according to the value(s) in the table below.

   Standard Resistance (Check for Open)

   Tester Connection	Condition	Specified Condition
   A28-2 (L) - A24-33 (STP)	Always	Below 1 Ω

   Standard Resistance (Check for Short)

   Tester Connection	Condition	Specified Condition
   A28-2 (L) or A24-33 (STP) - Body ground	Always	10 kΩ or higher

4. Reconnect the A24 skid control ECU (brake booster with master cylinder assembly) connector.
5. Reconnect the A28 stop light switch assembly connector.

NG → REPAIR OR REPLACE HARNESS OR CONNECTOR 

OK: Go to next step 

1. Remove the engine room junction block assembly from the engine room relay block and junction block assembly.
2. Disconnect the A24 skid control ECU (brake booster with master cylinder assembly) connector.
3. Measure the resistance according to the value(s) in the table below.

   Standard Resistance (Check for Open)

   Tester Connection	Condition	Specified Condition
   1G-3 (ACC) - A24-3 (STPO)	Always	Below 1 Ω
   1F-7 (ESS) - A24-21 (EXO)	Always	Below 1 Ω
   1F-16 (STPS) - A24-33 (STP)	Always	Below 1 Ω
   1F-11 (STOP) - A24-6 (STP2)	Always	Below 1 Ω

   Standard Resistance (Check for Short)

   Tester Connection	Condition	Specified Condition
   1G-3 (ACC) or A24-3 (STPO) - Body ground	Always	10 kΩ or higher
   1F-7 (ESS) or A24-21 (EXO) - Body ground	Always	10 kΩ or higher
   1F-16 (STPS) or A24-33 (STP) - Body ground	Always	10 kΩ or higher
   1F-11 (STOP) or A24-6 (STP2) - Body ground	Always	10 kΩ or higher

4. Reconnect the A24 skid control ECU (brake booster with master cylinder assembly) connector.
5. Install the engine room junction block assembly to the engine room relay block and junction block assembly.

NG → REPAIR OR REPLACE HARNESS OR CONNECTOR 

OK: Go to next step 

Refer to ON-VEHICLE INSPECTION [08/2013 - ]

NG → See step   15 

OK: Go to next step 

Refer to REMOVAL [08/2013 - ]

NEXT: Go to next step 

1. Connect the Techstream to the DLC3.
2. Turn the power switch on (IG).
3. Clear the DTCs. Refer to DTC CHECK / CLEAR [08/2013 - ] .
4. Perform the following to make sure that the DTC detection conditions are met.

   HINT: 

   If the detection conditions are not met, the malfunction cannot be detected.

   1. Drive the vehicle at a speed for which cruise control operation is possible.
   2. Turn the cruise control system on using the cruise control switch (ON-OFF button).
   3. Push the cruise control switch to -/SET to begin control of vehicle speed by the dynamic radar cruise control system.
5. Enter the following menus: Powertrain / Radar Cruise / Trouble Codes.
6. Check for DTCs.

   Result

   Result	Proceed to
   DTC is not output	A
   DTC C1A05 is output	B

7. Turn the power switch off.

B → See step   8 

A → END 

Refer to REMOVAL [08/2013 - ]

NEXT: Go to next step 

1. Connect the Techstream to the DLC3.
2. Turn the power switch on (IG).
3. Clear the DTCs. Refer to DTC CHECK / CLEAR [08/2013 - ] .
4. Perform the following to make sure that the DTC detection conditions are met.

   HINT: 

   If the detection conditions are not met, the malfunction cannot be detected.

   1. Drive the vehicle at a speed for which cruise control operation is possible.
   2. Turn the cruise control system on using the cruise control switch (ON-OFF button).
   3. Push the cruise control switch to -/SET to begin control of vehicle speed using the cruise control system.
5. Enter the following menus: Powertrain / Radar Cruise / Trouble Codes.
6. Check for DTCs.

   Result

   Result	Proceed to
   DTC is not output	A
   DTC C1A05 is output	B

7. Turn the power switch off.

B → See step   16 

A → END 

1. Disconnect the A28 stop light switch assembly connector.
2. Measure the voltage according to the value(s) in the table below.

   Courtesy of © TOYOTA, LICENSE AGREEMENT TMS1002

   Standard Voltage

   Tester Connection	Condition	Specified Condition
   A28-1 (B) - A28-3 (GND)	Power switch off	11 to 14 V
   A28-5 (B) - A28-3 (GND)	Power switch ON	11 to 14 V

   TEXT IN ILLUSTRATION
   
   

   *a	Front view of wire harness connector (to Stop Light Switch Assembly)

3. Measure the resistance according to the value(s) in the table below.

   Standard Resistance

   Tester Connection	Condition	Specified Condition
   A28-3 (GND) - Body ground	Always	Below 1 Ω

4. Reconnect the A28 stop light switch assembly connector.

NG → REPAIR OR REPLACE HARNESS OR CONNECTOR 

OK: Go to next step 

1. Measure the voltage according to the value(s) in the table below.

   Courtesy of © TOYOTA, LICENSE AGREEMENT TMS1002

   Standard Voltage

   Tester Connection	Condition	Specified Condition
   A28-2 (L) - A28-3 (GND)	Power switch off, brake pedal not depressed	Below 1 V
   	Power switch off, brake pedal depressed	11 to 14 V
   A28-4 (L) - A28-3 (GND)	Power switch ON, brake pedal not depressed	11 to 14 V
   	Power switch ON, brake pedal depressed	Below 1 V

   TEXT IN ILLUSTRATION
   
   

   *a	Component with harness connected (Stop Light Switch Assembly)

NG → See step   14 

OK: Go to next step 

1. Disconnect the A28 stop light switch assembly connector.
2. Disconnect the H75 driving support ECU assembly connector.
3. Measure the resistance according to the value(s) in the table below.

   Standard Resistance (Check for Open)

   Tester Connection	Condition	Specified Condition
   A28-4 (L) - H75-28 (ST1-)	Always	Below 1 Ω
   A28-2 (L) - H75-27 (STP-)	Always	Below 1 Ω

   Standard Resistance (Check for Short)

   Tester Connection	Condition	Specified Condition
   A28-4 (L) or H75-28 (ST1-) - Body ground	Always	10 kΩ or higher
   A28-2 (L) or H75-27 (STP-) - Body ground	Always	10 kΩ or higher

4. Reconnect the H75 driving support ECU assembly connector.
5. Reconnect the A28 stop light switch assembly connector.

NG → REPAIR OR REPLACE HARNESS OR CONNECTOR 

OK: Go to next step 

1. Disconnect the A33 power management control ECU connector.
2. Disconnect the H75 driving support ECU assembly connector.
3. Measure the resistance according to the value(s) in the table below.

   Standard Resistance (Check for Open)

   Tester Connection	Condition	Specified Condition
   A33-7 (ST1-) - H75-28 (ST1-)	Always	Below 1 Ω
   A33-23 (STP) - H75-27 (STP-)	Always	Below 1 Ω

   Standard Resistance (Check for Short)

   Tester Connection	Condition	Specified Condition
   A33-7 (ST1-) or H75-28 (ST1-) - Body ground	Always	10 kΩ or higher
   A33-23 (STP) or H75-27 (STP-) - Body ground	Always	10 kΩ or higher

4. Reconnect the H75 driving support ECU assembly connector.
5. Reconnect the A33 power management control ECU connector.

NG → REPAIR OR REPLACE HARNESS OR CONNECTOR 

OK → See step   17