DESCRIPTION
The skid control ECU (brake actuator assembly) detects the brake operating conditions through a signal transmitted by the stop light switch.
The skid control ECU incorporates a circuit to detect an open circuit. This DTC is output when an open circuit is detected in the stop light signal input line.
| DTC No. | Detection Item | DTC Detection Condition | Trouble Area | Note |
|---|---|---|---|---|
| C1425 | Open in Stop Light Switch Circuit | When voltage at terminal +BS is 9.5 to 17.4 V, open circuit occurs between STP terminal circuits A and B for 0.3 seconds or more (except restart due to stop and start control*). |
|
- |
*: w/ Stop and Start System
WIRING DIAGRAM
CAUTION / NOTICE / HINT
Note
When replacing the skid control ECU (brake actuator assembly), perform zero point calibration and store system information.
PROCEDURE
READ VALUE USING GTS (STOP LIGHT SWITCH ASSEMBLY)
Connect the GTS to the DLC3.
Turn the engine switch on (IG).
Select the Data List on the GTS.
| Tester Display | Measurement Item | Range | Normal Condition | Diagnostic Note |
|---|---|---|---|---|
| Stop Light SW | Stop light switch assembly | ON or OFF | OFF: Brake pedal released ON: Brake pedal depressed |
- |
| Tester Display |
|---|
| Stop Light SW |
Check that the stop light switch assembly condition observed on the GTS changes according to brake pedal operation.
| OK |
|---|
| The GTS displays ON or OFF according to brake pedal operation. |
| Result | |||
|---|---|---|---|
|
| NG |
|
CHECK TERMINAL VOLTAGE (STP TERMINAL) Click here |
| OK |
|
RECONFIRM DTC
Turn the engine switch off.
Clear the DTCs.
Turn the engine switch off.
Start the engine.
Depress the brake pedal several times to test the stop light circuit.
Check if the same DTC is recorded.
Tech Tips
If troubleshooting has been carried out according to the Problem Symptoms Table, refer back to the table and proceed to the next step.
| Result | |||
|---|---|---|---|
|
| DTC C1425 is not output |
|
USE SIMULATION METHOD TO CHECK Click here |
| DTC C1425 is output |
|
REPLACE BRAKE ACTUATOR ASSEMBLY Click here |
CHECK TERMINAL VOLTAGE (STP TERMINAL)
| *a | Front view of wire harness connector (to Skid Control ECU [Brake Actuator Assembly]) |
Turn the engine switch off.
Make sure that there is no looseness at the locking part and the connecting part of the connectors.
Disconnect the A36 skid control ECU (brake actuator assembly) connector.
Measure the voltage according to the value(s) in the table below.
| Standard Voltage | ||||||||
|---|---|---|---|---|---|---|---|---|
|
| Result | |||
|---|---|---|---|
|
| OK |
|
REPLACE BRAKE ACTUATOR ASSEMBLY Click here |
| NG |
|
REPAIR OR REPLACE HARNESS OR CONNECTOR (BRAKE ACTUATOR ASSEMBLY - STOP LIGHT CIRCUIT) |