- Micro switch signal PSNC and PSNO logic malfunction.
- When brake pedal is not depressed, micro switch turns on.
- When brake pedal is depressed, micro switch turns off.
| Last Modified: 11-29-2007 | 1.6 C | |
| Service Category: Brake | Section: Brake Control/Dynamic Control System | |
| Model Year: 2008 | Model: Sequoia | Doc ID: RM000001P4S005X |
| Title: BRAKE CONTROL / DYNAMIC CONTROL SYSTEMS: VEHICLE STABILITY CONTROL SYSTEM: DESCRIPTION (2008 Sequoia) | ||
|
DTC |
C1267/28 |
Brake Pedal Load Sensing Switch |
DESCRIPTION
The skid control ECU detects if the brake pedal is depressed.
|
DTC Code |
DTC Detection Condition |
Trouble Area |
|---|---|---|
|
C1267/28 |
When one of following conditions is met: |
|
WIRING DIAGRAM
INSPECTION PROCEDURE
NOTICE:
When replacing the VSC actuator assembly, perform zero point calibration
.
PROCEDURE
|
1. |
CHECK TERMINAL VOLTAGE (BOOSTER PEDAL MICRO SWITCH) |
|
(a) Disconnect A20 booster connector. |
(b) Turn the ignition switch to ON.
(c) Measure the voltage according to the value(s) in the table below.
Standard Voltage:
|
Tester Connection |
Switch Condition |
Specified Condition |
|---|---|---|
|
A20-5 (STS) - Body ground |
Ignition switch ON |
Approximately 12 V |
|
|
2. |
INSPECT BOOSTER PEDAL MICRO SWITCH |
(a) When using an oscilloscope:
(1) Connect the oscilloscope between terminals 1 (PSNO) and 5 (STS), 2 (PSNC) and 5 (STS) of the brake booster with connector being connected.
(2) Turn the ignition switch to ON.
(3) Check the signal waveform while the brake pedal is depressed and released.
OK:
Signal waveform changes as shown in the illustration.
|
(b) When not using an oscilloscope: (1) Disconnect the A20 booster connector. (2) Turn the ignition switch to ON. (3) Measure the voltage according to the value(s) in the table below. Standard Voltage:
|
|
|
3. |
CHECK HARNESS AND CONNECTOR (BOOSTER PEDAL MICRO SWITCH - SKID CONTROL ECU) |
|
(a) Confirm that the skid control ECU connector and brake booster connector are properly connected. |
(b) Disconnect the A19 ECU connector.
(c) Disconnect the A20 booster connector.
(d) Inspect both the connector case and the terminal for deformation and corrosion.
OK:
No deformation or corrosion.
(e) Measure the resistance according to the value(s) in the table below.
Standard Resistance:
|
Tester Connection |
Condition |
Specified Condition |
|---|---|---|
|
A19-24 (PSNO) - A20-1 (PSNO) |
Always |
Below 1 Ω |
|
A19-24 (PSNO) - Body ground |
Always |
10 kΩ or higher |
|
A19-25 (PSNC) - A20-2 (PSNC) |
Always |
Below 1 Ω |
|
A19-25 (PSNC) - Body ground |
Always |
10 kΩ or higher |
|
A19-27 (STS) - A20-5 (STS) |
Always |
Below 1 Ω |
|
A19-27 (STS) - Body ground |
Always |
10 kΩ or higher |
|
|
|