Step | Action | Value(s) | Yes | No |
|---|---|---|---|---|
1 |
Does the park brake pump motor continue to run? | -- | Go to Step 2 | |
2 | Observe the park brake pressure solenoid valve while disconnecting the park brake pressure solenoid valve. Does the park brake pressure solenoid valve click when it is disconnected? | -- | Go to Step 3 | Go to Step 5 |
3 |
Does the test lamp light? | -- | Go to Step 4 | Go to Step 8 |
4 | Locate and repair the short to voltage in CKT 1931 (YEL/BLK), or CKT 504 (YEL/BLK), or CKT 517 (YEL/BLK) between the park brake relay, the park brake control module, and the park brake pressure solenoid valve. Is the repair complete? | -- | System OK | -- |
5 |
Is the resistance between the specified limits? | 65 ohms-80 ohms | Go to Step 6 | Go to Step 7 |
6 | Refer to CAUTION:: This system operates using fluid pressure up to 12 400 kPa (1800 psi). Some malfunctions can cause this pressure to be trapped in the system. Use caution when loosening pipe fittings on a system that does not work or personal injury can result. in Cautions and Notices.
Is any fluid leaving the fitting? | -- | Go to Step 8 | |
7 | Replace the park brake pressure solenoid valve. Refer to Park Brake Solenoid Valve Replacement . Is the repair complete? | -- | System OK | -- |
8 | Connect a test lamp from the park brake relay connector terminal 86 to ground. Does the test lamp light? | -- | Go to Step 9 | Go to Step 10 |
9 | Check for a short to voltage in CKT 3 (YEL/BLK), or CKT 523 (YEL/BLK) between the park brake switch and the park brake relay. Is the repair complete? | -- | System OK | Go to Step 11 |
10 | Replace the park brake relay. Refer to Parking Brake Relay Switch Replacement . Is the repair complete? | -- | System OK | -- |
11 | Replace the park brake switch. Is the repair complete? | -- | System OK | -- |
