Circuit Description
The brake switch indicates brake pedal status to the powertrain control module (PCM). When the brake pedal is operated, the switch sends a signal to the PCM, the PCM then cancels the operation of the TCC lock-up while braking is in progress. This prevents the engine from stalling.
Conditions for Running the DTC
| • | The switch does not turn off even once the vehicle is driven (2-trip detection logic). |
| • | The ignition is ON. |
Conditions for Setting the DTC
The PCM detects a closed brake switch circuit, 12 volts, without changing for 2 seconds and the following events occur eight times:
The vehicle must stop and go from 3 km/h (2 mph) to 30 km/h (19 mph) ten times for two driving cycles before detecting a malfunction.
Action Taken When the DTC Sets
| • | The PCM illuminates the malfunction indicator lamp (MIL). |
| • | The PCM stores DTC P0724 in PCM history. |
Conditions for Clearing the DTC
| • | A scan tool can clear the DTC. |
| • | The PCM clears the DTC from PCM history if the vehicle completes 40 warm-up cycles without a non-emission-related diagnostic fault occurring. |
| • | The PCM cancels the DTC default actions when the fault no longer exists and/or the ignition switch is OFF long enough in order to power down the PCM. |
Diagnostic Aids
Inspect the brake switch for proper mounting and operation.
Test Description
The numbers below refer to the step numbers on the diagnostic table.
Step | Action | Value(s) | Yes | No |
|---|---|---|---|---|
Schematic Reference: Automatic Transmission Controls Schematics | ||||
1 | Did you perform the Powertrain Diagnostic System Check? | -- | Go to Step 2 | Go to Diagnostic System Check - Engine Controls in Engine Controls - 1.8L (LV6) |
Important: Before clearing the DTC, use the scan tool in order to record the Failure Records. Using the Clear Info function erases the Failure Records from the PCM. Caution: Refer to SIR Caution in the Preface section. Did the Brake Switch status change from Closed to Open? | -- | Go to Step 3 | Go to Step 4 | |
3 | Replace the brake switch. Refer to Stop Lamp Switch Replacement in Hydraulic Brakes. Did you complete the replacement? | -- | Go to Step 6 | -- |
4 | Test the signal circuit of the brake switch for a short to power. Did you find and correct the condition? | -- | Go to Step 6 | Go to Step 5 |
5 | Replace the PCM. Refer to Powertrain Control Module Replacement in Engine Controls - 1.8L (LV6). Did you complete the replacement? | -- | Go to Step 6 | -- |
6 | Perform the following procedure in order to verify the repair:
Has the test run and passed? | 0 volts | System OK | Go to Step 1 |
