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Makes 🢒 Pontiac 🢒 1999 🢒 Firebird 🢒 DTC 🢒 DTC P0724 Brake Switch Circuit High Input

DTC P0724 Brake Switch Circuit High Input 5.7L


Object Number: 331462 Size: MF
Automatic Transmission Components V8 VIN G
Automatic Transmission Controls Schematics
OBD II Symbol Description Notice
Handling ESD Sensitive Parts Notice

Circuit Description

The brake switch indicates brake pedal status to the powertrain control module (PCM). The brake switch is a normally-closed switch that supplies battery voltage on circuit 420 to the PCM. Applying the brake pedal opens the switch, interrupting voltage to the PCM. When the brake pedal is released, the PCM receives a constant voltage signal. If the PCM receives a zero voltage signal at the brake switch input, and the torque converter clutch (TCC) is engaged, the PCM de-energizes the TCC solenoid valve. The PCM disregards the brake switch input for TCC scheduling if there is a brake switch circuit fault.

When the PCM detects a closed brake switch circuit (12 volts, high input) during decelerations, then DTC P0724 sets. DTC P0724 is a type D DTC.

Conditions for Running the DTC
    • No VSS assembly DTCs P0502 or P0503.
    • The ignition switch is in the RUN position.

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 seven times:

    • The vehicle speed is greater than 32 km/h (20 mph) for 6 seconds;
    • then the vehicle speed is 8-32 km/h (5-20 mph) for 4 seconds;
    • then the vehicle speed is less than 8 km/h (5 mph).

Action Taken When the DTC Sets
    • The PCM does not illuminate the malfunction indicator lamp (MIL).
    • The PCM stores DTC P0724 in PCM history.

Conditions for Clearing the DTC
    • A scan tool clears the DTC from PCM history.
    • The PCM clears the DTC from PCM history if the vehicle completes 40 consecutive 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 the ignition switch is OFF long enough in order to power down the PCM.

Diagnostic Aids
    • Inspect the wiring at the PCM, the brake switch connector and all other circuit connecting points for the following conditions:
       - A backed out terminal
       - A damaged terminal
       - Reduced terminal tension
       - A chafed wire
       - A broken wire inside the insulation
       - Moisture intrusion
       - Corrosion
    • When diagnosing for an intermittent short or open condition, massage the wiring harness while watching the test equipment for a change.
    • Ask about the customer's driving habits. Ask about unusual driving conditions (e.g. stop and go, expressway, etc.).
    • Inspect the brake switch for proper mounting and operation.

Test Description

The numbers below refer to the step numbers on the diagnostic table.

  1. This step isolates the brake switch as a source for setting the DTC.

DTC P0724 Brake Switch Circuit High (5.7L, VIN G)

Step

Action

Value(s)

Yes

No

1

Was the Powertrain On-Board Diagnostic (OBD) System Check performed?

--

Go to Step 2

Go to Powertrain On Board Diagnostic (OBD) System Check in Engine Controls

2
  1. Install the Scan Tool .
  2. With the engine OFF, turn the ignition switch to the RUN position.

    3. 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.

  3. Record the DTC Failure Records.
  4. Clear the DTC.
  5. Select TCC Brake Switch on the scan tool.
  6. Disconnect the brake switch connector from the brake switch.

Did the TCC 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 .

Is the replacement complete?

--

Go to Step 6

--

4
  1. Inspect circuit 420 (PPL) for a short to B+ condition.

    2. Refer to General Electrical Diagnosis in Wiring Systems.

  2. Repair the circuit if necessary.

    3. Refer to Wiring Repairs in Wiring Systems.

Did you find a short to B+ condition?

--

Go to Step 6

Go to Step 5

5

Replace the PCM.

Refer to Powertrain Control Module Replacement/Programming in Engine Controls.

Is the replacement complete?

--

Go to Step 6

--

6

Perform the following procedure in order to verify the repair:

  1. Select DTC.
  2. Select Clear Info.
  3. With the engine OFF, turn the ignition switch to the RUN position.
  4. Apply and release the brake pedal.
  5. Verify that the scan tool TCC Brake Switch status indicates Open (0 volts) for 2 seconds.
  6. Select Specific DTC.
  7. Enter DTC P0724.

Has the test run and passed?

--

System OK

Go to Step 1

DTC P0724 Brake Switch Circuit High Input 3.8L


Object Number: 341147 Size: MF
Automatic Transmission Components V6 VIN K
Automatic Transmission Controls Schematics
OBD II Symbol Description Notice
Handling ESD Sensitive Parts Notice

Circuit Description

The brake switch indicates brake pedal status to the powertrain control module (PCM). The brake switch is a normally-closed switch that supplies battery voltage on circuit 420 to the PCM. Applying the brake pedal opens the switch, interrupting voltage to the PCM. When the brake pedal is released, the PCM receives a constant voltage signal. If the PCM receives a zero voltage signal at the brake switch input, and the torque converter clutch (TCC) is engaged, the PCM de-energizes the TCC solenoid valve. The PCM disregards the brake switch input for TCC scheduling if there is a brake switch circuit fault.

When the PCM detects a closed brake switch circuit (12 volts, high input) during decelerations, then DTC P0724 sets. DTC P0724 is a type D DTC.

Conditions for Running the DTC
    • No VSS assembly DTCs P0502 or P0503.
    • The ignition switch is in the RUN position.

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 seven times:

    • The vehicle speed is greater than 32 km/h (20 mph) for 6 seconds;
    • then the vehicle speed is 8-32 km/h (5-20 mph) for 4 seconds;
    • then the vehicle speed is less than 8 km/h (5 mph).

Action Taken When the DTC Sets
    • The PCM does not illuminate the malfunction indicator lamp (MIL).
    • The PCM stores DTC P0724 in PCM history.

Conditions for Clearing the DTC
    • A scan tool clears the DTC from PCM history.
    • The PCM clears the DTC from PCM history if the vehicle completes 40 consecutive 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 the ignition switch is OFF long enough in order to power down the PCM.

Diagnostic Aids
    • Inspect the wiring at the PCM, the brake switch connector and all other circuit connecting points for the following conditions:
       - A backed out terminal
       - A damaged terminal
       - Reduced terminal tension
       - A chafed wire
       - A broken wire inside the insulation
       - Moisture intrusion
       - Corrosion
    • When diagnosing for an intermittent short or open condition, massage the wiring harness while watching the test equipment for a change.
    • Ask about the customer's driving habits. Ask about unusual driving conditions (e.g. stop and go, expressway, etc.).
    • Inspect the brake switch for proper mounting and operation.

Test Description

The numbers below refer to the step numbers on the diagnostic table.

  1. This step isolates the brake switch as a source for setting the DTC.

DTC P0724 Brake Switch Circuit High (3.8L, VIN K)

Step

Action

Value(s)

Yes

No

1

Was the Powertrain On-Board Diagnostic (OBD) System Check performed?

--

Go to Step 2

Go to Powertrain On Board Diagnostic (OBD) System Check in Engine Controls

2
  1. Install the Scan Tool .
  2. With the engine OFF, turn the ignition switch to the RUN position.

    3. 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.

  3. Record the DTC Failure Records.
  4. Clear the DTC.
  5. Select TCC Brake Switch on the scan tool.
  6. Disconnect the brake switch connector from the brake switch.

Did the TCC 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.

Is the replacement complete?

--

Go to Step 6

--

4
  1. Inspect circuit 420 (PPL) for a short to B+ condition.

    2. Refer to General Electrical Diagnosis in Wiring Systems.

  2. Repair the circuit if necessary.

    3. Refer to Wiring Repairs in Wiring Systems.

Did you find a short to B+ condition?

--

Go to Step 6

Go to Step 5

5

Replace the PCM.

Refer to Powertrain Control Module Replacement/Programming in Engine Controls.

Is the replacement complete?

--

Go to Step 6

--

6

Perform the following procedure in order to verify the repair:

  1. Select DTC.
  2. Select Clear Info.
  3. With the engine OFF, turn the ignition switch to the RUN position.
  4. Apply and release the brake pedal.
  5. Verify that the scan tool TCC Brake Switch status indicates Open (0 volts) for 2 seconds.
  6. Select Specific DTC.
  7. Enter DTC P0724.

Has the test run and passed?

--

System OK

Go to Step 1