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For 1990-2009 cars only

DTC P0719 Brake Switch Circuit Low Input 3.1L


Object Number: 106825  Size: SF

Circuit Description

The Torque Converter Clutch (TCC) brake switch reports brake pedal status to the Powertrain Control Module (PCM). The brake switch indicates that the brake pedal is either applied or released. The normally-closed switch supplies battery voltage on circuit 420 to the PCM. Applying the brake pedal opens the brake switch, interrupting voltage to the PCM. When the PCM receives 0 volts at the brake switch input, the PCM turns OFF the TCC Solenoid Valve.

When the PCM detects an open brake switch (stuck ON) during acceleration, then DTC P0719 sets. DTC P0719 is a type D DTC.

Conditions for Setting the DTC

    • No VSS DTCs P0502 or P0503.
    • The vehicle speed is less than 8 km/h (5 mph).
    • Accelerate the vehicle to 32 km/h (20 mph) taking 4 seconds.
    • The vehicle speed remains above 32 km/h (20 mph) for 6 seconds.
    • The above conditions must occur 7 times with the brake switch ON for more than 15 minutes, and the PCM receiving no voltage input for 2 seconds.

Action Taken When the DTC Sets

    • Disregard the brake switch for TCC scheduling when all of the following conditions are met:
       - The throttle position is greater than 6%.
       - The vehicle speed is greater than 70 km/h (44 mph).
       - The throttle position was previously greater than 12%, while the vehicle speed was greater than 72 km/h (47 mph).
       - The brake switch has not been OFF for more than 2 seconds during this ignition cycle.
    • The PCM does not illuminate the Malfunction Indicator Lamp (MIL).

Conditions for Clearing the DTC

    • A scan tool can clear the DTC from the PCM history. The PCM clears the DTC from the PCM history if the vehicle completes 40 warm-up cycles without a failure reported.
    • The PCM cancels the DTC default actions when the fault no longer exists and the ignition is OFF long enough in order to power down the PCM.

Diagnostic Aids

    • Ensure that the TCC brake switch is properly adjusted.
    • Check the PCM calibration for a current update.
    • Inspect the wiring for poor electrical connections at the PCM. Inspect the wiring at the Automatic Transmission 7-way connector. Look for the following conditions:
       - A bent terminal
       - A backed out terminal
       - A damaged terminal
       - Poor terminal tension
       - A chafed wire
       - A broken wire inside the insulation
    • When diagnosing for an intermittent short or open condition, massage the wiring harness while watching the test equipment for a change.

Test Description

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

  1. This step isolates the fault between the TCC Brake Switch and the harness.

DTC P0719 TCC Brake Switch Circuit Low (3.1L) Buick

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

2

  1. Install the Scan Tool ®.
  2. With the engine OFF, turn the ignition switch to the RUN position.
  3. Important: Before clearing the DTCs, use the scan tool in order to record the Failure Records for reference. The Clear Info function will erase the data.

  4. Record the DTC Failure Records.
  5. Select TCC Brake Switch on the scan tool.
  6. Apply the brake pedal.

Does the status change from Open to Closed?

--

Go to Diagnostic Aids

Go to Step 3

3

Inspect the ENG EMIS fuse for an open.

Was the condition found and corrected?

--

Go to Step 4

Go to Step 5

4

  1. Inspect circuits 339 and 420 for a short to ground.
  2. Repair circuits 339 and 420 if necessary. Refer to Troubleshooting Procedures, Section 8.

Was a condition found and corrected?

--

Go to Step 10

Go to Diagnostic Aids

5

  1. Select Brake Switch on the scan tool.
  2. Disconnect the TCC brake switch.
  3. Install a fused jumper from terminal C to terminal D of the brake switch connector using a J 35616-A Connector Test Adapter Kit.

Does the brake status change from Open to Closed?

--

Go to Step 6

Go to Step 7

6

Replace the TCC brake switch. Refer to Brake Switch Replacement, Section 5.

Is the replacement complete?

--

Go to Step 10

--

7

  1. Inspect circuits 420 and 1339 for an open.
  2. Repair circuits 420 and 1339 if necessary. Refer to Troubleshooting Procedures, Section 8.

Was a condition found and corrected?

--

Go to Step 10

Go to Step 8

8

Inspect PCM connector C1 for bent, damaged or backed out connector pins.

Was a condition found and corrected?

--

Go to Step 10

Go to Step 9

9

Replace the PCM. Refer to Powertrain Control Module Replacement/Programming , Section 6.

Is the replacement complete?

--

Go to Step 10

--

10

In order to verify your repair, perform the following procedure:

  1. Select DTC.
  2. Select Clear Info.
  3. Operate the vehicle under the following conditions:
  4. • Turn the ignition switch to the RUN position.
    • The TCC brake switch must be OFF for more than 2 seconds.
  5. Select Specific DTC. Enter DTC P0719.

Has the test run and passed?

--

System OK

Begin the diagnosis again. Go to Step 1

DTC P0719 Brake Switch Circuit Low Input 3.8L


Object Number: 106825  Size: SF

Circuit Description

The Torque Converter Clutch (TCC) brake switch reports brake pedal status to the Powertrain Control Module (PCM). The brake switch indicates that the brake pedal is either applied or released. The normally-closed switch supplies battery voltage on circuit 420 to the PCM. Applying the brake pedal opens the brake switch, interrupting voltage to the PCM. When the PCM receives 0 volts at the brake switch input, the PCM turns OFF the TCC Solenoid Valve.

When the PCM detects an open brake switch (stuck ON) during acceleration, then DTC P0719 sets. DTC P0719 is a type D DTC.

Conditions for Setting the DTC

    • No VSS DTCs P0502 or P0503.
    • The vehicle speed is less than 8 km/h (5 mph).
    • Accelerate the vehicle to 32 km/h (20 mph) taking 4 seconds.
    • The vehicle speed remains above 32 km/h (20 mph) for 6 seconds.
    • The above conditions must occur 7 times with the brake switch ON for more than 15 minutes, and the PCM receiving no voltage input for 2 seconds.

Action Taken When the DTC Sets

    • Disregard the brake switch for TCC scheduling when all of the following conditions are met:
       - The throttle position is greater than 6%.
       - The vehicle speed is greater than 70 km/h (44 mph).
       - The throttle position was previously greater than 12%, while the vehicle speed was greater than 72 km/h (47 mph).
       - The brake switch has not been OFF for more than 2 seconds during this ignition cycle.
    • The PCM does not illuminate the Malfunction Indicator Lamp (MIL).

Conditions for Clearing the DTC

    • A scan tool can clear the DTC from the PCM history. The PCM clears the DTC from the PCM history if the vehicle completes 40 warm-up cycles without a failure reported.
    • The PCM cancels the DTC default actions when the fault no longer exists and the ignition is OFF long enough in order to power down the PCM.

Diagnostic Aids

    • Ensure that the TCC brake switch is properly adjusted.
    • Check the PCM calibration for a current update.
    • Inspect the wiring for poor electrical connections at the PCM. Inspect the wiring at the TCC Brake Switch. Look for the following conditions:
       - A bent terminal
       - A backed out terminal
       - A damaged terminal
       - Poor terminal tension
       - A chafed wire
       - A broken wire inside the insulation
    • When diagnosing for an intermittent short or open condition, massage the wiring harness while watching the test equipment for a change.

Test Description

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

  1. This step isolates the fault between the TCC Brake Switch and the harness.

DTC P0719 TCC Brake Switch Circuit Low (3.8L) Buick

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

2

  1. Install the Scan Tool ®.
  2. With the engine OFF, turn the ignition switch to the RUN position.
  3. Important: Before clearing the DTCs, use the scan tool in order to record the Failure Records for reference. The Clear Info function will erase the data.

  4. Record the DTC Failure Records.

Are DTCs P0753, P0758 and P0740 also set?

--

Go to Step 3

Go to Step 5

3

Inspect the TCC fuse for an open.

Was the condition found and corrected?

--

Go to Step 4

--

4

  1. Inspect circuits 339 and 420 for a short to ground.
  2. Repair circuits 339 and 420 if necessary. Refer to Troubleshooting Procedures, Section 8.

Was the condition found and corrected?

--

Go to Step 10

Go to Diagnostic Aids

5

  1. Select Brake Switch on the scan tool.
  2. Disconnect the TCC brake switch.
  3. Install a fused jumper from terminal C to terminal D of the brake switch connector.

Does the brake status change from Open to Closed?

--

Go to Step 6

Go to Step 7

6

Replace the TCC brake switch. Refer to Brake Switch Replacement, Section 5.

Is the replacement complete?

--

Go to Step 10

--

7

  1. Inspect circuits 420 and 1039 for an open.
  2. Repair circuits 420 and 1039 if necessary. Refer to Troubleshooting Procedures, Section 8.

Was the condition found and corrected?

--

Go to Step 10

Go to Step 8

8

Inspect PCM connector C1 for bent, damaged or backed out connector pins.

Was the condition found and corrected?

--

Go to Step 10

Go to Step 9

9

Replace the PCM. Refer to Powertrain Control Module Replacement/Programming , Section 6.

Is the replacement complete?

--

Go to Step 10

--

10

In order to verify your repair, perform the following procedure:

  1. Select DTC.
  2. Select Clear Info.
  3. Operate the vehicle under the following conditions:
  4. • Turn the ignition switch to the RUN position.
    • The TCC brake switch must be OFF for more than 2 seconds.
  5. Select Specific DTC. Enter DTC P0719.

Has the test run and passed?

--

System OK

Begin the diagnosis again. Go to Step 1