DTC P0719 Brake Switch Circuit Low Input. Cadillac Concours 1997

For 1990-2009 cars
Automatic Transmission Components
Brake Switch, Solenoids, and VSS
Handling ESD Sensitive Parts Notice
OBD II Symbol Description Notice

### Circuit Description

The Torque Converter Clutch (TCC) brake switch is used to indicate the status of the brake pedal (applied or released).

When the Powertrain Control Module (PCM) detects a status change on the brake lamp switch and the extended travel brake switch input without a transition on the TCC brake switch input, then DTC P0719 sets. DTC P0719 is a Type C DTC.

### Conditions for Setting the DTC

• | No VSS DTCs P0502 or P0503.

• | No extended travel or stop lamp DTCs P1574 or P1575.

• | No loss of PCM serial data P1602.

• | Traction control or ABS module has not failed.

• | The difference in vehicle speed and a non-driven wheel speed is less than 10 km/h (6 mph).

• | The TCC brake switch input is at 0 volts.

• | DTC P0719 has not passed this ignition cycle.

• | The following conditions must occur 7 times within 15 minutes without a status change on the TCC brake input.

1. | The vehicle speed is less than 8 km/h (5 mph).

2. | The vehicle accelerates to 32 km/h (20 mph) taking longer than 2.5 seconds.

3. | Then the vehicle speed remains above 32 km/h (20 mph) for 6 seconds.

### Action Taken When the DTC Sets

• | The PCM does not illuminate the Malfunction Indicator Lamp (MIL).

• | SERVICE ELECTRICAL SYSTEM displays on the Driver Information Center (DIC).

• | The PCM uses the extended travel brake switch input or the stop lamp switch input for TCC control.

• | The PCM disables garage shift adapts.

• | DTC P0719 is stored in the PCM history.

### Conditions for Clearing the DIC/DTC

• | The brake switch input must indicate voltage OFF for 2 seconds.

• | 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

• | Inspect the TCC brake switch for proper adjustment.

• | Check the customer's driving habits.

• | Inspect the wiring for poor electrical connections at the PCM. Inspect the wiring for poor electrical connections at the brake switch connector. Look for the following problems:

- | A bent terminal

- | A backed out terminal

- | A damaged terminal

- | Poor terminal tension

- | A chafed wire

- | A broken wire inside the insulation

- | Moisture intrusion

• | When diagnosing for an intermittent short or open, 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. If the fuse is open, inspect circuit 1039, circuit 420, or circuit 847 for a short to ground. Circuit 847 is the input to the PCM from the extended travel brake switch.

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

3. If the brake switch was adjusted properly, then replace the brake switch.

#### DTC P0719 Brake Switch Circuit Low Input

Step | Action | Value(s) | Yes | No
--- | --- | --- | --- | ---
1 | Was the Powertrain On-Board Diagnostic (OBD) System Check performed? | -- | Go to Step 2 | Go to A 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.

Important: Before clearing the DTCs, use the scan tool in order to record the Failure Records for reference. Using the Clear Info function will erase the stored Failure Records from the PCM.

3. Record the DTC Failure Records, then clear the DTC.

Are DTCs 1574 or 1575 also set?

--

Go to Step 3

Go to Step 5

3

1. Remove the RLY IGN 12 fuse.
2. Inspect the fuse for an open.

Refer to Electrical Diagnosis, Section 8.

Is the fuse open?

--

Go to Step 4

--

4

Inspect the following circuits for a short to ground:

• | Circuit 1039

• | Circuit 420

• | Circuit 847

Refer to Electrical Diagnosis, Section 8.

Did you find and correct the condition?

--

Go to Step 9

--

5

1. Select TCC Brake Switch on the scan tool.
2. Disconnect the TCC Brake Switch.
3. Using the J 35616-A Connector Test Adapter Kit, install a fused jumper from terminal A to terminal B of the brake switch connector.

Does the brake status change from Applied to Released?

--

Go to Step 6

Go to Step 7

6 | Replace the Brake Switch. Refer to Brake Switch Replacement, Section 5. Is the replacement complete? | -- | Go to Step 9 | --
7 | Inspect circuit 420 for an open. Refer to Electrical Diagnosis, Section 8. Did you find and correct the condition? | -- | Go to Step 9 | Go to Step 8
8 | Replace the PCM.Refer to PCM Replacement/Programming Section 6. Is the replacement complete? | -- | Go to Step 9 | --

9

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

1. Select DTC.
2. Select Clear Info.
3. Operate the vehicle and ensure that the PCM senses ignition volts on the TCC Brake Switch Input for more than 2 seconds.
4. Select Specific DTC. Enter DTC P0719.

Has the test run and passed?

--

System OK

Begin the diagnosis again. Go to Step 1