Circuit Description
The brake switch indicates brake pedal status to the Powertrain Control Module (PCM). The normally-Closed brake switch supplies battery voltage on circuit 420 to the PCM. Applying the brake pedal opens the switch, interrupting voltage to the PCM. Releasing the brake pedal resumes voltage to the PCM. When the PCM senses 0 volts at the brake switch input, the PCM de-energizes the Torque Converter Clutch Solenoid Valve.
When the PCM detects an open brake switch (stuck ON) during accelerations, then DTC P0719 sets. DTC P0719 is a type D DTC.
Conditions for Setting the DTC
DTC P0719 sets if the PCM detects an open brake switch or circuit (0 volts) during vehicle acceleration and the following conditions occur six consecutive times:
| • | The vehicle speed is less than 8 km/h (5 mph); |
| • | then, the vehicle speed is 8-32 km/h (5-20 mph) for 4 seconds; |
| • | then, the vehicle speed is greater than 32 km/h (20 mph) for 6 seconds. |
Action Taken When the DTC Sets
| • | The PCM does not illuminate the Malfunction Indicator Lamp (MIL). |
| • | DTC P0719 is stored in the PCM history. |
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
| • | Ask about the customer's driving habits. Ask about unusual traffic conditions, and stop-and-go driving. |
| • | Inspect the brake switch for proper adjustment. |
| • | Inspect the wiring for poor electrical connections at the PCM. Inspect the wiring for poor electrical connections at the brake switch connector and all other circuit connecting points. 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 |
| - | Moisture intrusion |
| - | Corrosion |
| • | 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.
-
Disconnecting the brake switch connector, jumping the circuit, and observing a status change, isolates the brake switch as the source of the DTC.
-
If circuit 439 shorts to ground, the ERLS fuse opens.
-
If the brake switch is properly adjusted, then the brake switch must be replaced.
-
Replace the PCM only after you have completed the preceding diagnostic steps.
Step | Action | Value(s) | Yes | No | ||||||
|---|---|---|---|---|---|---|---|---|---|---|
1 | Was the Powertrain On-Board Diagnostic (OBD) System Check performed? | -- | ||||||||
Important: Before clearing the DTC(s), 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. Did the brake switch status change from Open to Close? | -- | |||||||||
Refer to Troubleshooting Procedures in the Electrical Diagnosis Section. Is the fuse open? | -- | |||||||||
Inspect circuit 439 for a short to ground. Refer to Troubleshooting Procedures in the Electrical Diagnosis Section. Did you find and correct the condition? | -- | -- | ||||||||
Inspect the brake switch for proper adjustment. Refer to Stoplamp Switch Adjustment in the General Brakes Section. Did you find and correct the condition? | -- | |||||||||
6 | Replace the brake switch. Refer to Stoplamp Switch in the General Brakes Section. Is the replacement complete? | -- | -- | |||||||
7 | Inspect circuit 420 for an open. Refer to Troubleshooting Procedures in the Electrical Diagnosis Section. Did you find and correct the condition? | -- | ||||||||
8 | Replace the PCM. Refer to Powertrain Control Module/EEPROM Replacement/Programming . Is the replacement complete? | -- | -- | |||||||
9 | In order to verify your repair, perform the following procedure:
Has the test run and passed? | -- | System OK |
