4T40-E / 4T45-E Automatic Transaxle

DTC P0719





Circuit Description with 4T40-E / 4T45-E Automatic Transaxle
The stop lamp switch indicates brake pedal status to the transmission control module (TCM). The normally-open stop lamp switch supplies ignition voltage to the TCM. Applying the brake pedal closes the switch, supplying voltage to the TCM. Releasing the brake pedal interrupts voltage to the TCM. When the TCM senses ignition voltage at the stop lamp switch input, the TCM de-energizes the torque converter clutch (TCC) solenoid valve.

When the TCM detects an open stop lamp switch, stuck OFF, during decelerations, DTC P0719 sets. DTC P0719 is a type C DTC.

DTC Descriptor
This diagnostic procedure supports the following DTC:
DTC P0719 Brake Switch Circuit Low Voltage

Conditions for Running the DTC
No VSS DTCs P0722 or P0723.

Conditions for Setting the DTC
DTC P0719 sets if the TCM detects an open stop lamp switch or circuit for 15 minutes, 0 volts, during vehicle deceleration and the following conditions occur 8 times:
1. The vehicle speed is greater than 32 km/h (20 mph) for 6 seconds;
2. then, the vehicle speed is 8 - 32 km/h (5 - 20 mph) for 2-6 seconds;
3. then, the vehicle speed is less than 8 km/h (5 mph).

Action Taken When the DTC Sets
^ The TCM does not request the engine control module (ECM) to illuminate the malfunction indicator lamp (MIL).
^ The TCM disregards the stop lamp switch input for TCC scheduling. The TCM then uses throttle position and vehicle speed inputs to determine TCC application and release. Use of these inputs may result in a noticeable harsh apply or abrupt release of the TCC.
^ The TCM records the operating conditions when the Conditions for Setting the DTC are met. The TCM stores this information as Failure Records.
^ The TCM stores DTC P0719 in TCM history.

Conditions for Clearing the DTC
^ A scan tool can clear the DTC.
^ The TCM clears the DTC from TCM history if the vehicle completes 40 warm-up cycles without a non-emission-related diagnostic fault occurring.
^ The TCM cancels the DTC default actions when the fault no longer exists and the DTC passes.

Test Description








The numbers below refer to the step numbers on the diagnostic table.
2. Disconnecting the stop lamp switch connector, jumping the circuit, and observing a status change, isolates the stop lamp switch as the source of the DTC.
3. If the ignition 1 voltage circuit shorts to ground, the BRAKE fuse opens.
5. If the stop lamp switch is properly adjusted, then the stop lamp switch must be replaced.
8. Replace the TCM only after you have completed the preceding diagnostic steps.