Circuit Description
The body control module (BCM) receives a signal from the brake pedal position sensor through the brake pedal position switch signal circuit. The BCM then applies a signal through the stop lamp switch signal circuit to the transmission control module (TCM) and engine control module (ECM).
When the TCM detects an open or short to ground on the stop lamp switch signal circuit during stopping, then 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 OSS DTCs P0722 or P0723. |
| • | No Brake Switch DTC P0724. |
| • | The vehicle speed is greater than 40 km/h (25 mph) for 7 seconds, then 8-40 km/h (5-25 mph) for 5 seconds, then less than 8 km/h (5 mph). |
| • | Continuously 8 times once the previous criteria have been met. |
Conditions for Setting the DTC
The TCM detects an open or short to ground on the stop lamp switch signal circuit when the circuit should be high, B+.
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 records the operating conditions when the Conditions for Setting the DTC are met. The TCM records this information as a Failure Record. |
| • | The TCM stores DTC P0719 in TCM history. |
Conditions for Clearing 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. |
| • | A scan tool can clear the DTC. |
Diagnostic Aids
Important:
• Verify that the brake pedal position sensor is adjusted properly. Refer
toBrake Pedal Position Sensor Calibration in Lighting Systems. • Test drive the vehicle if a switch or circuit condition cannot be located.
An intermittent condition may be duplicated during a test drive.
Test Description
The number below refers to the step number on the diagnostic table.
-
This step determines if the fault is present.
Step | Action | Values | Yes | No | ||||||
|---|---|---|---|---|---|---|---|---|---|---|
1 | Did you perform the Diagnostic System Check - Vehicle? | -- | Go to Step 2 | |||||||
2 |
Does the Stop Lamp Pedal Switch parameter indicate Closed? | -- | Go to Testing for Intermittent Conditions and Poor Connections | Go to Step 3 | ||||||
3 |
Does the test lamp illuminate? | -- | Go to Step 5 | Go to Step 4 | ||||||
4 | Test for the stop lamp switch signal circuit an open or short to ground. Refer to Circuit Testing and Wiring Repairs . Did you find and correct the condition? | -- | Go to Step 7 | Go to Step 6 | ||||||
5 | Replace the TCM. Refer to Control Module References Did you complete the replacement? | -- | Go to Step 7 | -- | ||||||
6 | Replace the BCM. Refer to Control Module References Did you complete the replacement? | -- | Go to Step 7 | -- | ||||||
7 | Perform the following procedure in order to verify the repair:
Has the test run and passed? | -- | Go to Step 8 | Go to Step 2 | ||||||
8 | With the scan tool, observe the stored information, capture info, and DTC Info. Does the scan tool display any DTCs that you have not diagnosed? | -- | System OK |
