Cruise Control Diagnosis

DTC P0719

Diagnostic Instructions

* Perform the Diagnostic System Check - Vehicle prior to using this diagnostic procedure. Initial Inspection and Diagnostic Overview
* Strategy Based Diagnosis for an overview of the diagnostic approach.
* Diagnostic Procedure Instructions provides an overview of each diagnostic category.

DTC Descriptor

DTC P0719 00
- Brake Switch Circuit Low Voltage

Circuit/System Description

The cruise release switch is a normally closed switch. The stop lamp switch signal circuit is a normally open switch. When the brake pedal is released, the engine control module (ECM) detects a high voltage signal on the torque converter clutch (TCC) brake switch/cruise control release signal circuit and a low signal voltage signal on the stop lamp switch signal circuit.

Conditions for Running the DTC

* The engine is ON.
* The traction control system or the antilock brake system are not active and have not failed.
* The vehicle has accelerated from 0 km/h (0 mph) to 60 km/h (37 mph) 3 times in one ignition cycle.
* This diagnostic runs continuously once the conditions for running the DTC has been achieved.

Conditions for Setting the DTC

When the brake pedal is released, the ECM detects a low voltage signal on the stop lamp switch signal circuit and a low voltage signal on the TCC brake switch/cruise control release signal circuit.

Action Taken When the DTC Sets

* The ECM stores the DTC information into memory when the diagnostic runs and fails.
* The malfunction indicator lamp (MIL) will not illuminate.
* The ECM records the operating conditions at the time the diagnostic fails. The ECM stores this information in the Failure Records.
* The Cruise Control System is disabled.

Conditions for Clearing the DTC

* A last test failed, or current DTC, clears when the diagnostic runs and does not fail.
* A history DTC will clear after 40 consecutive warm-up cycles, if no failures are reported by this or any other non-emission related diagnostic.
* Use a scan tool in order to clear the DTC.

Diagnostic Aids

In order to avoid a misdiagnosis, inspect for proper adjustment of the cruise control release switch. Refer to Cruise Release Switch Adjustment.

For an intermittent condition, refer to Testing for Intermittent Conditions and Poor Connections in Diagnostic Aids. Component Tests and General Diagnostics

Circuit/System Testing

1. Ignition OFF, disconnect the harness connector at the Stop Lamp/TCC Cruise Release Switch.
2. Ignition ON, test for B+ between the HVAC I/P IGN voltage circuit terminal A and ground.

• If less than the specified voltage, test the voltage circuit for an open/high resistance, or a short to ground.

3. Ignition OFF, connect the harness connector at the Stop Lamp/TCC Switch. Disconnect the harness connector C1 at the ECM.
4. With the Stop Lamp/TCC Switch closed, test for B+ between the TCC Brake Switch/Cruise Control Release Signal circuit and ground.

• If less than the specified voltage, test the signal circuit for an open/high resistance, or a short to ground. If the circuit tests normal, replace the Stop Lamp/TCC Switch.
5. If all circuits test normal, test or replace the ECM.

Repair Instructions

Perform the Diagnostic Repair Verification after completing the diagnostic procedure.

* Stop Lamp Switch Replacement
* Control Module References for ECM replacement, setup, and programming. Verification Tests