Cruise Control Diagnosis

DTC P0724

DTC Descriptor

DTC P0724 00

- Brake Switch Circuit High 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 high voltage signal on the stop lamp switch signal circuit and a high 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 Switch.
2. Ignition ON, connect a test lamp between the TCC Brake Switch/Cruise Control Release Signal circuit terminal B and ground.

• If the test lamp illuminates, test the signal circuit for a short to voltage. If the circuit tests normal, replace the ECM.
• If the test lamp does not illuminate, replace the stop lamp/TCC switch.

Repair Instructions

Perform the Diagnostic Repair Verification after completing the diagnostic procedure. Verification Tests

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