Diagnostic Instructions
| • | Perform the Diagnostic System Check - Vehicle prior to using this diagnostic procedure. |
| • | Review Strategy Based Diagnosis for an overview of the diagnostic approach. |
| • | Diagnostic Procedure Instructions provides an overview of each diagnostic category. |
DTC Descriptor
DTC P0571: Cruise Control Brake Switch CircuitDiagnostic Fault Information
Circuit | Short to Ground | Open/High Resistance | Short to Voltage | Signal Performance |
|---|---|---|---|---|
B+ | P1574 | P1574 | -- | -- |
Stop Lamp Switch Signal | P0571 | P0571 | P0571 | -- |
Stop Lamp Switch Control | P0571 | P0571 | -- | -- |
TCC Brake Switch/Cruise Control Release Signal | P1574 | P1574 | P1574 | -- |
Circuit/System Description
The brake switch/cruise control release switch and the stop lamp switch are incorporated into an assembly and are mounted to the brake pedal bracket. When the brake pedal is pressed, the normally closed brake switch/cruise control release switch opens and the normally open stoplamp switch closes. This creates a low signal voltage on the brake switch/cruise control release switch signal circuit and a high signal voltage on the stop lamp switch signal circuit.
Conditions for Running the DTC
| • | The engine speed is greater than 700 RPM. |
| • | The traction control system or the antilock brake system are not active and have not failed. |
| • | The vehicle speed is greater than 48 km/h (30 mph). |
| • | The diagnostic will disable when the wheel speed is less than 16 km/h (10 mph). |
Conditions for Setting the DTC
| • | The engine control module (ECM)/ powertrain control module (PCM) detects a transition on the TCC brake/cruise release circuit without a corresponding transition of the stoplamp switch circuit. |
| • | The above condition is present for greater than 1.5 seconds. |
Actions Taken When the DTC Sets
| • | The malfunction indicator lamp (MIL) will not illuminate. |
| • | The cruise control system is disabled. |
Conditions for Clearing the DTC
| • | The condition responsible for setting the DTC no longer exists. |
| • | A history DTC will clear after 40 malfunction-free ignition cycles have occurred. |
Diagnostic Aids
Verify the stop lamps operate properly. Refer to Exterior Lighting Systems Description and Operation.
Reference Information
Schematic Reference
Connector End View Reference
Description and Operation
Cruise Control Description and Operation
Electrical Information Reference
Scan Tool Reference
Control Module References for scan tool information
Circuit/System Verification
Ignition ON, observe the Stoplamp Pedal Switch parameter while applying and releasing the brake pedal. The reading should change between Applied/Released, and all brake lights should turn ON and OFF.
Circuit/System Testing
- Ignition OFF, disconnect the stop lamp switch.
- Ignition ON, test for B+ between the appropriate B+ circuit terminal listed below and ground.
- Ignition OFF, reconnect the stop lamp switch. Ignition ON, verify the Stoplamp Pedal Switch parameter displays Released.
- Apply the brake pedal. Verify the Stoplamp Pedal Switch parameter displays Applied.
- If all circuit tests normal, replace the ECM or PCM.
| • | B+ circuit terminals C and E (with JE3/C4 or JE4) |
| • | B+ circuit terminals B and D (with JE3/C5/C6/C7) |
| ⇒ | If less than the specified value, test the B+ circuit for a short to ground or an open/high resistance. |
| ⇒ | If the parameter displays Applied, test the signal circuit terminal F (with JE3/C4 or JE4) or terminal A (with JE3/C5/C6/C7) for a short to voltage. If the circuit tests normal, test or replace the stop lamp switch. |
| ⇒ | If the parameter displays Released, test the signal circuit terminal F (with JE3/C4 or JE4) or terminal A (with JE3/C5/C6/C7) for a short to ground or an open/high resistance. If the circuit tests normal, test or replace the stoplamp switch. |
Component Testing
- Ignition OFF, disconnect the harness connector at the stop lamp switch.
- Test for infinite resistance between the appropriate switch terminals listed below.
- Depress the brake pedal. Test for less than 1 ohm between the appropriate switch terminals listed below.
| • | terminals E and F (with JE3/C4 or JE4) |
| • | terminals B and A (with JE3/C5/C6/C7) |
| ⇒ | If not the specified value, replace the stop lamp switch. |
| • | terminals E and F (with JE3/C4 or JE4) |
| • | terminals B and A (with JE3/C5/C6/C7) |
| ⇒ | If not the specified value, replace the stop lamp switch. |
Repair Instructions
Perform the Diagnostic Repair Verification after completing the diagnostic procedure.
| • | Control Module References for ECM or PCM module replacement, setup, and programming |
