P1574
DTC P1574
CIRCUIT DESCRIPTION
The stop lamp switch is a normally open switch. When the stop lamp switch is closed and the brake pedal is pressed, then the engine control module (ECM) senses ignition voltage on the Stop Lamp Switch Signal circuit. If the ECM senses voltage on the TCC brake switch/cruise control release signal circuit when the torque converter clutch (TCC)/brake switch should be open, this DTC sets.
CONDITIONS FOR RUNNING THE DTC
- Vehicle has cycled from 0-60 km/h (0-37 mph) 3 times in 1 ignition cycle.
- Continuous once the previous criteria have been met.
CONDITIONS FOR SETTING THE DTC
The ECM does not detect a voltage state change on the stop lamp switch signal circuit after three stops. A high or low condition will set this code.
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.
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
IMPORTANT:
- Verify that the stop lamp switch is adjusted properly. Refer to Stop Lamp Switch Adjustment in Lighting Systems.
- If any of the stop lamps are not operating correctly refer to Stop Lamps Inoperative 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.
- For an intermittent, refer to Testing for Intermittent Conditions and Poor Connections in Diagnostic Aids.
TEST DESCRIPTION
Steps 1 - 14:
Step 15:
The number below refers to the step number on the diagnostic table.
2. This step determines if the fault is present.