P1574
DTC P1574
CIRCUIT 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 powertrain control module (PCM) 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.
DTC DESCRIPTOR
This diagnostic procedure supports the following DTC:
DTC P1574 Stoplamp Switch 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 pressed, the PCM 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 PCM stores the DTC information into memory when the diagnostic runs and fails.
- The malfunction indicator lamp (MIL) will not illuminate.
- The PCM records the operating conditions at the time the diagnostic fails. The PCM 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, perform the following:
- Inspect for proper operation of the stop lamps.
- Inspect for proper adjustment of the stop lamps.
- For an intermittent condition, refer to Testing for Intermittent Conditions and Poor Connections in Diagnostic Aids.
TEST
