2001 Chevrolet/Geo Camaro  

DTC P1574

Circuit Description

This diagnostic test functions on the assumption that sudden decrease in a non-drive, wheel speed must be caused by a brake application. Non-drive wheel speed and stoplamp switch status are supplied to the PCM through serial data from the Electronic Brake Control Module (EBCM). If there is a 4 km/h (2.5 mph) or greater decrease of non-drive wheel speed in 0.4 seconds and a transition of the TCC or extended travel contacts of the TCC brake switch without a transition of the stop lamp brake switch, DTC P1574 is set.

Conditions for Running the DTC
Conditions for Setting the DTC

A 4.0 km/h (2.5 mph) or greater decrease in non-drive wheel speed in 0.4 second and extended travel brake switch or TCC brake switch indicating brakes applied and no transition noticed in the stoplamp contacts of the stop lamp switch.

Action Taken When the DTC Sets

PCM will set the stoplamp switch status to not applied.

Conditions for Clearing the DTC
Diagnostic Aids

DTC P1574 indicates the stoplamp switch signal to the EBCM or the EBCM's ability to send the stop lamp switch signal to the PCM has failed. Refer to ABS/TCS DTCs for diagnosis of the stoplamp switch signal and the EBCM.






Did you perform the Cruise Control Diagnostic System Check?

Go to Step 2

Go to Diagnostic System Check - Cruise Control


  1. Connect the scan tool.
  2. Turn ON the ignition, with the engine OFF.
  3. Retrieve the DTCs from the EBCM.

Are there any DTC's that begin with a "C" also set?

Go to Diagnostic Trouble Code (DTC) List

Go to Step 3


Repair the short to voltage on the stop lamp switch signal circuit.

Did you find and correct the condition?

Go to Step 4



  1. Use the scan tool to clear the DTC (s).
  2. Operate the vehicle within the conditions for Running the DTC as specified in the supporting text.

Does the DTC reset?

Go to Step 2

System OK