GM Service Manual Online
For 1990-2009 cars only
Makes 🢒 Cadillac 🢒 2000 🢒 Eldorado 🢒 Brakes 🢒 Antilock Brake System 🢒 DTC C1297 PCM Indicated Brake Extended Travel Switch Failure

Object Number: 592762 Size: MF
ABS Components
PWR, GND, Stoplamp Switch, Solenoid Valves, and Pump Motor
Handling ESD Sensitive Parts Notice
Battery Feeds
Power, Ground, and Class 2 (1 of 2)

Circuit Description

The extended travel brake switch is used by the EBCM to determine if the driver has pressed the brake pedal far enough to initiate moderate braking, as opposed to merely brushing or tapping the pedal. The PCM sends this information to the EBCM via serial data messages.

Conditions for Running the DTC

The ignition is ON.

Conditions for Setting the DTC

The PCM detects an extended travel brake switch failure. The PCM also sets DTC P1575.

Action Taken When the DTC Sets
    • The EBCM disables the VSES for the duration of the ignition cycle.
    • The DIC displays the SERVICE STABILITY SYS message.
    • The ABS/TCS remains functional.

Conditions for Clearing the DTC
    • The condition for the DTC is no longer present (the DTC is not current) and you used the scan tool Clear DTC function.
    • The condition for the DTC is no longer present (the DTC is not current) and you used the On-Board Diagnostics Clear DTC function.
    • The EBCM automatically clears the history DTC when a current DTC is not detected in 50 consecutive drive cycles.

Diagnostic Aids

If the extended travel brake switch is not properly adjusted, the driver may experience longer VSES brake pedal pulsations before normal brake pedal feel is returned. The VSES brake pedal pulsation is different than the ABS brake pedal pulsation. The VSES brake pedal pulsation has a much higher frequency and less pedal travel fluctuation.

Step

Action

Value(s)

Yes

No

1

Did you perform the ABS Diagnostic System Check?

--

Go to Step 2

Go to Diagnostic System Check - ABS

2
  1. Turn OFF the ignition.
  2. Install a scan tool.
  3. Turn ON the ignition, with the engine OFF.
  4. Use the scan tool in order to read the powertrain control module (PCM) DTCs.

Is DTC P1575 set as a current DTC?

--

Go to DTC P1575 Extended Travel Brake Switch Circuit in Engine Controls - 4.6L

Go to Step 3

3
  1. Turn ON the ignition, with the engine OFF.
  2. Observe the Extended Travel Brake Switch parameter in the Delco/Bosch ABS/TCS ICCS (if equipped) data list.
  3. Step on and off the brake pedal with enough force in order to simulate a hard braking condition. As the brake pedal is pressed and released, the scan tool should read Applied and Released.
  4. Use a tape measure in order to measure the distance that the brake pedal travels for the scan tool to read Applied.

Is the distance within the specified range?

2.5-3.3 cm (1.0-1.3 in)

Go to Step 5

Go to Step 4

4

Adjust or repair the extended travel brake switch as necessary. Refer to Stop Lamp Switch Replacement or Stop Lamp Switch Adjustment in Hydraulic Brakes.

Did you complete the repair?

--

Go to Step 5

--

5
  1. Use the scan tool in order to clear the DTCs.
  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