GM Service Manual Online
For 1990-2009 cars only
Makes 🢒 Cadillac 🢒 2002 🢒 Eldorado 🢒 Brakes 🢒 Antilock Brake System 🢒 DTC C1297

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 System 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

Values

Yes

No

Schematic Reference: Antilock Brake System Schematics

1

Did you perform the ABS Diagnostic System Check?

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Go to Step 2

Go to Diagnostic System Check - ABS

2
  1. Install a scan tool.
  2. Turn ON the ignition, with the engine OFF.
  3. Select the display DTCs function on the scan tool for the powertrain control module (PCM).

Does the scan tool display DTC P1575?

--

Go to DTC P1575 in Cruise Control

Go to Step 3

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

Does the distance measure within the specified range?

2.5-3.3 cm (1.0-1.3 in)

Go to Testing for Intermittent Conditions and Poor Connections in Wiring Systems

Go to Step 4

4

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

Did you complete the repair?

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Go to Step 5

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5

Operate the system in order to verify the repair.

Did you correct the condition?

--

System OK

Go to Step 2