GM Service Manual Online
For 1990-2009 cars only

Object Number: 405569  Size: SF
Engine Controls Components
OBD II Symbol Description Notice
EBTCM, Generator Controls, Engine Oil Level Switch
Handling ESD Sensitive Parts Notice
Handling ESD Sensitive Parts Notice

Circuit Description

This diagnostic test functions on the assumption that a brake application causes a sudden decrease in non-drive wheel speed.

The Extended Travel Brake Switch is a normally closed switch. When the Extended Travel Brake Switch is closed, the PCM senses low voltage on the Extended Travel Brake Switch signal circuit.

If the PCM senses low voltage on the Extended Travel Brake Switch signal circuit when the Extended Travel Brake Switch should be open, this DTC sets.

Conditions for Running the DTC

    • The engine speed is greater than 700 RPM.
    • The engine has been operating longer than 2 seconds.
    • The wheel speed must be greater than 30 MPH in order to enable the diagnostic. The diagnostic will disable when the wheel speed is below 10 MPH.
    • The vehicle speed is decreasing at a rate greater than 10.4 MPH over a one second period.

Conditions for Setting the DTC

    • The PCM detects voltage on the Extended Travel Brake Switch circuit when the Extended Travel Brake Switch should be open.
    • The above conditions are present for 1.5 seconds.

Action Taken When the DTC Sets

The PCM stores conditions which were present when the DTC set as Failure Records only. This information will not be stored as Freeze Frame Records.

Conditions for Clearing the MIL/DTC

    • The DTC becomes history when the conditions for setting the DTC are no longer present.
    • The history DTC clears after 40 malfunction free warm-up cycles.
    • The PCM receives a clear code command from the scan tool.

Diagnostic Aids

Important: Remove any debris from the component module connector surfaces before servicing the component module. Inspect the component module connector gaskets when diagnosing/replacing the modules. Ensure that the gaskets are installed correctly. The gaskets prevent contaminate intrusion into the components modules.

In order to adjust the Extended Travel Brake Switch perform the following:

  1. With the brake pedal depressed, insert the Brake Lamp Switch into the retainer until the switch body seats in the retainer. You can hear clicks as you push the threaded portion of the switch through the retainer.
  2. Slowly pull the brake pedal fully rearward against the stop until you can no longer hear the clicks.

Test Description

The numbers below refer to the step numbers on the diagnostic table.

  1. This step determines if the fault is present.

  2. This step checks for a Extended Travel Brake Switch circuit for being shorted to B+.

  3. This DTC will not report a pass. The scan tool status for this DTC will never report a pass. The scan tool will only display when the diagnostic fails. The repair is not complete if the scan tool indicates that the diagnostic ran and failed.

Step

Action

Value(s)

Yes

No

1

Did you perform the Powertrain On-Board Diagnostic (OBD) System Check?

--

Go to Step 2

Go to Powertrain On Board Diagnostic (OBD) System Check

2

  1. Install a scan tool.
  2. Start the engine.
  3. Monitor the Extended Travel Brake switch using the scan tool.
  4. Depress the brake pedal approximately half-way.

Does the display indicate Applied?

--

Go to Diagnostic Aids

Go to Step 3

3

Check the adjustment of the extended travel brake switch. Refer to Diagnostic Aids .

Was an adjustment necessary?

--

Go to Step 9

Go to Step 4

4

  1. Turn OFF the ignition.
  2. Disconnect the extended travel brake switch.
  3. Turn ON the ignition with the engine OFF.
  4. Monitor the Extended Travel Brake switch using the scan tool.

Does the display indicate Applied?

--

Go to Step 7

Go to Step 5

5

  1. Turn OFF the ignition.
  2. Disconnect the PCM connector C1 located on the same side as the manufacturer's logo. Refer to Powertrain Control Module Replacement/Programming .
  3. Turn ON the ignition with the engine OFF.
  4. Install a brown connector from the connector test adaptor kit J 35616 into the extended brake travel switch signal circuit.
  5. Measure the voltage on the extended travel brake switch signal circuit using a DMM.

Is the voltage greater than the specified value?

0.5V

Go to Step 6

Go to Step 8

6

Repair the short to voltage on the extended travel brake switch signal circuit. Refer to Wiring Repairs .

Is the action complete?

--

Go to Step 9

--

7

Replace the extended travel brake switch. Refer to Stop Lamp Switch Replacement .

Is the action complete?

--

Go to Step 9

--

8

Important:: Program the replacement PCM.

Refer to Powertrain Control Module Replacement/Programming .

Replace the PCM.

Is the action complete?

--

Go to Step 9

--

9

  1. Select the Diagnostic Trouble Codes (DTC) option and the Clear DTC Information option using the scan tool.
  2. Idle the engine at the normal operating temperature.
  3. Select the Specific DTC option under the Diagnostic Trouble Code (DTC) option using a scan tool.
  4. Operate vehicle within the Conditions for Running this DTC as specified in the supporting text (if applicable).

Does the scan tool indicate that this test failed?

--

Go to Step 2

Go to Step 10

10

Select the Capture Info option and the Review Info option using the scan tool.

Are any DTCs displayed that you have not diagnosed?

--

Go to applicable DTC table

System OK