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 powertrain control module (PCM) senses ignition voltage on the extended travel brake switch signal circuit.
If the PCM senses a 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 2.6 MPH over a 250 millisecond 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 condition is present for 1.5 seconds. |
Action Taken When the DTC Sets
| • | The control module stores the DTC information into memory when the diagnostic runs and fails. |
| • | The malfunction indicator lamp (MIL) will not illuminate. |
| • | The control module records the operating conditions at the time the diagnostic fails. The control module stores this information in the Failure Records. |
| • | The driver information center, if equipped, may display a message. |
Conditions for Clearing the DTC
| • | A current DTC Last Test Failed clears when the diagnostic runs and passes. |
| • | A history DTC clears after 40 consecutive warm-up cycles, if no failures are reported by this or any other non-emission related diagnostic. |
| • | Clear the DTC with a scan tool. |
Diagnostic Aids
Important:
• Remove any debris from the powertrain control module/throttle
actuator control (PCM\TAC) module connector surfaces before servicing the
PCM\TAC module. Inspect the PCM\TAC module connector gaskets when diagnosing/replacing
the modules. Ensure that the gaskets are installed correctly. The gaskets
prevent contaminate intrusion into the PCM\TAC modules. • For any test that requires probing the PCM or probing a component
harness connector, use the connector test adapter kit J 35616
. Using this kit prevents damage
to the harness/component terminals. Refer to
Using Connector Test Adapters
in Wiring Systems. • Test drive the vehicle if you cannot find a problem with the switch
or the circuit. An intermittent condition may be duplicated on a test drive.
| • | This DTC does not set for an open circuit. If the PCM senses the Extended Travel Brake switch is Applied when the brake pedal is actually released a driveability concern may result. |
| • | If a condition is intermittent, refer to Symptoms - Engine Controls . |
Test Description
The numbers below refer to the step numbers on the diagnostic table.
-
An extended travel brake switch signal that indicates Applied when the pedal is actually released may cause a driveability concern.
-
An extended travel brake switch that is not properly adjusted may cause this DTC to set.
-
This step tests for an extended travel brake switch circuit for being shorted to battery voltage.
Step
| Action | Value(s) | Yes | No |
|---|---|---|---|---|
Schematic Reference: Engine Controls Schematics | ||||
1 | Did you perform the Diagnostic System Check-Engine Controls? | -- | Go to Step 2 | |
Does the scan tool display Released? | -- | Go to Step 3 | Go to Step 7 | |
3 |
Does the scan tool display Applied? | -- | Go to Intermittent Conditions | Go to Step 4 |
Inspect the adjustment of the Extended Travel Brake switch. Refer to Stop Lamp Switch Adjustment in Hydraulic Brakes. Was an adjustment necessary? | -- | Go to Step 17 | Go to Step 5 | |
5 |
Does the display indicate Applied? | -- | Go to Step 14 | Go to Step 6 |
Does the voltage measure more than the specified value? | 0.5 V | Go to Step 10 | Go to Step 16 | |
7 |
Does the test lamp illuminate? | -- | Go to Step 8 | Go to Step 11 |
8 |
Does the scan tool display Released? | -- | Go to Step 13 | Go to Step 9 |
9 |
Does the DMM display continuity? | -- | Go to Step 15 | Go to Step 12 |
10 | Repair the short to voltage on the signal circuit. Refer to Wiring Repairs in Wiring Systems. Did you complete the repair? | -- | Go to Step 17 | -- |
11 | Repair the open ignition 1 voltage circuit. Refer to Wiring Repairs in Wiring Systems. Did you complete the repair? | -- | Go to Step 17 | -- |
12 | Repair the open Extended Travel Brake switch signal circuit. Refer to Wiring Repairs in Wiring Systems. Did you complete the repair? | -- | Go to Step 17 | -- |
13 |
Did you find and correct the condition? | -- | Go to Step 17 | Go to Step 14 |
14 | Replace the Extended Travel Brake switch. Refer to Stop Lamp Switch Replacement in Hydraulic Brakes. Did you complete the replacement? | -- | Go to Step 17 | -- |
15 |
Did you find and correct the condition? | -- | Go to Step 17 | Go to Step 16 |
16 | Replace the PCM. Refer to Powertrain Control Module Replacement . Did you complete the replacement? | -- | Go to Step 17 | -- |
17 |
Does the DTC run and pass? | -- | Go to Step 18 | Go to Step 2 |
18 | With a scan tool, observe the stored information, Capture Info. Does the scan tool display any DTCs that you have not diagnosed? | -- | System OK | |
