P081B

DTC P081A or P081B

Diagnostic Instructions

* Perform the Diagnostic System Check - Vehicle (Diagnostic System Check - Vehicle) prior to using this diagnostic procedure.
* Review Strategy Based Diagnosis (Strategy Based Diagnosis) for an overview of the diagnostic approach.
* Diagnostic Procedure Instructions (Diagnostic Procedure Instructions)provides an overview of each diagnostic category.

DTC Descriptors
DTC P081A
- Brake Transmission Shift Interlock Solenoid Actuator - Short to Ground/Open

DTC P081B
- Brake Transmission Shift Interlock Solenoid Actuator - Short to Voltage

Diagnostic Fault Information





Circuit/System Description

The transmission range switch is an integral part of the transmission control module (TCM). As the gear range selector lever is moved, the state of the starter inhibit circuit may change, causing the circuit to open or close. An open circuit indicates a drive range and a low voltage signal, 0 V, at the body control module (BCM). A closed circuit indicates PARK or NEUTRAL and a high voltage, 12 V, signal at the BCM. The BCM uses the starter inhibit circuit status from the TCM in order to enable starter operation.

Conditions for Running the DTC

P081A, P081B
* The ignition voltage is 9.0-18.0 V.
* The transmission is not in emergency mode.

Conditions for Setting the DTC

P081A
* Start lock output is "On" and start lock monitor signal indicates "Off" for more than 10 ms.
* After consecutive 2 times of above detection.

P081B
* Start lock output is "Off" and start lock monitor signal indicates "On" for more than 100 ms.
* After consecutive 2 times of above detection.

Action Taken When the DTC Sets

P081A
* DTCs P081A and P081B are Type D DTCs.
* No engine start possible.

Conditions for Clearing the DTC

P081A
* DTCs P081A and P081B are Type D DTCs.
* Start lock output is "On" and start lock monitor signal indicates "On" and/or start lock output is "Off" and start lock monitor signal indicates "Off" for more than 1 s.

Reference Information
Schematic Reference

Automatic Transmission Controls Schematics (AF40-6 - Automatic Transmission)
Connector End View Reference

Component Connector End Views (Connector End Views By Name)
Electrical Information Reference

* Circuit Testing (Circuit Testing)
* Connector Repairs (Connector Repairs)
* Testing for Intermittent Conditions and Poor Connections (Testing for Intermittent Conditions and Poor Connections)
* Wiring Repairs (Wiring Repairs)

Description and Operation

Transmission Component and System Description (Transmission Component and System Description)
DTC Type Reference

Powertrain Diagnostic Trouble Code (DTC) Type Definitions (Powertrain Diagnostic Trouble Code (DTC) Type Definitions)
Scan Tool Reference

Control Module References (Programming and Relearning)for scan tool information

Circuit/System Verification

1. The engine has to start in range position P and N.
2. The engine must not start in all other range positions.

Circuit/System Testing

Dynamic Test

Ignition ON, observe the scan tool Transmission Range Switch parameter while selecting each transmission range: P, R, N, D. Each selected transmission range should correspond to the correct scan tool parameter displayed.

If not equal to the specified range, test the starter inhibit circuit for a short to ground, an open/high resistance, or a short to voltage. If the circuit test normal, replace the TCM.

Component Testing

Static Test
1. Ignition OFF, remove the wiring harness connector from K71 Transmission Control Module.
2. Test the starter inhibit circuit 5 X1 for a short to ground, an open/high resistance, or a short to voltage.

• If the circuit tests normal, replace the K71 Transmission Control Module.

3. Verify the DTC does not reset. If the DTC resets, replace the K9 Body Control Module.

Repair Instructions

Perform the Diagnostic Repair Verification (Verification Tests) after completing the diagnostic procedure.

* Refer to Control Module References (Programming and Relearning) for BCM, TCM replacement, setup and programming.
* Perform the Transmission Adaptive Functions (Transmission Adaptive Functions).