B2955
DTC B2955
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 Descriptor
DTC B2955 00
-
Security Sensor Data Circuit Malfunction
Diagnostic Fault Information
Circuit/System Description
When a keyless entry transmitter is inserted into the transmitter pocket/slot and the ignition mode switch is pressed, the transponder embedded in the transmitter is energized by the immobilizer antenna exciter coil. The transponder transmits a signal to the body control module (BCM). The BCM then compares this value to a value stored in memory. If the value is correct, the BCM will send the prerelease password via the serial data circuit to the engine control module (ECM). If the learned key code does not match or a transponder value is not received, the BCM will send the start disable password to the ECM.
Conditions for Running the DTC
Vehicle is ON or in Service Mode.
Conditions for Setting the DTC
The BCM detects a circuit fault on the immobilizer antenna circuits.
Action Taken When the DTC Sets
* Vehicle starting will be disabled.
* The security indicator in the instrument cluster will be illuminated. A service message will be displayed in the driver information center.
Conditions for Clearing the DTC
* A current DTC will be cleared when the condition for setting the DTC are no longer present.
* A history DTC will be cleared after 100 malfunction-free ignition cycles or when a scan tool is used to clear DTCs.
Reference Information
Schematic Reference
Immobilizer Schematics Immobilizer Schematics
Connector End View Reference
Component Connector End Views Hybrid/EV Battery Pack X1
Description and Operation
Immobilizer Description and Operation Immobilizer
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
Scan Tool Reference
Control Module References Programming and Relearning for scan tool information
Circuit/System Testing
1. Vehicle OFF and all vehicle systems OFF, disconnect the harness connector at the K89 immobilizer control module. It may take up to 2 minutes for all vehicle systems to power down.
2. Test for less than 30 ohms between the low reference circuit terminal 1 and ground.
• If 30 ohms or greater
1. Vehicle OFF, disconnect the harness connector at the K9 BCM.
2. Test for less than 2 ohms in the low reference circuit end to end.
• If 2 ohms or greater, repair the open/high resistance in the circuit.
• If less than 2 ohms, replace the K9 BCM.
• If less than 30 ohms
3. Connect a test lamp between the B+ circuit terminal 3 and ground.
4. Verify the test lamp illuminates or flashes for three seconds after ignition mode switch is pressed.
• If the test lamp does not illuminate
1. Vehicle OFF, disconnect the harness connector at the K9 BCM.
2. Test for infinite resistance between the B+ circuit and ground.
• If less than infinite resistance, repair the short to ground on the circuit.
• If infinite resistance
3. Test for less than 2 ohms in the B+ circuit end to end.
• If 2 ohms or greater, repair the open/high resistance in the circuit.
• If less than 2 ohms, replace the K9 BCM.
• If the test lamp illuminates
5. Vehicle in Service Mode.
6. Test for 12-13 V between the serial data circuit terminal 2 and ground.
• If less than 12 V
1. Vehicle OFF, disconnect the harness connector at the K9 BCM.
2. Test for infinite resistance between the serial data circuit and ground.
• If less than infinite resistance, repair the short to ground on the circuit.
• If infinite resistance
3. Test for less than 2 ohms in the serial data circuit end to end.
• If 2 ohms or greater, repair the open/high resistance in the circuit.
• If less than 2 ohms, replace the K9 BCM.
• If greater than 13 V
1. Vehicle OFF, disconnect the harness connector at the K9 BCM, vehicle ON.
2. Test for less than 1 V between the signal circuit and ground.
• If 1 V or greater, repair the short to voltage on the circuit.
• If less than 1 V, replace the K9 BCM.
• If within 12-13 V
7. Replace the K89 immobilizer control module.
8. Verify DTC B2955 is not set.
• If DTC B2955 is set
Replace the K9 BCM.
• If DTC B2955 is not set or is set as history
9. All OK.
Repair Instructions
Perform the Diagnostic Repair Verification Verification Tests after completing the diagnostic procedure.
* Theft Deterrent Module Replacement Service and Repair
* Control Module References Programming and Relearning for BCM replacement, setup, and programming