Diagnostic Instructions
| • | Perform the Diagnostic System Check - Vehicle prior to using this diagnostic procedure. |
| • | Review Strategy Based Diagnosis for an overview of the diagnostic approach. |
| • | Diagnostic Procedure Instructions provides an overview of each diagnostic category. |
DTC Descriptor
DTC B3055: No Transponder Modulation or No TransponderDiagnostic Fault Information
Circuit | Short to Ground | Open/High Resistance | Short to Voltage | Signal Performance |
|---|---|---|---|---|
Security System Sensor Supply Voltage | B3055 | B3055 | B2945 | -- |
Security System Sensor Low Reference | -- | B3055 | B3055 | -- |
Ground | -- | B3055 | B3055 | -- |
Circuit/System Description
When the ignition is switched to the ON position, the body control module (BCM) supplies 12 volts to the theft deterrent exciter module. The BCM also provides a low reference for the exciter. With the voltage supplied to the exciter, the transponder embedded in the head of the key is energized by the exciter coils surrounding the ignition lock cylinder. The energized transponder transmits a signal that contains its unique value, which is received by the BCM. The BCM then compares this value to a value stored in memory, the learned key code. If the value received matches the stored value, the BCM sends the fuel enable password to the engine control module/powertrain control module (ECM/PCM) via serial data.
Conditions for Running the DTC
Ignition is in the Accessory or Run position.
Conditions for Setting the DTC
The BCM is unable to measure the ignition key transponder value.
Action Taken When the DTC Sets
| • | Vehicle starting will be disabled. |
| • | The security indicator will be illuminated. |
Conditions for Clearing the DTC
| • | A current DTC will be cleared when the BCM detects a valid transponder value from the ignition key. |
| • | A history DTC will be cleared after 100 malfunction-free ignition cycles. |
Reference Information
Schematic Reference
Connector End View Reference
Description and Operation
Immobilizer Description and Operation
Electrical Information Reference
Scan Tool Reference
Control Module References for scan tool information
Circuit/System Verification
Important: When using this diagnostic, more than one vehicle key is required to ensure proper diagnosis. If more than one key is not available at the time of service, contact the customer and ask if any other keys can be provided for service. If unavailable, a new second key can be created.
- Inspect all available vehicle keys that they are correct vehicle keys.
- While viewing the scan tool TDM Transponder Key parameter, turn ON the ignition with each of the available vehicle keys. The parameter should read Present with all available keys.
| ⇒ | If not a correct vehicle key, replace the key. |
| ⇒ | If only one key results in the parameter reading Not Present, replace the appropriate key. |
| ⇒ | If all available keys result in the parameter reading Not Present, refer to Exciter Circuit Malfunction. |
Circuit/System Testing
Exciter Circuit Malfunction
- Ignition OFF, disconnect the harness connector at the theft deterrent exciter.
- Ignition OFF, test for less than 10 ohms of resistance between the low reference circuit terminal E and ground.
- Test for less than 10 ohms of resistance between the ground circuit terminal B and ground.
- Ignition ON, test for B+ between the B+ circuit terminal A and ground.
- If all circuits test normal, replace the theft deterrent exciter.
| ⇒ | If greater than the specified range test the low reference circuit for an open/high resistance. If the circuit tests normal, replace the BCM. |
| ⇒ | If greater than the specified range test the ground circuit for an open/high resistance. |
| ⇒ | If not the specified value, test the B+ circuit for a short to ground or an open/high resistance. If the circuit tests normal, replace the BCM. |
Repair Instructions
Perform the Diagnostic Repair Verification after completing the diagnostic procedure.
| • | Control Module References for BCM replacement, setup, and programming |
