DTC Descriptor
DTC B3055: No Transponder Modulation or No TransponderDiagnostic Fault Information
Perform the Diagnostic System Check - Vehicle prior to using this diagnostic procedure.
Circuit/System Description
When an ignition key is inserted into the ignition lock cylinder and the ignition is switched ON, 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 theft deterrent module (TDM). The TDM then compares this value to a value stored in memory. This stored value is the learned key code. If the value is correct, the TDM will send the pre-release password via the serial data circuit to the engine control module (ECM). If either the transponders unique value or the calculation to the challenge is incorrect, the TDM will send the start disable password to the ECM.
Conditions for Running the DTC
Ignition is in the Accessory or Run position.
Conditions for Setting the DTC
The TDM 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 TDM detects a valid transponder value from the ignition key. |
| • | 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
Theft Deterrent System Schematics
Connector End View Reference
Theft Deterrent System Connector End Views
Description and Operation
Vehicle Theft Deterrent (VTD) Description and Operation
Electrical Information Reference
Scan Tool Reference
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 Transponder Key parameter, turn ON the ignition with each of the available vehicle keys. The parameter should read Present with all vehicle keys.
| ⇒ | If not a correct vehicle key, replace the key. |
| ⇒ | If only one vehicle key results in the parameter reading Not Present, replace the affected key. |
| ⇒ | If all available keys result in the parameter reading Not Present, replace the TDM. |
Repair Instructions
Perform the Diagnostic Repair Verification after completing the diagnostic procedure.
| • | Control Module References for theft deterrent module replacement, setup, and programming |
