When an ignition key is inserted into the ignition lock cylinder and switch to 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 body control module (BCM). The BCM then compares this value to a value stored in memory, learned key code. If the value is correct the BCM sends the fuel enable password via the serial data circuit to the powertrain control module (PCM).
This diagnostic procedure supports the following DTC:
DTC B2945 Security System Sensor Power Circuit
The ignition is switched from ON to OFF.
If the BCM senses the security system sensor supply circuit is short to battery positive when the ignition is in the OFF position DTC B2945 will be set as a current DTC. If the DTC is current when the ignition is switched to the ON position the DTC will become a history DTC.
With the ignition ON DTC B2945 can only be retrieved as a history DTC. There will be no symptom to the driver of a failure.
• | The BCM clears the history status of the DTC after 100 fault-free ignition cycles. |
• | The DTC can be cleared by using a scan tool. |
A security system sensor supply circuit that is shorted to battery positive could cause an open in the theft deterrent exciter module which will cause DTC B3055. If you were sent to this diagnostics from DTC B3055 table ensure you complete DTC B3055 diagnostics after DTC B2945 condition has been corrected.
The number below refers to the step number on the diagnostic table.
Step | Action | Yes | No |
---|---|---|---|
Schematic Reference: Immobilizer Schematics Connector End View Reference: Immobilizer Connector End Views | |||
1 | Did you perform the Diagnostic System Check - Vehicle? | Go to Step 2 | |
Is DTC B2945 set as current? | Go to Step 3 | Go to Testing for Intermittent Conditions and Poor Connections | |
3 | Inspect the security system sensor supply voltage circuit for a short to battery. Refer to Circuit Testing and Wiring Repairs . Did you find and correct the condition? | Go to Step 4 | Go to Testing for Intermittent Conditions and Poor Connections |
4 |
Does the DTC reset? | Go to Step 2 | System OK |