B1424

DTC B1424

Diagnostic Instructions

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

DTC Descriptor

DTC B1424 00
- Device Voltage Low - Theft Deterrent Module

Diagnostic Fault Information






Circuit/System Description

The Passkey III+ theft deterrent module (TDM) monitors the battery positive (B+) voltage available to it. If the voltage at the TDM is between 6-9 volts, and the voltage being reported by a low speed GMLAN serial data message is greater than 9 volts, then DTC B1424 00 sets.

Conditions for Running the DTC

* The ignition switch is in Accessory or Run.
* This diagnostic runs every 100 milliseconds.

Conditions for Setting the DTC

* Voltage at the TDM B+ circuit is between 6-9 volts.
* Reported battery voltage received via serial data is valid and is greater than 9 volts.
* The above conditions have been met for 2 seconds.

Action Taken When the DTC Sets

* The security indicator turns ON.
* The driver information center (DIC) displays the SERVICE THEFT DETERRENT SYSTEM message.

Conditions for Clearing the DTC

* A current DTC clears when the battery voltage at the TDM is greater than 9 volts, or if the voltage reported by serial data is less than 9 volts.
* A history DTC clears after 100 consecutive ignition cycles, if no failures are reported by this diagnostic.

Diagnostic Aids

* A low voltage DTC in multiple modules indicates a concern in the charging system.
* Verify that the ground terminal G201 is clean and tight.

Circuit/System Verification

1. Measure and record the voltage at the battery terminals. Verify that the battery voltage is greater than 11 volts.

^ If the battery voltage is less than the specified value, go to Charging System Test. Charging System Test

2. Verify that DTC B1424 is set as current.

^ If DTC B1424 is history, refer to Diagnostic Aids.

3. Refer to Circuit/System Testing.

Circuit/System Testing

1. Ignition OFF, disconnect the harness connector at the TDM.
2. Verify that there is less than 1.0 ohm between the ground circuit terminal 3 and the negative terminal of the battery.

^ If greater than the specified range, test the ground circuit for an open/high resistance.

3. Ignition ON. measure the voltage between the B+ circuit terminal 1 and the ground circuit terminal 3. Verify that the difference between the voltage at the TDM connector and the voltage at the battery terminals is less than 1 volt.

^ If greater than the specified value, test the B+ circuit for a short to ground or an open/high resistance.

4. If all circuits test normal, replace the TDM.

Repair Instructions

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