B1424

DTC B1424

Diagnostic Instructions
^ Perform the [Diagnostic System Check - Vehicle Diagnostic Information] prior to using this diagnostic procedure. Diagnostic System Check - Vehicle Diagnostic Information
^ Review [Strategy Based Diagnosis] for an overview of the diagnostic approach. Strategy Based Diagnosis
^ [Diagnostic Procedure Instructions - Vehicle Diagnostic Information] provides an overview of each diagnostic category. Diagnostic Procedure Instructions - Vehicle Diagnostic Information

DTC Descriptor
DTC B1424 00 Device Voltage Low - Theft Deterrent Module

Diagnostic Fault Information






Circuit/System Description
The Passkey 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. Probe the ground circuit terminal 3 with a test lamp that is connected to B+. The test lamp should illuminate.
^ If the test lamp does not illuminate, then 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 - Vehicle Diagnostic Information] after completing the diagnostic procedure. Diagnostic Repair Verification - Vehicle Diagnostic Information