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 G301 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 (Acadia or Enclave) Charging System Test (OUTLOOK). 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. 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.

2. 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.

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

Repair Instructions

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