For 1990-2009 cars

### Diagnostic Instructions

• | Perform the Diagnostic System Check - Vehicle prior to using this diagnostic procedure.

• | 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 | Short to Ground | Open/High Resistance | Short to Voltage | Signal Performance
--- | --- | --- | --- | ---
B+ | B1424 00 | B1424 00 | -- | --
Ground | -- | B1424 00 | -- | --

### Circuit/System Description

The 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 serial data message is greater than 9 volts, then DTC B1424 00 sets.

### Conditions for Running the DTC

The ignition is ON.

### 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.

### Reference Information

#### Schematic Reference

Immobilizer Schematics

#### Connector End View Reference

Component Connector End Views

#### Description and Operation

• | Immobilizer Description and Operation

• | Charging System Description and Operation

#### Electrical Information Reference

• | Circuit Testing

• | Connector Repairs

• | Testing for Intermittent Conditions and Poor Connections

• | Wiring Repairs

#### Scan Tool Reference

Control Module References for scan tool information

### Circuit/System Testing

1. Engine running, accessories OFF, measure and record the battery voltage at the battery terminals. The voltage should be between 12.6 and 15.0 volts.

⇒ | If not within the specified range, refer to Charging System Test.

2. Ignition OFF, disconnect the harness connector at the TDM. Refer to Theft Deterrent Module Replacement.
3. Ignition OFF and scan tool disconnected, open and close the drivers door, and wait 1 minute. Test for less than 5 ohms between the ground circuit terminal 3 and ground.

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

4. Verify that a test lamp illuminates between the B+ circuit terminal 1 and ground.

⇒ | If the test lamp does not illuminate, test the B+ circuit for a short to ground or an open/high resistance.

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

### Repair Instructions

Perform the Diagnostic Repair Verification after completing the diagnostic procedure.

Control Module References for TDM replacement, set up, and programming.