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 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

• | This DTC passes 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.
3. Ignition OFF and scan tool disconnected, open and close the driver 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, setup, and programming.