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 B1527: High Parasitic Load Detected

### Circuit/System Description

The body control module (BCM) monitors the state of charge (SOC) of the electrical system. If the BCM senses that the SOC at ignition On is 30 percent lower than what it was when the engine was running.

### Conditions for Running the DTC

The ignition must be in Accessory or Run mode for this code to set.

### Conditions for Setting the DTC

The SOC at ignition On is 30 percent lower than when the engine was running and battery drain is more than 2 amps.

### Action Taken When the DTC Sets

There is no battery telltale illuminated or DIC message displayed.

### Conditions for Clearing the DTC

• | The DTC will clear if the fault does not return after 50 consecutive ignition cycles.

• | The DTC will clear when run SOC is greater than or equal to 80 percent.

### Reference Information

#### Schematic Reference

Starting and Charging Schematics

#### Connector End View Reference

Component Connector End Views

#### 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 Verification

Ignition ON, compare the scan tool Prev. State of Charge and Start Up State of Charge parameters. The scan tool readings should not differ by greater than 30 percent.

⇒ | If the scan tool readings differ by greater than 30 percent, refer to Battery Electrical Drain/Parasitic Load Test

### Repair Instructions

Perform the Diagnostic Repair Verification after completing the diagnostic procedure.