For 1990-2009 cars

### Diagnostic Instructions

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

### DTC Descriptor

DTC B3596 00: Hazard Lamps Request Circuit Malfunction

### Diagnostic Fault Information

Circuit | Short to Ground | Open/High Resistance | Short to Voltage | Signal Performance
--- | --- | --- | --- | ---
Hazard Lamps Request | -- | -- | -- | B3596 00

### Circuit/System Description

The hazard flashers may be activated in any power mode. The hazard warning switch is permanently grounded. When the hazard warning switch is placed in the ON position, ground is applied through the hazard warning switch signal circuit to the body control module (BCM). The BCM supplies battery voltage to all turn signal lamps in an ON and OFF duty cycle.

### Conditions for Running the DTC

Hazard warning switch activated

### Conditions for Setting the DTC

Hazard warning switch stuck

### Action Taken When the DTC Sets

The hazard warning is inoperative.

### Conditions for Clearing the DTC

The condition for setting the DTC is no longer present.

### Reference Information

#### Schematic Reference

Exterior Lights Schematics

#### Connector End View Reference

Component Connector End Views

#### Description and Operation

Exterior Lighting Systems 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, observe the scan tool Hazard Lamps Switch parameter, that when the S26 Hazard Warning Switch is pressed and released the scan tool parameter toggle between Active and Inactive.

### Circuit/System Testing

1. Ignition OFF, disconnect the harness connector at the S26 Hazard Warning Switch.
2. Test for less than 5 Ω between the S26 Hazard Warning Switch harness connector ground circuit terminal 3 and ground.

⇒ | If greater than the specified value, test the ground circuit for an open/high resistance. If the circuit tests normal, replace the S26 Hazard Warning Switch.

3. Connect the harness connector at the S26 Hazard Warning Switch.
4. Disconnect the X2 harness connector at the K9 Body Control Module (BCM).
5. Ignition ON, test for less than 0.3 V at the K9 Body Control Module (BCM) X2 harness connector signal circuit terminal 26 and ground.

⇒ | If greater than the specified value, test the signal circuit for a short to voltage. If the circuit tests normal, replace the S26 Hazard Warning Switch.

6. Ignition OFF, test for infinite resistance between the K9 Body Control Module (BCM) X2 harness connector signal circuit terminal 26 and ground.

⇒ | If less than the specified value, test the signal circuit for a short to ground. If the circuit tests normal, replace the S26 Hazard Warning Switch.

7. Hazard Switch ON, test for 90-110 Ω between the K9 Body Control Module (BCM) X2 harness connector signal circuit terminal 26 and ground.

⇒ | If not within the specified range, test the signal circuit for an open/high resistance. If the circuit tests normal, replace the S26 Hazard Warning Switch.

8. If all circuits test normal, replace the K9 Body Control Module (BCM).

### Component Testing

#### Static Test

1. Ignition OFF, disconnect the harness connector at the S26 Hazard Warning Switch.
2. Test for infinite resistance between the S26 Hazard Warning Switch terminal 1 and terminal 3.

⇒ | If less than the specified value, replace the S26 Hazard Warning Switch.

3. Hazard Switch ON, test for 90-110 Ω between the S26 Hazard Warning Switch terminal 1 and terminal 3.

⇒ | If not within the specified range, replace the S26 Hazard Warning Switch.

### Repair Instructions

Perform the Diagnostic Repair Verification after completing the diagnostic procedure.

• | Hazard Warning Switch Replacement

• | Control Module References for BCM replacement, setup and programming