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 Descriptors

DTC B3795 02: Hazard Warning Switch Telltale Output Low Voltage
DTC B3795 05: Hazard Warning Switch Telltale Output High Voltage
DTC B3795 0f: Hazard Warning Switch Telltale Malfunction

### Diagnostic Fault Information

Circuit | Short to Ground | Open/High Resistance | Short to Voltage | Signal Performance
--- | --- | --- | --- | ---
Hazard Switch Signal | B3596 5a | B3596 5a | 1 | --
Hazard Switch Telltale Control | B3795 02 | B3795 02 | B3795 05 | B3795 0f
Hazard Switch Ground | -- | 1 | -- | --
1. Hazard Lamps Malfunction

### Circuit/System Description

The hazard flashers may be activated in any power mode. The hazard switch is located on the accessory control panel and is permanently grounded through ground G205. When the hazard switch is placed in the ON position, ground is applied through the hazard switch signal circuit to the instrument panel cluster (IPC). The IPC responds by sending a serial data message to the underhood electrical center (UEC) and the rear electrical center (REC) requesting the front and rear turn signal lamps be illuminated in an ON and OFF duty cycle. The UEC and REC respond by applying voltage to there respective turn signal control circuits illuminating the front and rear turn signal lamps ON and OFF. The IPC is also responsible for cycling both turn signal indicators ON and OFF. The IPC illuminates the hazard switch telltale by applying voltage to the hazard switch telltale signal circuit.

### Conditions for Running the DTC

• | Battery voltage must be between 9-16 volts.

• | Hazard lamps ON.

### Conditions for Setting the DTC

#### B3795 02

The DTC will set when the IPC detects a short to ground or an open/high resistance in the hazard switch telltale signal circuit.

#### B3795 05

The DTC will set when the IPC detects a short to voltage in the hazard switch telltale signal circuit.

#### B3795 0f

The DTC will set when the IPC detects an internal switch malfunction.

### Actions Taken When the DTC Sets

When DTC B3795 is present, the hazard switch telltale signal circuit will be disabled.

### Conditions for Clearing the DTC

• | The condition responsible for setting the DTC no longer exists.

• | A history DTC will clear once 100 consecutive malfunction-free ignition cycles have occurred.

### 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 Testing

1. Ignition OFF, disconnect the harness connector at the hazard switch.
2. Ignition OFF, verify a test lamp illuminates between B+ and the ground circuit terminal 2.

⇒ | If the test lamp does not illuminate, test the ground circuit for an open/high resistance.

3. Connect a test lamp between the control circuit terminal 15 and ground.
4. Command the Hazard Warning LED Test ON and OFF with a scan tool. The test lamp should turn ON and OFF when changing between the commanded states.

⇒ | If the test lamp is always OFF, test the control circuit for a short to ground or open/high resistance. If the circuit tests normal, replace the IPC.

⇒ | If the test lamp is always ON, test the control circuit for a short to voltage. If the circuit tests normal, replace the IPC.

5. If all circuits test normal, replace the hazard switch.

### Repair Instructions

Perform the Diagnostic Repair Verification after completing the diagnostic procedure.

• | Front Seat Heater Switch Replacement

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