Chevrolet Trax: DTC B0283: Rear defrost circuit

DIAGNOSTIC CODE INDEX

DTC B0283: REAR DEFROST CIRCUIT

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 B0283

Rear Defrost Circuit

For symptom byte information, refer to Symptom Byte List .

Diagnostic Fault Information

Circuit/System Description

The HVAC control module monitors the voltage level on the supply voltage circuit of the rear defog relay. The voltage level should be low while the rear defog relay is de-energized. The voltage will be near system voltage when the HVAC control module energizes the rear defog relay.

Conditions for Running the DTC

Ignition ON

Conditions for Setting the DTC

B0283 02

When the HVAC control module detects a short to ground in the relay control circuit for 1 second or greater

B0283 05

When the HVAC control module detects a short to battery or an open/high resistance in the relay control circuit or the relay ground circuit for 1 second or greater.

Action Taken When the DTC Sets

• If B0283 02 is current, the rear window defogger grid will be inoperative.
• If B0283 05 is current, the rear window defogger grid will operate continuously.

Conditions for Clearing the DTC

• The DTC will be current for as long as the fault is present.
• When the fault is no longer present, the DTC will be a history DTC.
• A history DTC will clear after 50 ignition cycles.

Reference Information

Schematic Reference

Defogger Schematics (Encore), Defogger Schematics (Trax)

Connector End View Reference

WIRING SYSTEMS AND POWER MANAGEMENT - COMPONENT CONNECTOR END VIEWS - INDEX - ENCORE WIRING SYSTEMS AND POWER MANAGEMENT - COMPONENT CONNECTOR END VIEWS - INDEX - TRAX

Description and Operation

Rear Window Defogger 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

1. Engine Running.
2. Verify the E18 Rear Defogger Grid turns ON and OFF pressing the rear window defogger switch.

• If the E18 Rear Defogger Grid does not turn ON or OFF

Refer to Circuit/System Testing

• If the E18 Rear Defogger Grid turns ON and OFF

3. All OK.

Circuit/System Testing

1. Ignition OFF and all vehicle systems OFF, disconnect the X2 harness connector at the X50A Fuse Block- Underhood. It may take up to 2 minutes for all vehicle systems to power down.
2. Test for less than 10 ohms between the ground circuit terminal C5 and ground.

If 10 ohms or greater

1. Ignition OFF.
2. Test for less than 2 ohms in the ground circuit end to end.

• If 2 ohms or greater, repair the open/high resistance in the circuit.
• If less than 2 ohms, repair the open/high resistance in the ground connection.
• If less than 10 ohms

3. Connect the X2 harness connector at the X50A Fuse Block-Underhood. Disconnect the X2 harness connector at the K33 HVAC Control Module, ignition ON.
4. Verify the E18 Rear Defogger Grid is not activated.

If the E18 Rear Defogger Grid is activated

1. Ignition OFF, disconnect the X2 harness connector at the X50A Fuse Block-Underhood.
2. Test for less than 1 V between the K33 HVAC Control Module control circuit terminal 19 and ground.

• If 1 V or greater, repair the short to voltage on the circuit.
• If less than 1 V, replace the X50A Fuse Block-Underhood.
• If the E18 Rear Defogger Grid is not activated

5. Connect a 3 A fused jumper wire between the control circuit terminal 19 and B+.
6. Verify the E18 Rear Defogger Grid activates.

If the E18 Rear Defogger Grid does not activate

1. Ignition OFF, remove the jumper wire, disconnect the X2 harness connector at the X50A Fuse Block-Underhood, ignition ON.
2. Test for infinite resistance between the K33 HVAC Control Module control circuit terminal 19 and ground.

• If less than Infinite resistance, repair the short to ground on the circuit.
• If infinite resistance

3. Test for less than 2 ohms in the control circuit end to end.

• If 2 ohms or greater, repair the open/high resistance in the circuit.
• If less than 2 ohms, replace the X50A Fuse Block-Underhood.
• If the E18 Rear Defogger Grid activates

7. Replace the K33 HVAC Control Module.

Repair Instructions

Perform the Diagnostic Repair Verification after completing the repair.

• Front Compartment Fuse Block Replacement
• Control Module References for HVAC control module replacement, programming and setup

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