HVAC - Manual

DTC B1023

Diagnostic Instructions

* Perform the Diagnostic System Check - Vehicle Diagnostic System Check - Vehicle prior to using this diagnostic procedure.

* Review Strategy Based Diagnosis Strategy Based Diagnosis for an overview of the diagnostic approach.

* Diagnostic Procedure Instructions Diagnostic Procedure Instructions provides an overview of each diagnostic category.

DTC Descriptors

DTC B1023 05

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Integral Switch Performance Short to Ground

DTC B1023 06

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Integral Switch Performance Short to Battery or Open

DTC B1023 61

-
Integral Switch Performance Signal Invalid

Circuit/System Description

This DTC may be set by an open or shorted 5 volt reference circuit to the auxiliary HVAC control module or an internal fault inside the HVAC control module for a stuck or shorted control button.

Conditions for Running the DTC

Battery voltage is between 9-16 volts and data link communications operate normally.

Conditions for Setting the DTC

The HVAC control module has internal fault inside the HVAC control module for a stuck or shorted control button or shorted 5 volt reference circuit.

Conditions for Clearing the DTC

* A current DTC clears when the malfunction is no longer present.

* A history DTC clears when the module ignition cycle counter reaches the reset threshold, without a repeat of the malfunction.

Reference Information

Schematic Reference

HVAC Schematics HVAC - Manual

Connector End View Reference

Component Connector End Views A/C Compressor Clutch

Description and Operation

* Air Temperature Description and Operation Air Temperature

* Air Delivery Description and Operation Air Delivery

Electrical Information Reference

* Circuit Testing Circuit Testing

* Connector Repairs Connector Repairs

* Testing for Intermittent Conditions and Poor Connections Testing for Intermittent Conditions and Poor Connections

* Wiring Repairs Wiring Repairs

Scan Tool Reference

Control Module References Programming and Relearning for scan tool information

Circuit/System Verification

1. Ignition ON, disconnect the harness connector at the auxiliary HVAC control module, test for 4.8-5.2 volts between the 5-volt reference circuit terminal 3 and ground.

• If less than the specified range, test the 5-volt reference circuit for a short to ground or an open/high resistance. If the circuit tests normal, replace the HVAC Control Module.

• If greater than the specified range, test the 5-volt reference circuit for a short to voltage. If the circuit tests normal, replace the HVAC Control Module.

2. Reprogram the HVAC control module that set DTC B1023. The module should successfully reprogram.

• If the module will not reprogram, replace the HVAC control module that set the DTC.

3. With a scan tool, clear the DTC.

4. Ignition OFF.

5. Wait 60 seconds, then recheck for DTCs. DTC B1023 should not set.

• If DTC B1023 sets, replace the module.

Repair Instructions

Perform the Diagnostic Repair Verification Verification Tests after completing the diagnostic procedure.

Control Module References Programming and Relearning for control module replacement, setup, and programming