AutoCodes – Cadillac – B0428 Cadillac

B0428 Cadillac Code - Auxiliary Air Temperature Actuator

Quick Answer

The Auxiliary Heating, Ventilation, and Air Conditioning (HVAC) actuators are a 5-wire bi-directional electric motor that incorporates a feedback potentiometer. Common causes include Faulty Auxiliary Air Temperature Actuator, Auxiliary Air Temperature Actuator harness is open or shorted, Auxiliary Air Temperature Actuator circuit poor electrical connection. Severity is Low - monitor the vehicle and repair when practical. The vehicle can usually be driven if no severe symptoms are present, but symptoms should be checked before extended driving.

What it means: B0428 Cadillac indicates Auxiliary Air Temperature Actuator.
Common causes: Common causes include Faulty Auxiliary Air Temperature Actuator, Auxiliary Air Temperature Actuator harness is open or shorted, Auxiliary Air Temperature Actuator circuit poor electrical connection.
Severity: Low - monitor the vehicle and repair when practical.
Can I drive?: The vehicle can usually be driven if no severe symptoms are present, but symptoms should be checked before extended driving.

Save to My Repairs My Repairs

AI answers can be wrong. Verify repairs with testing. Open full chat

Code Popularity 1,923

How popular is this code, among other codes? Low

Repair Importance Level

Low (Monitor) (1 / 3)

Repair Difficulty Level

Intermediate (2 / 3)

What is this?

Table of contents Created and updated by William Orellana on Mar 11, 2021

Description
Possible Causes
How To Fix
Cost to Diagnose
FAQs
Comments
Add Comment

💬 Need more help? Ask Coddy for instant answers — it's free!

Code B0428 Cadillac Description

The Auxiliary Heating, Ventilation, and Air Conditioning (HVAC) actuators are a 5-wire bi-directional electric motor that incorporates a feedback potentiometer. Low reference, 5-volt reference, position signal, and 2 control circuits enable the actuator to operate. The control circuits use either a 0 or 12 volt value to coordinate the actuator movement. When the actuator is at rest, both control circuits have a value of 0 volts. In order to move the actuator, the HVAC control module grounds one of the control circuits while providing the other with 12 volts. The auxiliary HVAC control module reverses the polarity of the control circuits to move the actuator in the opposite direction. When the actuator shaft rotates, the potentiometers adjustable contact changes the door position signal between 0-5 volts. This signal then is converted into a count value where as 1 volt will equal 51 counts.
The auxiliary HVAC control module calibrates the travel range of the HVAC door actuators when it is initially powered by the battery positive voltage circuit. During calibration, the module commands the actuators in each direction until door travel is stopped. The module stores the minimum door positions and the maximum door positions of each actuator into memory. The total travel range is calculated by subtracting the minimum door position from the maximum door position.

OBDII Code B0428 Cadillac - Auxiliary Air Temperature Actuator - AutoCodes.com — B0428 Cadillac Code - Auxiliary Air Temperature Actuator

What does this mean?

What are the Possible Causes of the DTC B0428 Cadillac?

Faulty Auxiliary Air Temperature Actuator
Auxiliary Air Temperature Actuator harness is open or shorted
Auxiliary Air Temperature Actuator circuit poor electrical connection
Faulty Auxiliary Heating, Ventilation, and Air Conditioning (HVAC) Control Module

How to Fix the DTC B0428 Cadillac?

Review the 'Possible Causes' above and visually examine the corresponding wiring harness and connectors. Check for damaged components and inspect connector pins for signs of being broken, bent, pushed out, or corroded.

What is the Cost to Diagnose the Code?

Labor: 1.0

To diagnose the B0428 Cadillac code, it typically requires 1.0 hour of labor. Rates vary by location, vehicle, and shop. Many shops charge between $80–$150 per hour; dealerships and metro areas may be higher, independents may be lower.

Need more information about the B0428 Cadillac code?

Need more information on how to fix the B0428 Cadillac code? Get Access to Factory Service Manuals

Need Help with the Code?

Get the B0428 Cadillac code diagnosed by a professional: Find a repair shop in your area

About the author: William Orellana is a Master Mechanic and Mechanical Engineer with over 30 years of experience diagnosing and repairing vehicles. Learn more about his background.

Frequently Asked Questions about B0428 Cadillac Code

1. What does OBDII code B0428 for a Cadillac indicate?

Code B0428 indicates a problem with the Auxiliary Air Temperature Actuator in a Cadillac vehicle.

2. What are the common symptoms of a faulty Auxiliary Air Temperature Actuator?

Common symptoms include inconsistent cabin temperature, poor air conditioning performance, and unusual noises coming from the HVAC system in the Cadillac.

3. What are the potential causes of OBDII code B0428 in a Cadillac?

Possible causes include a defective Auxiliary Air Temperature Actuator, wiring issues, electrical connector problems, or a faulty HVAC control module in the Cadillac.

4. How can I diagnose a B0428 code related to the Auxiliary Air Temperature Actuator in my Cadillac?

Diagnosing the issue may involve using a scan tool to retrieve the code, checking the actuator for proper operation, inspecting the wiring and connectors for damage, and testing the HVAC system components in the Cadillac.

5. Is it safe to continue driving my Cadillac with an unresolved B0428 code?

It is generally not recommended to drive the vehicle with a B0428 code, as it can affect the performance of the HVAC system and lead to discomfort while driving. It's best to address the issue promptly.

6. Can I repair a faulty Auxiliary Air Temperature Actuator in my Cadillac myself?

Depending on your automotive skills and access to tools, you may be able to replace the Auxiliary Air Temperature Actuator yourself. However, professional diagnosis and repair by a certified mechanic are recommended for accurate and reliable service.

7. Are there any preventive maintenance tips to avoid OBDII code B0428 in a Cadillac?

Regularly servicing the HVAC system, checking for any unusual noises or temperature inconsistencies, and addressing any issues promptly can help prevent the occurrence of code B0428 in a Cadillac.

8. How much does it typically cost to repair a faulty Auxiliary Air Temperature Actuator in a Cadillac?

The cost of repair can vary depending on the specific issue, labor rates, and whether genuine Cadillac parts are used. It's advisable to obtain quotes from reputable repair shops for accurate pricing.

9. Can a faulty Auxiliary Air Temperature Actuator impact fuel efficiency in a Cadillac?

While the actuator's main function is related to the HVAC system, a malfunctioning component can indirectly affect the vehicle's overall performance, including fuel efficiency, due to increased strain on the system.

10. How long does it usually take to replace the Auxiliary Air Temperature Actuator in a Cadillac?

The time required for replacement can vary based on the model year of the Cadillac, accessibility of the actuator, and the expertise of the technician. In general, it may take a few hours to complete the replacement procedure.