AutoCodes – GMC – B0189 GMC

B0189 GMC Code - Sunload Sensor 2 Circuit Performance

Quick Answer

The sunload sensor is a 2-wire photo diode. Common causes include Faulty Sunload Sensor 2, Sunload Sensor 2 harness is open or shorted, Sunload Sensor 2 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: B0189 GMC indicates Sunload Sensor 2 Circuit Performance.
Common causes: Common causes include Faulty Sunload Sensor 2, Sunload Sensor 2 harness is open or shorted, Sunload Sensor 2 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.

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Code Popularity 884

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 10, 2021

Description
Possible Causes
How To Fix
Cost to Diagnose
FAQs
Comments
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Code B0189 GMC Description

The sunload sensor is a 2-wire photo diode. The vehicle uses left and right sunload sensors. The two sensors are integrated into the sunload sensor assembly along with the ambient light sensor. Low reference and signal circuits enable the sensor to operate. As the sunload increases, the sensor signal decreases. The sensor operates within an intensity range between completely dark and bright. The sensor signal varies between 0-5 volts. The Heating, Ventilation, and Air Conditioning (HVAC) Control Module converts the signal to a range between 0-255 counts. The sunload sensor provides the HVAC control module a measurement of the amount of light shining on the vehicle. Bright or high intensity, light causes the vehicles inside temperature to increase. The HVAC system compensates for the increased temperature by diverting additional cool air into the vehicle.

OBDII Code B0189 GMC - Sunload Sensor 2 Circuit Performance - AutoCodes.com — B0189 GMC Code - Sunload Sensor 2 Circuit Performance

What does this mean?

What are the Possible Causes of the DTC B0189 GMC?

Faulty Sunload Sensor 2
Sunload Sensor 2 harness is open or shorted
Sunload Sensor 2 circuit poor electrical connection
Faulty Heating, Ventilation, and Air Conditioning (HVAC) Control Module

How to Fix the DTC B0189 GMC?

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 B0189 GMC 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.

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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 B0189 GMC Code

What does OBDII code B0189 mean for GMC vehicles?

OBDII code B0189 indicates a problem with the Sunload Sensor 2 Circuit Performance, which measures the amount of sunlight entering the vehicle to adjust climate control settings.

What are the common symptoms associated with code B0189?

Common symptoms may include improper operation of the air conditioning system, inconsistent climate control settings, or the climate control system not responding correctly to sunlight changes.

What could cause the B0189 code to trigger?

Causes for the B0189 code can include a faulty sunload sensor, damaged wiring or connectors in the sensor circuit, or issues within the climate control module.

How can I diagnose the B0189 code effectively?

To diagnose B0189, check for any related trouble codes, inspect the sunload sensor and its wiring for damage, and verify the sensorâ€™s operation using a multimeter for proper voltage and resistance readings.

What repairs are commonly needed to fix code B0189?

Repairs may involve replacing a faulty sunload sensor, repairing damaged wiring or connectors, or reprogramming or replacing the climate control module if necessary.

Can I drive my GMC with the B0189 code active?

While you can drive your vehicle with the B0189 code active, you may experience issues with air conditioning and climate control, which could affect comfort, especially in extreme weather.

Is it necessary to clear the code after repairs are made?

Yes, after making repairs, it is important to clear the code using an OBDII scanner to reset the system and see if the problem reoccurs.

How can I prevent the B0189 code from triggering in the future?

To prevent the B0189 code, regularly inspect the sunload sensor and wiring for any signs of wear or damage, and ensure that your vehicle's electrical connections are clean and secure.

What should I do if the B0189 code keeps returning after repairs?

If the B0189 code keeps returning, further diagnosis may be needed to check for underlying issues, such as a malfunctioning climate control module or intermittent wiring problems.