AutoCodes – Generic – B0938

B0938 Code - Coolant Level Sensor Circuit Low

Quick Answer

The Powertrain Control Module (PCM) monitors the Coolant Level Sensor. Common causes include Low Coolant Level, Faulty Coolant Level Sensor, Coolant Level Sensor harness is open or shorted. Severity is High - diagnose this code as soon as possible. Driving is not recommended if the warning light is flashing, the engine runs poorly, or safety-related symptoms are present.

What it means: B0938 indicates Coolant Level Sensor Circuit Low.
Common causes: Common causes include Low Coolant Level, Faulty Coolant Level Sensor, Coolant Level Sensor harness is open or shorted.
Severity: High - diagnose this code as soon as possible.
Can I drive?: Driving is not recommended if the warning light is flashing, the engine runs poorly, or safety-related symptoms are present.

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Code Popularity 822

How popular is this code, among other codes? Low

Repair Importance Level

Urgent (Diagnose now) (3 / 3)

Repair Difficulty Level

Advanced (Pro) (3 / 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
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Code B0938 Description

The Powertrain Control Module (PCM) monitors the Coolant Level Sensor. The PCM sets the OBDII code when the Coolant Level Sensor is not to factory specifications.

OBDII Code B0938 - Coolant Level Sensor Circuit Low - AutoCodes.com — B0938 Code - Coolant Level Sensor Circuit Low

What does this mean?

What are the Possible Causes of the DTC B0938?

Low Coolant Level
Faulty Coolant Level Sensor
Coolant Level Sensor harness is open or shorted
Coolant Level Sensor circuit poor electrical connection

How to Fix the DTC B0938?

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 B0938 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 B0938 code?

Need more information on how to fix the B0938 code? Get Access to Factory Service Manuals

Need Help with the Code?

Get the B0938 code diagnosed by a professional: Find a repair shop in your area

Information for Specific Makes

B0938 Buick — Coolant Level Sensor Circuit Low
B0938 Cadillac — Coolant Level Sensor Circuit Low
B0938 Chevrolet — Coolant Level Sensor Circuit Low
B0938 GMC — Coolant Level Sensor Circuit Low
B0938 Pontiac — Coolant Level Sensor Circuit Low
B0938 Saturn — Coolant Level Sensor Circuit Low

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 B0938 Code

1. What does OBDII code B0938 mean?

Code B0938 indicates a problem with the coolant level sensor circuit, specifically that the circuit is reading a low voltage or signal.

2. What are the common symptoms of code B0938?

Symptoms may include a coolant level warning light on the dashboard, erratic coolant level readings, or overheating if the coolant level is genuinely low.

3. What causes code B0938 to appear?

Possible causes include a faulty coolant level sensor, damaged wiring or connectors, low coolant levels, or a malfunction in the vehicle's control module.

4. Can I keep driving with code B0938?

It depends; if the coolant level is adequate and the engine isnâ€™t overheating, limited driving may be possible. However, ignoring the issue could lead to engine damage if the coolant level is actually low.

5. How do I diagnose code B0938?

Start by visually inspecting the coolant level sensor, connectors, and wiring for damage or corrosion. Verify the coolant level and use a multimeter to test the sensor's voltage and resistance.

6. How is code B0938 fixed?

Repairs may include replacing the coolant level sensor, repairing damaged wiring or connectors, or refilling the coolant if it is low.

7. Can low coolant trigger code B0938?

Yes, if the coolant level is below the sensor's threshold, the code may be triggered. Always check and refill coolant as needed before further diagnosing.

8. Is code B0938 serious?

While not always critical, it can lead to more severe issues if the coolant level is genuinely low or the engine overheats. Prompt diagnosis and repair are recommended.

9. How much does it cost to fix code B0938?

Depending on the cause, repairs could range from $50 to $200, primarily if the coolant level sensor needs replacement or minor wiring repairs are required.

10. Can I clear code B0938 without fixing it?

The code can be cleared with an OBDII scanner, but it will likely return if the underlying issue isnâ€™t addressed.