AutoCodes – Generic – B370B

B370B Code - Rear Wiper Function Control Circuit Short to Ground

Quick Answer

The Body Control Module (BCM) controls the rear wiper motor based on an input from the rear wiper switch, which is part of the turn signal/multifunction switch. Common causes include Faulty Rear Window Wiper Motor, Rear Window Wiper Motor harness is open or shorted, Rear Window Wiper Motor circuit poor electrical connection. 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: B370B indicates Rear Wiper Function Control Circuit Short to Ground.
Common causes: Common causes include Faulty Rear Window Wiper Motor, Rear Window Wiper Motor harness is open or shorted, Rear Window Wiper Motor circuit poor electrical connection.
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 2,288

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 13, 2020

Description
Possible Causes
How To Fix
Cost to Diagnose
FAQs
Comments
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Code B370B Description

The Body Control Module (BCM) controls the rear wiper motor based on an input from the rear wiper switch, which is part of the turn signal/multifunction switch. The rear wiper switch uses a resistor ladder to determine low speed, intermittent, and rear washer operation. A constant B+ and ground are supplied to the rear wiper motor. When rear wiper operation is requested, the BCM sends serial data messages. When the rear wiper switch is placed in the low speed, intermittent, or rear washer position, the voltage is pulled down through a different resistor in the resistor ladder, reducing the voltage seen at the BCM. The BCM will respond by commanding the specific rear wiper function.
The BCM monitors the liftgate ajar signal circuit, and the BCM will disable the function of the rear wiper motor if the liftgate of liftglass is ajar or open.
The Diagnostic Trouble Code (DTC) sets when a short to voltage, short to ground or open or high resistance is detected in the rear wiper relay control circuit.

OBDII Code B370B - Rear Wiper Function Control Circuit Short to Ground - AutoCodes.com — B370B Code - Rear Wiper Function Control Circuit Short to Ground

What does this mean?

What are the Possible Causes of the DTC B370B?

Faulty Rear Window Wiper Motor
Rear Window Wiper Motor harness is open or shorted
Rear Window Wiper Motor circuit poor electrical connection
Faulty Body Control Module (BCM)

How to Fix the DTC B370B?

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 B370B 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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Need Help with the Code?

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Information for Specific Makes

B370B Cadillac — Rear Wiper Function Control Circuit Short to Ground
B370B Chevrolet — Rear Wiper Function Control Circuit Short to Ground
B370B Saturn — Rear Wiper Function Control Circuit Short to Ground

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 B370B Code

1. What are the common symptoms of OBDII code B370B (Rear Wiper Function Control Circuit Short to Ground)?

- Common symptoms include the rear wiper not working, erratic wiper movement, or the wiper getting stuck in one position.

2. What are the possible causes of the OBDII code B370B?

- Potential causes include damaged wiring or connectors in the rear wiper circuit, a faulty rear wiper motor, or a defective wiper switch.

3. How can I diagnose the issue related to OBDII code B370B?

- You can use a multimeter to test the continuity of the wiring, check for any visible damage, and inspect the rear wiper motor and switch for proper functioning.

4. What are some repair tips for fixing the Rear Wiper Function Control Circuit Short to Ground issue?

- Repair tips may include repairing or replacing damaged wiring, connectors, the rear wiper motor, or the wiper switch as needed to resolve the short to ground problem.

5. Can OBDII code B370B be safely ignored if the rear wiper is not essential?

- It is not recommended to ignore OBDII codes as they can indicate underlying issues that may affect other vehicle systems or lead to more significant problems in the future.

6. Is it safe to continue driving with the Rear Wiper Function Control Circuit Short to Ground issue?

- It is generally safe to drive with this issue, but it is advisable to address the problem promptly to ensure proper functioning of the rear wiper and prevent any potential electrical hazards.

7. How much does it typically cost to repair OBDII code B370B?

- The cost of repair can vary depending on the specific cause of the issue, but it may involve labor costs for diagnosis and repair, as well as the price of any necessary replacement parts.

8. Can a DIY enthusiast fix the Rear Wiper Function Control Circuit Short to Ground problem?

- Depending on your skill level and access to tools, you may be able to diagnose and repair this issue yourself, but it is recommended to have proper knowledge of automotive electrical systems.

9. Are there any preventive measures to avoid OBDII code B370B in the future?

- To prevent this issue, regular inspection of the rear wiper system, timely maintenance, and addressing any electrical problems promptly can help avoid the Rear Wiper Function Control Circuit Short to Ground code.

10. Will resetting the OBDII system clear the B370B code?

- Resetting the OBDII system may temporarily clear the code, but if the underlying issue causing the Rear Wiper Function Control Circuit Short to Ground is not addressed, the code is likely to return.