AutoCodes – Generic – B3656

B3656 Code - Electrical Power Take Off Control Switch Circuit High

Quick Answer

The Auxiliary Power Outlet (APO) Switch controls the operation of the Hybrid Control Module (HCM) APO state manager. Common causes include Faulty Auxiliary Power Outlet (APO) Switch, Auxiliary Power Outlet (APO) Switch harness is open or shorted, Auxiliary Power Outlet (APO) Switch 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: B3656 indicates Electrical Power Take Off Control Switch Circuit High.
Common causes: Common causes include Faulty Auxiliary Power Outlet (APO) Switch, Auxiliary Power Outlet (APO) Switch harness is open or shorted, Auxiliary Power Outlet (APO) Switch 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 544

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 09, 2020

Description
Possible Causes
How To Fix
Cost to Diagnose
FAQs
Comments
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Code B3656 Description

The Auxiliary Power Outlet (APO) Switch controls the operation of the Hybrid Control Module (HCM) APO state manager. The APO state manager commands one of three states from the Starter Generator Control Module (SGCM) (APO Off, APO Normal, APO Continuous). The APO switch is a momentary button, its output signal an input to an HCM analogue channel. Five volts are supplied to the switch and the returned voltage is measured relative to HCM signal ground to determine the switch state. A resistor network in the switch circuitry ensures that shorted high and low states can be diagnosed successfully. There are 2 valid voltage ranges of the return signal, one representing switch open, the other representing switch closed. If the voltage is lower than a threshold, a short low is indicated. Similarly, if the voltage is greater than the short high threshold, a short 'high' is indicated. The Diagnostic Trouble Code (DTC) sets if voltage is lower than a calibrated value, a short low is indicated or if the voltage is greater than a calibrated value the short high is indicated.

OBDII Code B3656 - Electrical Power Take Off Control Switch Circuit High - AutoCodes.com — B3656 Code - Electrical Power Take Off Control Switch Circuit High

What does this mean?

What are the Possible Causes of the DTC B3656?

Faulty Auxiliary Power Outlet (APO) Switch
Auxiliary Power Outlet (APO) Switch harness is open or shorted
Auxiliary Power Outlet (APO) Switch circuit poor electrical connection
Faulty Hybrid Control Module (HCM)

How to Fix the DTC B3656?

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 B3656 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 B3656 code?

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Need Help with the Code?

Get the B3656 code diagnosed by a professional: Find a repair shop in your area

Information for Specific Makes

B3656 Buick — Electrical Power Take Off Control Switch Circuit High
B3656 Cadillac — Electrical Power Take Off Control Switch Circuit High
B3656 Chevrolet — Electrical Power Take Off Control Switch Circuit High
B3656 GMC — Electrical Power Take Off Control Switch Circuit High

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 B3656 Code

1. What are the common symptoms of OBDII code B3656?

The common symptoms of OBDII code B3656 (Electrical Power Take Off Control Switch Circuit High) include the power take-off (PTO) not engaging or disengaging properly, illuminated warning lights on the dashboard, and potential loss of functionality of the power take-off system.

2. What are the possible causes of OBDII code B3656?

Possible causes of OBDII code B3656 include a faulty power take-off control switch, damaged wiring or connectors in the PTO circuit, a short circuit in the PTO control circuit, or a malfunctioning PTO control module.

3. How can I diagnose OBDII code B3656?

Diagnosing OBDII code B3656 typically involves using a diagnostic scanner to retrieve the trouble codes, inspecting the power take-off control switch and related wiring for any visible damage, and testing the components of the PTO control circuit for proper functionality.

4. What are some repair tips for OBDII code B3656?

Repairing OBDII code B3656 may involve replacing a faulty power take-off control switch, repairing or replacing damaged wiring or connectors in the PTO circuit, addressing any short circuits in the PTO control circuit, or replacing a malfunctioning PTO control module.

5. Can OBDII code B3656 be fixed without professional help?

Depending on your level of automotive knowledge and experience, you may be able to address OBDII code B3656 on your own by following diagnostic procedures and repair tips provided in the vehicle's service manual. However, seeking professional help from a certified mechanic is recommended for accurate diagnosis and proper repair.

6. Is it safe to continue driving with OBDII code B3656 present?

It is generally not recommended to continue driving with OBDII code B3656 present, as it may lead to further damage to the power take-off system or other related components. It is advised to address the issue promptly to ensure the safe operation of your vehicle.

7. Can a simple reset of the vehicle's computer clear OBDII code B3656?

A simple reset of the vehicle's computer may temporarily clear OBDII code B3656, but if the underlying issue causing the code is not addressed, it is likely to reappear. It is important to diagnose and repair the root cause of the problem to prevent the code from returning.

8. How much does it typically cost to repair OBDII code B3656?

The cost of repairing OBDII code B3656 can vary depending on the specific cause of the issue, the extent of the repairs needed, and labor rates in your area. It is recommended to obtain estimates from multiple mechanics or repair shops to determine the cost of addressing the code.

9. Will OBDII code B3656 cause my vehicle to fail an emissions test?

OBDII code B3656 may cause your vehicle to fail an emissions test, as it indicates a malfunction in the power take-off control circuit. It is important to address the issue and clear the code before undergoing an emissions test to ensure compliance with regulations.

10. How can I prevent OBDII code B3656 from recurring in the future?

To prevent OBDII code B3656 from recurring in the future, it is important to properly maintain your vehicle's power take-off system, address any issues promptly, and follow recommended service intervals. Regular inspections and maintenance can help prevent the code from reappearing.