AutoCodes – Cadillac – B3655 Cadillac

B3655 Cadillac Code - Electrical Power Take Off Control Switch Circuit Low

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: B3655 Cadillac indicates Electrical Power Take Off Control Switch Circuit Low.
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 465

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 B3655 Cadillac 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 B3655 Cadillac - Electrical Power Take Off Control Switch Circuit Low - AutoCodes.com — B3655 Cadillac Code - Electrical Power Take Off Control Switch Circuit Low

What does this mean?

What are the Possible Causes of the DTC B3655 Cadillac?

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 B3655 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 B3655 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.

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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 B3655 Cadillac Code

1. What does the OBDII code B3655 mean on a Cadillac?

The B3655 code indicates an issue with the Electrical Power Take Off (PTO) Control Switch Circuit, specifically that the circuit is registering a low voltage condition.

2. What are the common symptoms of the B3655 code?

Symptoms may include inoperable PTO switch functions, a malfunctioning auxiliary electrical system, or the illumination of the check engine light or other warning indicators.

3. What causes the B3655 code to appear?

Common causes include a faulty PTO switch, damaged wiring or connectors in the circuit, or a malfunctioning control module.

4. How can I diagnose the B3655 code?

Start by inspecting the PTO switch and its wiring for visible damage. Use a multimeter to check for proper voltage and continuity in the circuit, and scan for additional trouble codes.

5. Can I drive my Cadillac with the B3655 code active?

It is generally safe to drive, but the PTO features may not function properly. Addressing the issue promptly is recommended to prevent further electrical problems.

6. How do I fix the B3655 code on my Cadillac?

Repairs may include replacing the PTO switch, repairing or replacing damaged wiring or connectors in the circuit, or reprogramming or replacing the control module if necessary.

7. How much does it cost to repair the B3655 code?

Repair costs can vary depending on the exact issue but typically range from $100 to $300 for parts and labor, depending on whether the switch, wiring, or module needs replacement.

8. Can a dead battery cause the B3655 code?

A weak or dead battery can potentially cause low voltage issues, which might trigger the B3655 code. Ensuring the battery is fully charged and in good condition is a good first step.

9. Does the B3655 code require a professional mechanic to fix?

While some issues like inspecting and replacing a switch or repairing wiring can be done by DIYers, diagnosing and fixing module-related problems may require a professional mechanic with advanced tools.

10. Will clearing the B3655 code with a scanner fix the problem?

Clearing the code may turn off the warning temporarily, but if the underlying issue is not resolved, the code will likely reappear. Proper diagnosis and repair are necessary.