AutoCodes – Generic – P16C4

P16C4 Code - Engine Mount Actuator Control Power Circuit Stuck Off

Quick Answer

The engine mount control system controls the engine mounts electronically. Common causes include Faulty Engine Mount Actuator, Engine Mount Actuator harness is open or shorted, Engine Mount Actuator 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: P16C4 indicates Engine Mount Actuator Control Power Circuit Stuck Off.
Common causes: Common causes include Faulty Engine Mount Actuator, Engine Mount Actuator harness is open or shorted, Engine Mount Actuator 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 7,584

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 Jan 10, 2020

Description
Possible Causes
How To Fix
Cost to Diagnose
FAQs
Comments
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Code P16C4 Description

The engine mount control system controls the engine mounts electronically. The system consists of the engine mount actuators, the engine mount control unit, and the Powertrain Control Module (PCM). The engine mount control unit uses the crankshaft and camshaft position sensor outputs (received from the PCM) to estimate engine vibration. The engine mount control unit then sends signals to the engine mount actuators to command the engine mounts to push and pull on the engine to counteract engine vibration. The engine mount control unit monitors the engine mount control unit voltage. If the ACM RLY OUT voltage is set value or less for a set time, the engine mount control unit detects a malfunction and stores a DTC.

OBDII Code P16C4 - Engine Mount Actuator Control Power Circuit Stuck Off - AutoCodes.com — P16C4 Code - Engine Mount Actuator Control Power Circuit Stuck Off

What does this mean?

What are the Possible Causes of the DTC P16C4?

Faulty Engine Mount Actuator
Engine Mount Actuator harness is open or shorted
Engine Mount Actuator circuit poor electrical connection
Faulty Engine Mount Control Unit

How to Fix the DTC P16C4?

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 P16C4 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 P16C4 code?

Need more information on how to fix the P16C4 code? Get Access to Factory Service Manuals

Need Help with the Code?

Get the P16C4 code diagnosed by a professional: Find a repair shop in your area

Information for Specific Makes

P16C4 Acura — Engine Mount Actuator Control Power Circuit Stuck Off
P16C4 Honda — Engine Mount Actuator Control Power Circuit Stuck Off

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 P16C4 Code

1. What does the OBDII code P16C4 mean?

P16C4 indicates an issue with the engine mount actuator control power circuit, specifically that it is stuck in the "off" position.

2. What are the symptoms of the P16C4 code?

Common symptoms include increased engine vibration, rough idling, and potentially unusual noises from the engine bay.

3. What causes the P16C4 code to appear?

Possible causes include a malfunctioning engine mount actuator, damaged or corroded wiring, a blown fuse, or a fault in the engine control module (ECM).

4. Can I drive with a P16C4 code?

While the car may be drivable, ignoring this code can lead to increased engine wear or discomfort due to excessive vibration.

5. How is the P16C4 code diagnosed?

A mechanic will inspect the engine mount actuator, check for wiring or connector damage, and test the actuator control circuit with a multimeter.

6. How do you fix the P16C4 code?

Repairs may include replacing the faulty engine mount actuator, repairing wiring or connectors, or updating/replacing the ECM if necessary.

7. How much does it cost to fix the P16C4 code?

Repair costs vary but typically range from $150 to $500 depending on whether the actuator, wiring, or ECM needs replacement.

8. Can a weak battery cause the P16C4 code?

Yes, insufficient power supply from a weak or dying battery can sometimes trigger this code.

9. What tools are needed to diagnose the P16C4 code?

Tools like an OBDII scanner, multimeter, and wiring diagrams for your specific vehicle are essential for diagnosis.

10. Does clearing the P16C4 code fix the problem?

Clearing the code may temporarily remove the warning, but the underlying issue must be addressed to prevent the code from returning.

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