AutoCodes – BMW – P16C5 BMW

P16C5 BMW Code - Main Relay Switching Delay

Quick Answer

The Engine Control Module (ECM) monitors the Main Relay. Common causes include Faulty Main Relay, Main Relay harness is open or shorted, Main Relay 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: P16C5 BMW indicates Main Relay Switching Delay.
Common causes: Common causes include Faulty Main Relay, Main Relay harness is open or shorted, Main Relay 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 4,980

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 P16C5 BMW Description

The Engine Control Module (ECM) monitors the Main Relay. The ECM sets the OBDII code when the Main Relay is not to factory specifications.

OBDII Code P16C5 BMW - Main Relay Switching Delay - AutoCodes.com — P16C5 BMW Code - Main Relay Switching Delay

What does this mean?

What are the Possible Causes of the DTC P16C5 BMW?

Faulty Main Relay
Main Relay harness is open or shorted
Main Relay circuit poor electrical connection

How to Fix the DTC P16C5 BMW?

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 P16C5 BMW 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 P16C5 BMW code?

Need more information on how to fix the P16C5 BMW code? Get Access to Factory Service Manuals

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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 P16C5 BMW Code

1. What are the common symptoms of OBDII code P16C5 Main Relay Switching Delay in a BMW?

- Common symptoms include intermittent starting issues, engine stalling, and the vehicle not responding when turning the key.

2. What could cause the Main Relay Switching Delay code P16C5 in a BMW?

- Possible causes include a faulty main relay, wiring issues, poor electrical connections, or a malfunctioning engine control module (ECM).

3. How can I diagnose the cause of OBDII code P16C5 in my BMW?

- To diagnose the issue, you can perform a visual inspection of the main relay and related wiring, conduct a voltage test on the relay, and use a scan tool to check for any stored fault codes.

4. Can a DIY enthusiast repair OBDII code P16C5 Main Relay Switching Delay in a BMW?

- DIY repairs may be possible if you have the necessary tools and experience working on automotive electrical systems. However, it's recommended to seek professional help for accurate diagnosis and repair.

5. What are the potential risks of driving with OBDII code P16C5 active in a BMW?

- Driving with this code present can lead to unexpected engine shutdowns or starting issues, potentially leaving you stranded on the road. It's best to address the issue promptly.

6. Is resetting the OBDII code P16C5 Main Relay Switching Delay in a BMW sufficient to fix the problem?

- Simply resetting the code may temporarily clear the warning light, but it won't address the underlying issue causing the delay in the main relay switching.

7. How much does it typically cost to repair OBDII code P16C5 Main Relay Switching Delay in a BMW at a dealership or repair shop?

- Repair costs can vary based on the specific cause of the issue, but expect to pay for diagnostic time, parts, and labor. Costs may range from a few hundred to over a thousand dollars.

8. Can a faulty main relay cause other problems besides triggering OBDII code P16C5 in a BMW?

- Yes, a faulty main relay can cause various electrical issues in the vehicle, including starting problems, stalling, or even complete engine failure in some cases.

9. Are there any preventive measures to avoid encountering OBDII code P16C5 Main Relay Switching Delay in a BMW?

- Regularly inspecting and maintaining the electrical components in your BMW, such as the main relay and wiring, can help prevent issues that may trigger this OBDII code.

10. How long does it typically take to repair OBDII code P16C5 Main Relay Switching Delay in a BMW?

- The repair time can vary depending on the exact cause of the issue, but it may take a few hours to a full day for diagnosis, parts replacement, and testing.