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P1612 Infiniti Code - Chain of ECM-IMMU

Quick Answer

The P1612 code in Infiniti vehicles refers to a communication error between the Engine Control Module (ECM) and the Immobilizer Control Module (IMMU). Common causes include Faulty wiring or connectors between the ECM and IMMU, Malfunctioning ECM or IMMU, Low battery voltage. 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
P1612 Infiniti indicates Chain of ECM-IMMU.
Common causes
Common causes include Faulty wiring or connectors between the ECM and IMMU, Malfunctioning ECM or IMMU, Low battery voltage.
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.
What is this?
Table of contents Created and updated by William Orellana on Sep 10, 2024
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Code P1612 Infiniti Description

The P1612 code in Infiniti vehicles refers to a communication error between the Engine Control Module (ECM) and the Immobilizer Control Module (IMMU). The ECM controls the engine's performance, while the IMMU is responsible for the vehicle's security system, including the ignition key recognition. When there is a breakdown in communication between these two vital components, it can lead to various issues affecting the vehicle's performance and security.

OBDII Code P1612 Infiniti - Chain of ECM-IMMU
P1612 Infiniti Code - Chain of ECM-IMMU

Common Causes of P1612 Infiniti

  1. Faulty wiring or connectors between the ECM and IMMU
  2. Malfunctioning ECM or IMMU
  3. Low battery voltage
  4. Software issues in the ECM or IMMU
  5. Water damage or corrosion in the components

Symptoms of P1612 Infiniti

  1. Engine not starting
  2. Stalling or rough idling
  3. Reduced fuel efficiency
  4. Vehicle entering "limp mode"
  5. Security system issues, such as the vehicle not recognizing the key

How to Fix P1612 Infiniti

  1. Perform a thorough inspection of the wiring and connectors between the ECM and IMMU to check for any damage or corrosion.
  2. Test the battery voltage to ensure it is within the proper range for the ECM and IMMU to function correctly.
  3. Check for any software updates or reprogramming needed for the ECM or IMMU.
  4. Replace any faulty ECM or IMMU components if necessary.
  5. Clear the code from the vehicle's computer system and test to ensure the issue has been resolved.

Cost to Fix P1612 Infiniti

The typical repair costs for addressing the P1612 code in an Infiniti vehicle can range from $200 to $500, depending on the specific issue causing the communication error and the cost of replacement parts. This estimate includes parts and labor, but additional costs may apply if further diagnostics or repairs are needed. It's essential to consult with a qualified mechanic or dealership to get an accurate quote based on the vehicle's make and model, as well as the extent of the problem. Labor rates can vary, so it's advisable to inquire about pricing before proceeding with the repairs.

What does this mean?

Tech Notes for P1612 Infiniti

This code is usually triggered when a not registered or damaged key is used to start the engine. When the starting operation is carried out five or more times consecutively with the same unregistered key, the system will lock.



If the problem occurs try disconnecting the car battery for about 30 minutes and then try starting the engine with a known registered key. If the problem persists you have to have the dealer erase the code and reprogram the keys again.

When is the Code Detected?

Communication impossible between ECM and IMMU (In rare cases, “CHAIN OF ECM-IMMU” might be stored during key registration procedure, even if the system is not malfunctioning.)

Need more information about the P1612 Infiniti code?

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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 P1612 Infiniti Code

1. What is OBDII code P1612 in Infiniti vehicles?

Code P1612 indicates a communication error between the engine control module (ECM) and the immobilizer (IMMU) system in Infiniti vehicles.

2. What are the common symptoms of OBDII code P1612 in an Infiniti?

Common symptoms of code P1612 include the vehicle not starting, the engine cranking but not firing up, and the immobilizer warning light staying illuminated on the dashboard.

3. What are some possible causes of OBDII code P1612 in an Infiniti?

Potential causes of code P1612 include a faulty immobilizer control unit, a malfunctioning ECM, issues with wiring or connections between the ECM and IMMU, or a drained car battery.

4. How can I diagnose OBDII code P1612 in my Infiniti?

Diagnosing code P1612 typically involves using a professional diagnostic scanner to retrieve the fault codes, checking the wiring and connections between the ECM and IMMU, and performing a thorough inspection of the immobilizer system.

5. Can I drive my Infiniti with OBDII code P1612?

It is not recommended to drive your Infiniti with code P1612 present, as it can lead to starting issues or potential immobilization of the vehicle while driving.

6. How can I repair OBDII code P1612 in my Infiniti?

Repairing code P1612 may involve replacing the immobilizer control unit, reprogramming the immobilizer system, checking and repairing any wiring issues, or resetting the ECM and IMMU communication.

7. Can a DIY enthusiast fix OBDII code P1612 in an Infiniti?

While some simple checks like verifying connections can be done by a DIY enthusiast, diagnosing and repairing code P1612 often requires specialized tools and knowledge, so it is recommended to seek professional help.

8. How much does it cost to fix OBDII code P1612 in an Infiniti?

The cost of fixing code P1612 can vary depending on the exact cause of the issue. Repairs may range from a simple wiring fix to replacing the immobilizer control unit, with costs potentially ranging from a few hundred to over a thousand dollars.

9. Will resetting the ECM clear OBDII code P1612 in my Infiniti?

Resetting the ECM alone may not necessarily clear code P1612 if the underlying issue between the ECM and IMMU persists. It's important to diagnose the problem accurately before attempting any resets.

10. How can I prevent OBDII code P1612 from occurring in my Infiniti?

To prevent code P1612, it's essential to maintain your vehicle's battery health, ensure proper connections between the ECM and IMMU, and address any immobilizer system warning signs promptly to prevent potential communication errors.

Discuss the causes and fixes for P1612 Infiniti OBDII Code

Submit a New Comment

  • Hi...

    I have a nissan sentra 1.8L - 2002, the machine does not want to live, and there is a code when scanned P1612.

    how to make the engine back to life, what should I do.

    oh..ya ... I've tried to unplug the battery but still can not also.

    please help me

    Reply to Comment

  • You have to reprogram the the key to your vehicle. If you can't reprogram the keys, the you probably have to replace the IMMU, which is the part around the ignition switch that reads the key.

    Reply to Comment