AutoCodes – Generic – P1677

P1677 Code - Immobilizer Function Deactivated

Quick Answer

The Engine Control Module (ECM), the Powertrain Interface Module (PIM), and the Body Control Module (BCM) are integral part of the vehicle theft deterrent system. Common causes include Deterrent key not programmed to vehicle, Faulty Deterrent key, Faulty ignition switch. 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
P1677 indicates Immobilizer Function Deactivated.
Common causes
Common causes include Deterrent key not programmed to vehicle, Faulty Deterrent key, Faulty ignition switch.
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 8,771
How popular is this code, among other codes? Low
Table of contents Created and updated by William Orellana on Sep 08, 2019
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Code P1677 Description

The Engine Control Module (ECM), the Powertrain Interface Module (PIM), and the Body Control Module (BCM) are integral part of the vehicle theft deterrent system. The theft deterrent system authenticates the security code programmed into each of these modules to prevent unauthorized vehicle operation. This authentication process includes the following steps:
1.When the ignition is turned ON or the door is unlocked by remote key the BCM and the key exchange security data to verify the correct key is used.
2.Once the correct key has been confirmed and the ignition is turned ON, the PIM and BCM exchange data to confirm the correct BCM and PIM is being used.
3.Once the correct key, BCM, and PIM is confirmed, the PIM and ECM exchange data to allow the vehicle to start.
4.The data exchange processes conducted use various encrypted data exchanges between each of the devices.
OBDII Code P1677 - Immobilizer Function Deactivated - AutoCodes.com
P1677 Code - Immobilizer Function Deactivated

What are the Possible Causes of the DTC P1677?

  • Deterrent key not programmed to vehicle
  • Faulty Deterrent key
  • Faulty ignition switch
  • Poor electrical connection for Deterrent circuit components

How to Fix the DTC P1677?

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 P1677 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 P1677 code?

Need more information on how to fix the P1677 code? Get Access to Factory Service Manuals

Need Help with the Code?

Get the P1677 code diagnosed by a professional: Find a repair shop in your area

Information for Specific Makes

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 P1677 Code

1. What are the common symptoms of OBDII code P1677 (Immobilizer Function Deactivated)?

- The common symptoms include the engine not starting, the vehicle stalling immediately after starting, and the immobilizer light on the dashboard remaining illuminated.

2. What are the possible causes of OBDII code P1677?

- The possible causes of this code include issues with the immobilizer system, faulty key transponder, wiring issues in the immobilizer circuit, or a defective Engine Control Module (ECM).

3. How can I diagnose the cause of OBDII code P1677?

- Diagnosing this code typically involves checking the immobilizer system for faults, testing the key transponder, inspecting the wiring for any damage, and using a diagnostic scanner to retrieve further information from the ECM.

4. Can I still drive my vehicle with OBDII code P1677?

- It is not recommended to drive the vehicle with this code present, as the immobilizer function is an important security feature that may prevent the engine from starting properly.

5. How can I repair OBDII code P1677?

- Repairing this code often involves addressing the specific cause, such as reprogramming the key transponder, repairing any wiring issues, or replacing the faulty ECM. Consult a professional mechanic for accurate diagnosis and repair.

6. Are there any DIY tips for fixing OBDII code P1677?

- While some basic troubleshooting like checking the key fob battery and ensuring it is transmitting a signal can be done, resolving this code often requires specialized equipment and knowledge. It's best to seek assistance from a qualified technician.

7. Will disconnecting the battery reset OBDII code P1677?

- Disconnecting the battery may temporarily clear the code, but if the underlying issue is not addressed, the code is likely to return once the vehicle is driven and the ECM detects the problem again.

8. Is OBDII code P1677 a common issue in certain vehicle makes and models?

- This code can occur in various vehicle makes and models that are equipped with an immobilizer system. However, its frequency may vary depending on the manufacturer and model year.

9. Can a locksmith fix OBDII code P1677 related to the immobilizer system?

- Locksmiths may be able to assist with certain aspects of the immobilizer system, such as reprogramming keys or addressing key-related issues. However, complex ECM or wiring problems may require the expertise of an automotive technician.

10. How much does it typically cost to repair OBDII code P1677 at a repair shop?

- The cost of repairing this code can vary depending on the specific cause, parts needed for replacement, labor rates, and location. It is advisable to obtain quotes from different repair shops to compare prices.

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