ezOBD2 - Free OBD2 Code Lookup and Check Engine Light Diagnostic Tool

Diagnose Your Check Engine Light

Enter OBDII code below:

Code P1720

Symptoms

• Check Engine Light illuminated

• Intermittent or complete loss of certain vehicle functions

• Erratic vehicle behavior

Common Causes

• Faulty control module

• Damaged or corroded wiring

• Loose or poor connections in the CAN bus network

Glossary

CAN: Controller Area Network, a vehicle bus standard designed to allow microcontrollers and devices to communicate with each other.

ECM: Engine Control Module, a type of electronic control unit that manages engine performance.

Related Codes

• P1721

• P1722

Official description

CAN Timeout Control Module

Laymans terms

This code means that a part of the car's computer system isn't talking to another part like it should. Imagine if two friends stopped talking to each other and couldn't share important information.

Explanation

The P1720 code indicates a communication issue between modules on the Controller Area Network (CAN) bus, specifically a timeout error.

Technical description

The P1720 code is triggered when the Engine Control Module (ECM) or another control module on the CAN bus does not receive a signal from a specific module within the expected time frame. This can occur due to a fault in the wiring, a malfunctioning module, or a network issue.

Diagnosis steps

• Use an OBD-II scanner to confirm the code and check for other related codes.

• Inspect the CAN bus wiring and connectors for damage or corrosion.

• Test the suspected control module for proper operation.

Repair procedures

• Repair or replace damaged wiring or connectors.

• Replace the faulty control module if necessary.

• Clear the code and test drive the vehicle to ensure the issue is resolved.

Tools required

• OBD-II scanner

• Multimeter

• Wiring repair kit

Estimated repair cost

$100 - $1000, depending on the issue

Difficulty level

Moderate

Commonly affected vehicles

• Nissan Altima

• Infiniti G35

• Subaru Outback

Preventive measures

• Regularly inspect and maintain vehicle wiring.

• Ensure all software updates are applied to control modules.

• Avoid exposure to moisture and corrosive elements.

Error code type

Communication Issue

User experience recommendations

• Do not ignore the Check Engine Light.

• Consult a professional mechanic for diagnosis and repair.

Warranty information

Check with the vehicle manufacturer for warranty coverage on control modules.

Historical data

This code has been more prevalent in vehicles with complex electronic systems and CAN bus networks.

Urgency level

Moderate – While the vehicle may still operate, certain functions may be impaired.

Legal and safety notice

Driving with a malfunctioning control module may lead to unsafe vehicle operation.

Testing conditions

• Vehicle parked with ignition on.

• Engine running at idle.

Component location

The control module is typically located in the engine bay or under the dashboard, depending on the vehicle model.

FAQs

Q: Can I drive with a P1720 code?
A: It's not recommended as it may affect vehicle performance and safety.

Q: How do I reset the P1720 code?
A: After repairs, use an OBD-II scanner to clear the code from the vehicle's memory.

Last updated: Jan 16, 2026 • Source: internal database
🌙