[SOLVED] P1766 Code: Can Communication Bus Off – Troubleshooting And Fix

The automobile fault code P1766 indicates a problem with the Controller Area Network (CAN) Bus. This can result in the Engine Light being ON or the Service Engine Soon Warning Light appearing.

The possible causes include an open or short circuit in the CAN comm line, a faulty Transfer Case Control Unit (TCCU), ECU, or Anti-Lock Brake System (ABS) Module.

To fix this issue, visually inspect the wiring harness and connectors for any damage. Check for broken, bent, pushed out, or corroded pins in the connectors.

The repair time for this fault code is estimated to be 1.0.

It is important to address this issue promptly to prevent further damage to the vehicle.

Repair Importance Level10.0 (Out of 10)
Estimated Repair TimeApproximately 1.0 hour
Repair Difficulty Level10.0 (Out of 10)

When the engine light is on or the service engine soon warning light is illuminated, it could be a sign of the p1766 fault code.

  • The symptoms of the automobile fault code P1766 include the Engine Light being ON or the Service Engine Soon Warning Light being illuminated.

INNOVA 5210
Get an OBD Scanner for accurate, Your car-specific Error Diagnosis
  • Pinpoints your car-specific issues, giving accurate diagnostics for your exact make and model.
  • Works anywhere, even with limited connectivity, making it highly versatile.
  • Provides detailed insights into real-time performance for your exact make and model, beyond generic online explanations.
  • Tracks past issues of your vehicle, helping you spot recurring problems and monitor long-term performance, which online resources can’t offer.
  • Detects potential issues early, helping avoid costly repairs instead of just addressing current problems.
  • Regular checks support efficiency and emissions standards, potentially increasing resale value—hard to gauge with online info alone.
Buying through our links may earn us commission.

The automobile fault code p1766 can be caused by issues with the Controller Area Network (CAN) Bus, CAN comm line circuit, TCCU, ECU, or ABS Module.

  • The fault code P1766 can be caused by various factors, including issues with the Controller Area Network (CAN) Bus, an open or short circuit in the CAN communication line, a faulty Transfer Case Control Unit (TCCU), a faulty Engine Control Unit (ECU), and a faulty Anti-Lock Brake System (ABS) Module.

To fix the p1766 fault code, start by visually inspecting the wiring harness, connectors, and components for any damage or corrosion.

  • To fix the automobile fault code P1766, you need to follow these steps: 1.
  • Check the possible causes mentioned above.
  • 2.
  • Visually inspect the wiring harness and connectors related to the fault code.
  • 3.
  • Look for any damaged components.
  • 4.
  • Check for broken, bent, pushed out, or corroded pins in the connectors.
  • The estimated repair time for this fix is 1.0 hour.

The factors influencing the cost of diagnosing and fixing the automobile fault code p1766 are the estimated repair time of 1.0 hour and the typical hourly rate charged by auto repair shops, which ranges between $75 and $150.

The P1766 fault code refers to a communication issue between the Engine Control Module (ECM) and the Transfer Case Control Unit (TCCU) in a vehicle.

This fault code is triggered when the CAN signal from the ECM cannot be received for more than 1 second or when there is an internal error in the ECM.

The CAN communication system is a parallel circuit that allows different units in the vehicle to exchange information quickly and efficiently. The CAN-High and CAN-Low lines are twisted together to prevent noise interference.

However, if the communication between the ECM and TCCU is disrupted, the TCCU will prevent the ITM control. In simpler terms, the P1766 fault code indicates a problem with the communication bus between the ECM and TCCU. This can be caused by a loss of signal or an internal error in the ECM.

When this fault code is present, it is important to diagnose and fix the communication issue to ensure proper functioning of the vehicle’s systems.

What are the possible causes for the automobile fault code p1766 and how can I visually inspect them?

If you’re seeing the engine light on or the service engine soon warning light, the fault code P1766 could be the culprit. This code is often caused by issues with the Controller Area Network (CAN) Bus, a circuit that may be open or shorted. Other potential causes include a faulty Transfer Case Control Unit (TCCU), ECU, or Anti-Lock Brake System (ABS) Module. To visually inspect these possible causes, check the related wiring harness and connectors for any damage. Look out for broken, bent, pushed out, or corroded pins on the connectors.

How can a faulty Transfer Case Control Unit (TCCU) or Anti-Lock Brake System (ABS) Module contribute to the engine light being ON and how can I check for these faults?

If you notice that your engine light is ON or you see the Service Engine Soon Warning Light, it could be due to a faulty Transfer Case Control Unit (TCCU) or Anti-Lock Brake System (ABS) Module. These issues can be caused by problems with the Controller Area Network (CAN) Bus, CAN comm line circuit open/short, or a faulty ECU. To check for these faults, visually inspect the wiring harness and connectors, looking for any damage or broken, bent, pushed out, or corroded pins. This will help you identify and fix the problem.

What steps should I take to fix the p1766 fault code and ensure that the wiring harness and connectors are in good condition?

To fix the p1766 fault code and ensure the wiring harness and connectors are in good condition, start by checking the listed possible causes. Then, visually inspect the wiring harness and connectors for any damage. Look for broken, bent, pushed out, or corroded pins on the connectors. This will help identify any issues and allow for proper repairs to be made.

p1766 error fault code explained

If your engine light is on and you’re seeing the p1766 fault code, it could be due to a problem with the Controller Area Network (CAN) Bus, a circuit open or short, a faulty Transfer Case Control Unit (TCCU), ECU, or Anti-Lock Brake System (ABS) Module.

To fix it, visually inspect the wiring harness and connectors, check for damaged components, and look for any broken, bent, pushed out, or corroded connector pins.

Scroll to Top