how to troubleshoot the CAN bus communication error on my Toyota Highlander Third Generation (2014-2...

Toyota Highlander Third Generation (2014-2019)

Error Codes

2-4 hours

Time

medium

Difficulty

high

Severity

3 min read

578 words

⚠️ Safety Warning

This issue requires immediate attention. If you are not experienced with automotive repairs, consult a professional mechanic. Working on critical systems can be dangerous.

Problem Statement

Learn how to troubleshoot CAN bus communication errors in Toyota Highlander (2014-2019). Step-by-step guide with symptoms, diagnostic steps, and solutions.

Affected Component

Electrical

Estimated Time

2-4 hours

⚠️ Safety Warnings

Important safety information - read before proceeding

•Disconnect the battery before working on electrical systems to prevent shocks or shorts.
•Ensure the vehicle is in a well-ventilated area when working with electrical components.

Symptoms

•Check engine light illuminated
•Inoperative dashboard gauges or warning lights
•Malfunctioning electronic features (e.g., power windows, door locks)
•Error messages displayed on the infotainment system
•Intermittent loss of communication with OBD-II scanner

Diagnostic Steps

1
Verify the presence of any active or stored trouble codes using an OBD-II scanner.
2
Inspect the vehicle’s fuses related to the CAN bus network for any blown fuses.
3
Examine the wiring harness and connectors between the modules for damage or corrosion.
4
Measure the voltage on the CAN high and CAN low wires using a multimeter.
5
Check the individual modules (ECM, BCM, etc.) for proper operation and connectivity.
6
Use a CAN bus analyzer if available to monitor data traffic and identify communication issues.

Solution

💡 Expert Tip

For complex repairs like this, consider taking photos at each step. This helps if you need to reverse a step or consult with a mechanic. Also, keep all removed parts organized - you may need to reference them during reassembly.

Verification

After completing the repair, verify that the issue has been resolved:

✓Test the affected component to ensure it functions correctly
✓Check for any error codes or warning lights
✓Monitor the vehicle for a few days to ensure the issue does not recur

Prevention Tips

To prevent this issue from occurring again:

•Follow the manufacturer's recommended maintenance schedule
•Address warning signs early before they develop into major issues
•Use quality parts and fluids recommended for your vehicle
•Keep detailed records of all repairs and maintenance

Tools & Equipment Required

•OBD-II scanner
•Multimeter
•Fuse puller
•Wiring diagram for the CAN bus system
•CAN bus analyzer (optional)

Parts Required

•Replacement fuses (if necessary)
•Electrical connectors (if damaged)

Related Faults

Share this solution

Comments

No comments yet

Be the first to share your thoughts

Back to Generation

Diagnostic Steps

1
Verify the presence of any active or stored trouble codes using an OBD-II scanner.
2
Inspect the vehicle’s fuses related to the CAN bus network for any blown fuses.
3
Examine the wiring harness and connectors between the modules for damage or corrosion.
4
Measure the voltage on the CAN high and CAN low wires using a multimeter.
5
Check the individual modules (ECM, BCM, etc.) for proper operation and connectivity.
6
Use a CAN bus analyzer if available to monitor data traffic and identify communication issues.

Solution

1. Preparation

Gather necessary tools and parts.
Ensure the vehicle is parked on a flat surface and the ignition is off.
Disconnect the negative battery terminal to prevent electrical shorts.

2. Inspect Wiring and Connectors

Tools Required: Multimeter, wiring diagram for the CAN bus system
Inspect the wiring harness connected to the CAN bus for any signs of wear, fraying, or damage.
Check all connectors for corrosion or loose pins. Clean or replace connectors as necessary.

3. Check and Replace Fuses

Tools Required: Fuse puller or pliers
Locate the fuse box and identify the fuses related to the CAN bus system.
Pull each fuse and inspect it visually. Replace any blown fuses with the correct amperage rating.
Reinsert fuses securely.

4. Verify Voltage on CAN Wires

Tools Required: Multimeter
Set the multimeter to measure DC voltage.
Probe the CAN high and CAN low wires at the relevant connectors.
Expect a voltage of approximately 2.5V when the system is idle and around 2.5V to 3.5V during communication.
If readings are outside the expected range, further inspection of the wiring may be necessary.

5. Module Testing

Tools Required: OBD-II scanner, CAN bus analyzer (optional)
Reconnect the battery and turn on the ignition.
Use the OBD-II scanner to check each module for faults.
If modules are not communicating, consider replacing the faulty module or wiring as needed.