U0104

Lost Communication With Cruise Control Module

Car Fault Codes Network

Can you still drive? Yes, normally

Who can fix it? Needs a workshop

Typical repair time 30 minutes – 4 hours

Typical cost SAR 100 to 5,000

What it means

Another module has stopped receiving messages from the cruise control module over the CAN bus. On vehicles with adaptive cruise control this module is usually the radar sensor at the front of the vehicle, and systems such as forward collision warning may be affected with it. The code usually does not affect the engine, and the cause is often the sensor connector, wiring or power, or damage to the front bumper.

Symptoms4

Cruise control or adaptive cruise control stops working.
Warning message that cruise control or driver assistance is unavailable.
Forward collision warning or automatic braking stops working on some vehicles.
Scan tool cannot communicate with the cruise control module.

Possible causes6

Corrosion or water in the front radar sensor connector because of its exposed location.
Damage to the front bumper or grille after a minor collision affecting the sensor or its wiring.
Blown module power fuse.
Weak battery or unstable voltage.
Open or shorted bus wiring to the module.
Internal failure of the module or radar sensor.

How to diagnose5

Read codes from all modules; if many modules report lost communication, start with the battery and the bus, and if only the cruise control module is missing, focus on it.
Try to communicate with the cruise control module directly with a scan tool; no response points to lost power, ground or wiring to it.
Locate the cruise control module from the manufacturer information, which on vehicles with adaptive cruise control is usually the radar sensor at the front of the vehicle, while on many vehicles cruise control is part of the engine computer, then check its power fuse and measure power and ground at its connector.
Inspect the module connector for water, corrosion or loose terminals, and check the bus wiring to it.
Disconnect the battery and measure resistance between the CAN bus wires at the module connector, comparing with the manufacturer specification to find an open or short.

How to fix6

Charge or replace the battery, and clean and tighten its terminals.
Replace the blown fuse after finding why it blew.
Clean the module connector and repair the ground or damaged bus wiring.
Update the module software if the manufacturer has an update.
Replace the cruise control module if proven faulty with good power and bus wiring, then program and code it to the vehicle.
Clear codes in all modules and confirm the code does not return.

Repair cost

0–500

500–2,000

2,000–5,000

5,000+

In Saudi riyals; the highlighted part is the expected range for this fault.

The cost is low for a fuse or connector, and rises sharply if the radar sensor must be replaced, because it needs programming and calibration after installation.

Prices are rough estimates for common cars at independent workshops and vary with the car and the source of the part.
Prices last updated: September 2026

Frequently asked questions

Is this code serious?

It usually does not affect the engine or normal braking, but assistance systems such as forward collision warning may stop working, so stay alert while driving until it is fixed.

Does the radar sensor need calibration?

Yes. After it is replaced or moved, or after front bumper repairs, it usually needs calibration with dedicated equipment to work accurately.

Why does the code appear after a minor collision or pressure washing?

The sensor and its connector sit at the front of the vehicle, so the impact can affect its wiring or high-pressure water can reach its connector.

This guide is for information only and does not replace an inspection by a qualified technician. If the fault involves brakes, steering, engine temperature, electrics or refrigerant, do not attempt the repair yourself.

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