U0168

Lost Communication With Vehicle Security Control Module

Car Fault Codes Network

Can you still drive? With care, short trips only

Who can fix it? Needs a specialist or dealer

Typical repair time 30 minutes – 4 hours

Typical cost SAR 100 to 4,000

What it means

The vehicle security module runs the anti-theft alarm and, on many vehicles, takes part in the immobilizer or in keyless entry and start. This code sets when messages from this module stop reaching the network. The effect depends on the maker: only the alarm may stop working, or the engine may refuse to start if the module is part of the immobilizer system.

Symptoms4

No start, or the engine dies after a few seconds on some vehicles.
Security light flashing or a security system message.
Alarm going off for no reason, or not working.
Keyless entry, keyless start or the remote not working.

Possible causes6

Weak battery or low voltage.
Blown module power fuse.
Loose or corroded module connector.
An aftermarket alarm or remote starter wired incorrectly into the vehicle harness.
Open or shorted network wiring to the module.
Internal module failure or lost programming.

How to diagnose5

Test the battery and measure voltage while cranking, and charge it before any other test.
Use the service information to see which module is the security module on your vehicle and whether it is built into the BCM or the immobilizer.
Try to connect to the module with a scan tool; if it does not respond, check its fuse, power and ground.
Look for aftermarket alarms or remote starters and check how they are wired in.
Check the network lines to the module and compare their resistance with the manufacturer specification.

How to fix5

Charge or replace the battery and replace any blown fuse.
Remove the incorrectly installed accessory and restore the original wiring.
Repair the damaged connector, ground or network wiring.
Have a specialist reprogram or replace the module, then pair it with the keys and engine computer if required.
Clear the codes and test starting, the alarm and the locks several times.

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 battery, fuse or aftermarket device, and reaches the upper end when the module is replaced and programmed with the keys.

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

How is this different from U0167?

U0167 refers specifically to the immobilizer module, while this code refers to the vehicle security module, which may cover the alarm and keyless entry. On some vehicles both functions share one unit, so the two codes appear together.

Can an aftermarket alarm cause this code?

Yes, sometimes. Installing an alarm or remote starter by cutting into the vehicle wiring or tapping the network lines can cut off the security module. Checking and removing it is one of the first steps.

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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