Dashboard Warning Lights After an Immobiliser Was Fitted? Here's Why
Timi
You have just had an immobiliser or tracker fitted, and now there are warning lights on the dashboard. It looks bad, but it is often easy to fix.
Safety first
If you see a red warning light, especially brakes, oil pressure, engine temperature or airbag, stop and get it checked before driving. Amber lights are usually less urgent, but should still be looked at soon.
Why fitting hardware can cause warning lights
Modern vehicles are full of control units talking to each other over the vehicle network. When installers work on the car, a few things can upset that:
Low battery during the install
Installs often mean doors open, lights on and the ignition switched on and off many times. That drains the battery. When voltage drops low, control units can log faults and light up warnings.
This is the most common cause. The faults are usually stored codes, not real problems.
Disconnecting modules or the battery
If the installer disconnects the battery or unplugs modules to fit the hardware, some systems log communication faults when they lose contact.
Interference with the vehicle network
Some immobilisers and trackers connect to the vehicle’s CAN bus. If this is done badly, it can upset the messages between modules, causing warnings.
Tapping into the wrong circuit
Connecting to the wrong wire can cause faults in that circuit, for example lighting, ABS or steering lock.
What to do
- Note which lights are on. Take a photo.
- Drive a short distance if it is safe. Some warnings clear by themselves after a drive cycle.
- Check the battery. If it is low, charge it. Low voltage causes a lot of phantom warnings.
- Get the codes read. A diagnostic tool will show which faults are stored and whether they are current.
- Clear stored codes. If they were caused by the install and the system is now fine, they can be cleared.
- Go back to the installer if lights return. A reputable installer will fix it.
Lights that come back
If a warning returns after clearing, there is a real ongoing issue. Do not keep clearing it. Ask the installer to check the connections, especially any CAN bus connections or wire taps.
Will it affect my warranty?
A properly fitted immobiliser should not void your warranty. If an aftermarket install causes a fault, that specific fault may not be covered. See our guide on whether ghost immobilisers void warranty.
Hardwire dash cam installs
Hardwired dash cams can cause similar issues if the fuse tap goes on the wrong circuit. See our guide to dash cam hardwire kits not working.
Choosing a good installer
Most install problems come down to rushed work. Good installers keep the battery supported during the install, use proper connectors rather than twisting wires, avoid safety circuits and check for fault codes before handing the vehicle back.
Traknova installs immobilisers and trackers to a standard process for each vehicle model, and checks every unit before the vehicle goes back to work. See our immobilisers page and our guide to ghost immobiliser installation.
Summary
Warning lights after an install are usually low battery or stored codes from the work. Check the battery, read and clear the codes, and go back to the installer if they return. Do not ignore red lights.