ECU Diagnostics
Also called ECU checking
ECU diagnostics establishes whether the engine control unit itself has a problem, or whether it is reporting a fault elsewhere. We check its power supplies and earths, confirm it communicates on the vehicle network, test its outputs, and inspect its connectors for corrosion and water. Genuine unit failure is uncommon. Most cases turn out to be wiring, earths or a failed sensor, and this test tells you which situation you are in before anyone quotes for a control unit.
Signs you need this
- The scan tool cannot communicate with the engine control unit
- Many unrelated fault codes stored at the same time
- The car will not start and there is no spark or injector signal
- Faults began after flooding, a jump start, or welding on the car
- You have been quoted a replacement control unit and want it verified
Not all of these have to be present, and one of them on its own can mean something else entirely. That is what the diagnosis is for.
What the job includes
- Communication test with the unit and across the vehicle network
- Power supply and earth circuits measured under load
- Output driver testing for the circuits reported as faulty
- Connector pins inspected for corrosion, water ingress and pin tension
- Software version and any stored adaptation values recorded
- Written finding stating clearly whether the unit is at fault
How we do it
Test the communication
We check whether the unit responds on the network, and whether other modules on the same network still communicate.
Measure power and earth
Supplies and earths are measured under load, because a poor earth produces symptoms identical to a failed unit.
Inspect the connectors
Pins are checked for corrosion, moisture and spread terminals, a very common cause of suspected unit failure.
Test the outputs
Suspect output circuits are tested at the unit to confirm whether an internal driver has genuinely failed.
Give a clear verdict
You get a written answer on whether the unit is faulty, with the measurements that support the conclusion.
How we work
The same on every job, which is why we can write it down.
Diagnosis before quote
We find the fault first. A price given over the phone for a noise nobody has heard is a guess.
The price is agreed first
You approve the work and the cost before a spanner is picked up. Extra work means another call.
Parts you can check
We tell you whether a part is genuine, OEM, aftermarket or used, and what each one costs.
Old parts returned
Ask and we will hand back whatever we replaced. It is the simplest proof that the job was done.
Book ecu diagnostics
Fill this in and a person will call you back to confirm the time and the price. Only your name and one way to reach you are required.
You send this
Takes a minute. No payment, no obligation.
We call you
To confirm the car, the time and the location.
Tell us the car and the symptom
We will arrange a mechanic at your location, or a slot at the nearest workshop. No payment until the price is agreed.