Thread: Logged fault codes your opinions please.

Not sure if there is a reference manual someplace for TestBook. This may have a good description of the fault codes.

With so many circuits throwing faults I suspect the 1% reference voltage fault may be the key. It is probably a 5volt reference used for all the sensors. If the reference goes tits up then all the sensor outputs that rely on that reference will also throw errors.

The multiplexer probably takes several sensor inputs and feeds then (one at a time) to the ECU processor to be digitised. This all happens fast enough that in a practical sense all the sensors are sampled in real time and it only requires one 'sampling unit' inside the ECU = cheaper

Driver demand is probably throttle related but that still comes back to the reference voltage being wrong.

I don't know if anybody has a schematic for the ECU ? Probably some seriously wishful thinking.

Maybe see if you can borrow an ECU to see if the fault is isolated to the ECU or your multiple sense circuit failures.

** Don't forget to write down your injector codes before you pull the old ECU **

I think the key fob's are programmed to the BCU ? But that is just a guess. If they are programmed to the ECU then you may need access to a nanocom to pair your fob's with the new ECU.

Regards,
Pete

Edit
I wonder if a short circuit in one of the sensor circuits would pull the reference voltage down. Maybe try unplugging the sensors and checking for low resistance to ground and between wires.

Originally Posted by Pacemaker

Hi guys,
I've got a disco 2 td5 auto 99 model. I cleared the codes on fri Arvo and rechecked em again just now. My airflow meter does not work at all. So I expect some of these codes but not all of them. I'm not using nancom I'm using Launch scan tool and the codes are
Manifold pressure circuit fault
Inlet air temp circuit fault
Multiplex input circuit fault (what does this mean)?
1% reference voltage log. ??
Driver demand 3 fault logged.
Ambient pressure circuit fault.

These codes always come back after driving several kms. The ones I'm not sure about are multiplex input and driver demand 3. Any ideas what these could be

My abs always comes back with
pump failure 1.
Pump failure 3.
Shuttle valve switch failure.

I have no eng or abs lights on the dash coming on either.
All help appreciated. Thanx. Michael.

Hey Michael,

Do you get those faults with both your original ECU and the TRS one. The TRS never logged any faults here through the Nanocom.