Hello Stuart.
Here is a ECM fault finding flow chart.
I have a '99 S70 2.5 20v Non turbo with the ETS and MIL on. I got 3 fault codes, all pointing to a bad TCM - the throttle pot.
DTC's read:
P1043=ECM-9520 Accelerator pedal (AP) position sensor, Faulty signal
P1020=ECM-902B Throttle unit communication, Faulty signal
P1059=MIL requested by the throttle unit
In the meantime I spent 130 quid on a 2nd hand yellow label replacement throttle body. Didn't fix! Updated part number to the original white label part number.
Gonna look for a new throttle pot now
So I have a supposedly good white label TCM for the inlet manifold.
In the meatime go to fleabay and search for a T69 OBD2 scanner. I bought one from
www.beatthegarage.co.uk for 75 quid.
Martin