Help! My very pampered 95 850 T5 has died at only 160,000 Km! As a dedicated DIY mechanic, without "vadis" resources I'm completely beaten by this one.

The On Board Diagnostics read; Module A Socket 1: 2-1-3 Throttle Position Signal out of range. Socket 2: 1-2-3 Coolant Temp Sensor signal absent or faulty, and 3-1-4 Cam Position Sensor fault. These codes replicate after clearing - ie permant faults.

The car previously started (with some initial mild over revving) and drove, inspite of these fault codes, but now will not even start! The new development is that there is no High Tension Voltage being delivered from Coil to Distributor when cranking. The car had been driven home and would not start following morning.

I'm not entirely convinced that the lack of spark and the Fault Codes are related?

As best as I can determine from wiring diagrams the three Sensors that come up in the codes share a common earth point, but I've been unable to locate it (it may simply be at a connector in the harness). I have checked the harness for continuity back to ECU sockets and there are no other apparent earthing problems within other systems (ie temp guage which shares the Temp sensor works OK).

I had the Hall sensor repalced in the Cam Position unit, hoping that it was the sensor most likely to be critical to the lack of HT voltage, but this has made no difference. The faulty Cam Position Sensor fault code is still produced despite the assurance that it has been tested as OK - which casts doubt over the validity of the other codes?

I've also isolated the coil and can manually excite a healthy spark, which suggests the coil itself is OK, but apparently it is not getting an exciter signal?

I could try replacing the Temp Sensor and Throttle Position Sensor, but I'm not convinced they are actually the root cause stopping the engine starting - as they were NOT stopping it before the HT spark went. I wonder if the multiple codes are actually being triggered by something other than the obvious individual sensors? Any one been confronted with a similar scenario??

My sources of Volvo info are pointing at the ECU itself. Their logic being that it could be a faulty earth within the ECU. This might well explain the fault codes? However, wouldn't there also be a 1-1-2 or similar ECU failure diagnostic fault code coming up if this were the case - especially if the ECU is to blame for the lack of ignition exciter signal to the coil? ( I'm reluctant to out lay the dollars for an ECU for the same outcome as the replaced cam sensor - ie no solution!).

Does any one have any suggestions (hopefully less expennsive than a new or repaired ECU) as the possible sources of fault that might explain the lack of spark when cranking and to shed some light of this aombination of fault codes?

John Harris