Si Click
Well-Known Member
- Posts
- 1,506
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- Lincolnshire
A week or so ago my son's D90 TD5 (10p) lost power, the MIL came on and it threw up a code along the lines of poor crank position signal high. It was close by and driveable at slow speed so it limped home.
When I swapped in a new crank position sensor the plug off the loom basically came apart in my hand. The wire was heavily corroded and one became completely disconnected, I put the failure down to dodgy wiring but left the new sensor in place just in case. There was very little uncorroded wiring from the loom, and trying to crimp terminals to what was left and assemble a new socket in the cramped space behind the engine was impractical. So I acquired some twin core screened cable specified as suitable for CPS, wired it into the ECU plug (including the earth screen), armoured it, routed it neatly to the sensor with a new plug. At each end I kept the screening in place as close as possible to the plugs. All seemed well.
I then replaced the exhaust manifold (which did not go so well), also installing a pyrometer for a 52mm EGT gauge which replaced the clock in the dash. I test drove it for about 5 miles and it was fine.
My son picked it up this afternoon and as soon as the engine started the MIL came on with the same poor crank position signal high code. However, this time there is no loss of power and the MIL is intermittent, not illuminating on every start.
The new sensor is an aftermarket one from Bearmach, so I guess it could be faulty out of the box. If it is still throwing up codes next weekend I will put the old sensor back on.
The only other thing I can think of is that the wire I used has too low a gauge. It certainly seemed thinner than the original wiring. Does anyone know exactly what specification the wire should be and where I can get more suitable screened wire? This is the wire I used; https://www.efi-parts.co.uk/index.php?productID=324
Any other thoughts as to what the problem might be?
When I swapped in a new crank position sensor the plug off the loom basically came apart in my hand. The wire was heavily corroded and one became completely disconnected, I put the failure down to dodgy wiring but left the new sensor in place just in case. There was very little uncorroded wiring from the loom, and trying to crimp terminals to what was left and assemble a new socket in the cramped space behind the engine was impractical. So I acquired some twin core screened cable specified as suitable for CPS, wired it into the ECU plug (including the earth screen), armoured it, routed it neatly to the sensor with a new plug. At each end I kept the screening in place as close as possible to the plugs. All seemed well.
I then replaced the exhaust manifold (which did not go so well), also installing a pyrometer for a 52mm EGT gauge which replaced the clock in the dash. I test drove it for about 5 miles and it was fine.
My son picked it up this afternoon and as soon as the engine started the MIL came on with the same poor crank position signal high code. However, this time there is no loss of power and the MIL is intermittent, not illuminating on every start.
The new sensor is an aftermarket one from Bearmach, so I guess it could be faulty out of the box. If it is still throwing up codes next weekend I will put the old sensor back on.
The only other thing I can think of is that the wire I used has too low a gauge. It certainly seemed thinner than the original wiring. Does anyone know exactly what specification the wire should be and where I can get more suitable screened wire? This is the wire I used; https://www.efi-parts.co.uk/index.php?productID=324
Any other thoughts as to what the problem might be?
