Boxer

Boxer

Active Member
Had the td5 for 5 weeks now 2 and a half of which it hasn't started. Got that sorted, as I predicted a combination of blocked tank filter and leaking fuel filter gasket. Should have done it myself but then I wouldn't now have a collection of electrical bits for free.
Got back on saturday drove home nice. Parked up and left it for a few hours. Nipped out to the shops and on the way back it suddenly lost power then refused to respond to the throttle.
Rang the garage and crawled down there today after the school traffic. Before I took it in I checked some voltages. The 5v supply to the tp sensor was reading .2v and the two sensor outputs added up to .2v and varied when I moved the pedal. So I concluded that the tp sensor was probably ok . The garage had it all day and were at a loss. Then late on in the day they rang and said it was fixed. Walked down and they said that unless calling it a ' useless piece of ****' qualified as a fix they really had no idea what it was. My money is on a poor/intermittent 5v supply from the ecu. Any thoughts?
 
More likely you've got some bad earthing points round the engine compartment, ECU's seem to be fairly reliable, and as yours is an intermittent problem, it looks electrical.

Where did you reference your DVM to when measuring the voltages?

Peter
 
what you can DIY easy: there are 3 earth points on a "rail" near the battery toward the wheelarch, check those, check for oil in the ECU's red plug and give contact spray in the black plug
 
Pin in TPS feed from ecu, earth to the battery terminal.

I can get the logic of electrickery but not too experienced with electronic cars. Other cars are a 300tdi defender and a diesel VW T25.

I suppose I really want to know , if the voltage to the TPS drops does it cause the symptoms?

Injector loom changed even thought here was no oil around the ECU.
 
Boxer said:
if the voltage to the TPS drops does it cause the symptoms?
Click to expand...

yes, there must be around 5V supply there, then the sum of track 1 and 2 must be = with the supply. See attachment
 

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Got that thanks. Tested again today and it is spot on 5v on the supply, not too bothered about the balance as it is running. So what could cause the voltage on pin 14 to drop to less than 1v (not 0v) then magically come back up again? I'm not understanding how a bad earth would cause this or am I missing something? I checked the voltage about 2mm from the plug at the ECU.
 
that's why i said to contact spray the black plug... a bad earth to ECU would disturb the whole software and could cause various misbehaviours... also the wiring to TP sensor goes through a header C0287 pins 7,6,7,8,9,10 which could have bad contacts(this header is insulated into the harness)...unless it's an ECU internal fault
 

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Dropped to tickover again this morning just before motorway thank god. I now have a chance to check wires .ecu is only sending less than 1v to the tps not checked but what else might be affected by a bad earth to ecu that I can check? Its a shame because when it runs it runs well.
 
Boxer said:
Got that thanks. Tested again today and it is spot on 5v on the supply, not too bothered about the balance as it is running. So what could cause the voltage on pin 14 to drop to less than 1v (not 0v) then magically come back up again? I'm not understanding how a bad earth would cause this or am I missing something? I checked the voltage about 2mm from the plug at the ECU.
Click to expand...

a bad connection or loose pin can, i had a similar fault on a Merc Sprinter, it was a loose pin in the ecu plug, took ages to trace it to there as it ran fine then would intermittantly stall,
 
Spend a few hours on it yesterday I can't get 5 volts at the ecu pin for the supply voltage. but the two sensor pins add up to approximately 5 volts. In desperation to prove something I cut the supply wire from the ecu and the sensor pins still had voltage on them? I'm in Africa now so I've rung the c*** who sold it to me and told him to get it sorted before I get back. I don't mind paying a bit just want a nice drive turning into a reliable drive.
 
Does the engine management light come on ? I changed my clutch and fly wheel on mine and moving stuff about under the bonnet. I broke a earth and it would be driving fine the go to tick over wouldn't let me rev. It was a earth by the battery replaced it and its not happened since hope this helps


Joe
 
Ta for that. It would appear its fixed, until the next time. The wiring around the MAF appears to be the problem but when I messed with this I fixed it and can't make it fail again. Going with a theory that if one of the 5v sensor supplies goes to earth it will cause the rest of the supplies to go wonkey. Next time it happens Im thinking i will test all sensor supplies and cut each one until the rest come back to 5v.
 
Right put the fault reader on it and deliberately shorted the ambient sensor 5v supply. MIL light and no throttle response. Ambient sensor fault followed by driver input fault. exactly as the sensor was reading previously. Switch off switch on all well. Repeat, same effect. New wire from pin 8 on the red plug to the ambient sensor. Going to Doncaster tomorrow not overly confident. but just goes to show that what is the obvious answer isn't always.

Suspect there is only one 5v supply to all sensors and when any of them short it can show up lots of different faults.
 
Got all the way over the Woodhead pass and into Doncaster. Parked up popped the bonnet and there is 'water' (water and diesel?) all over the turbo side of the engine and its pouring out of the soundproof felt on the underside of the bonnet. No sign of a leak.

Went and did the job and then set out. stopped about ten times before Barnsley and ended up leaving it with West/South? Yorkshire 4x4 (I've got their number) anyone know them , they seemed to be accommodating lads and they tried really hard to sort it. Anyone on here know them. Should I get it towed home/off a cliff or will they be OK?
 
Got home and remembered the AA! Treked back to Barnsley Saturday and got it recovered to the garage. Stuck him with a letter rejecting the vehicle and we nave done a deal on a Range Rover diesel and cash back.

Should pick it up next week. Wait to see how that goes.
 
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