TPS test measurement advice please

[The Wanderer]

Hi there. I recently had the diesel fuel pump refurbished and since refitting, I've had the HOLD light flashing. The TPS was changed for a secondhand one which reportedly was working fine, but the flashing HOLD light is still there and a test on the ECU gives code 12, which points to a faulty TPS. I've had a good read around the forum threads and fact sheets but can't figure out the best way to test if the TPS is functioning correctly. I understand that the readings for closed and open are approx. 1.3v and 4.2v but can't figure out where to attach my test meter to check the readings, and whether I can test the TPS whilst the vehicle is stationery. Can anyone advise how to go about this please?

The most similar thread to my problem appears to be this one http://www.igmaynard.co.uk/bongo/forum/ ... t=test+tps, where M Bongo solves the problem by adjusting the TPS position, which I have tried but makes no difference. There is also a thread here http://www.igmaynard.co.uk/bongo/forum/ ... 87#p139787 where Corblimey describes how to test the TPS, but I can't figure out where pin 21 is on my ECU. Is he describing a different ECU? Mine's below the glove box to the left hand side of the passenger footwell in a '95 2.5 diesel.

Thanks

[g8dhe]

Does he not mean 2I pin;

[The Wanderer]

Thanks Geoff, but how does that diagram translate to my ECU please?

[g8dhe]

The ECU is the box in the middle as the 3 in the letters in the middle indicate The bits around it are all the various sensors etc.

[The Wanderer]

I think I see where you mean. The box that says B2-01 ECU(E) that has 3 sets of rectangular blocks in? So which pin? Third pin bottom left of middle block as mentioned in Corblimey's post is 2L, but I thought he said 2l, which looks like it's 4th pin top row of the middle block. But actually, my ECU doesn't look like this. It looks like an upside down version of the one shown in the Diagnostic fact sheet I think.

[The Wanderer]

Here's what my ECU looks like

[g8dhe]

No that is the OBD socket, the ECU is to the right mounted on the firebreak directly in front of the passengers feet,it has 3 separate plugs hence the numbering of the pins on the ECU, each plug is shown with colour codes below the diagram.

Here is a picture of the ECU on a V6 very similar;

[The Wanderer]

Aha, thanks, that makes sense now! The OBD is what I used when I got fault code 12 on dash. Do I need to do test with ECU whilst driving, as suggested by Corblimey, or can the vehicle be stationery?

[g8dhe]

I think you will be find its fine stationery, as its looking at the revs rather than the roadspeed, that only comes into play with the ECU-AT section.

[The Wanderer]

That's great. I couldn't really work out why it would be necessary to drive to test it.

Thanks for your help,

Geoff

[The Wanderer]

Just to complete this thread, I thought I would post what the solution to this issue turned out to be. Rather than the TPS itself, there is a post coming up from the fuel pump that the TPS mounts onto. The post rotates to give the TPS throttle position info and is adjustable. When my pump was reassembled, the post had not been set exactly in the right position, so was sending the wrong voltage to the TPS which in turn was sending incorrect info to the gearbox. The auto gearbox specialist I ended up going to tested the voltage with a meter and then adjusted the post until correct. Problem solved! I gave them the correct approx. measurements as seen in other posts - 1.3v closed, 4.2v open.