The 75 and ZT Owners Club Forums - View Single Post - Diesel auto non start

75driver · 7th March 2021, 12:52

Just to finish off this thread....with a positive outcome!😁

Sorry if its a bit long and rambling 🥱.

I took Brian up on his offer to have the ECM checked out.

In the meantime, I did some multimeter checks, from this link by Brian, as found in post No. 2 from CLF. https://www.the75andztclub.co.uk/for...73&postcount=7

Essentially checked the terminals of the Main Relay R4 in the engine compartment fusebox.
Terminals 86 & 87 were at 12.34 V - good.
Terminal 30 showed continuity to pin 1, connector 1 to the ECM - good
Terminal 85 showed continuity to pin 9, connector 1 to the ECM - good.
So all looked good with the wiring.😅

Brians checks revealed that there had been some water ingress to the ECM in the past, but it didnt look too bad. In fact he coded the ECM to his own ZT and ran without problems for over 600 miles.
[FONT=&quot]To eliminate any possible intermittent fault, he transferred the data from my ECM to a known good one and sent it back to me. (Many thanks for the thorough investigation&#128077

.
When i recieved the ECM, i plugged it in....... but no joy. Still showing EP on dash🤬.

Checked again for 12v at terminal 86 & 87 of relay 4...all good.
Checked for continuity on terminals 30 and 85....no joy.😯.
Now this could have been down to my haphazard set up, where i had to use a phase tester connected in series, to insert into the ECM pin connectors, as my multimeter terminals were a fraction too wide 🤔.
Tried several times for continuity without luck, so resigned myself to checking for wire breakages when my fingers werent frozen.😞

Put the tools away, as it was only 3C, and getting dark.
Then thought I should try switching relay 2 (HRW) and relay 4. Bingo....😀😀😀😀.
Funny, I am sure that I had already done this, but knowing me, I probably mixed them up when I had them out, and put them back in the same place!🙄

Anyhow, all running now. Hopefully not coincident with something else.
I suppose i could check by switching the relays again, but probably best to leave well enough alone eh?

Many thanks for all the help and suggestions.

7th March 2021, 12:52	#12
75driver Posted a thing or two Rover 75 saloon, manual. Rover 75 Tourer, Auto. Join Date: Jan 2013 Location: Newry Posts: 1,781 Thanks: 574 Thanked 443 Times in 371 Posts	Diesel auto non start - EP on dash Just to finish off this thread....with a positive outcome!😁 Sorry if its a bit long and rambling 🥱. I took Brian up on his offer to have the ECM checked out. In the meantime, I did some multimeter checks, from this link by Brian, as found in post No. 2 from CLF. https://www.the75andztclub.co.uk/for...73&postcount=7 Essentially checked the terminals of the Main Relay R4 in the engine compartment fusebox. Terminals 86 & 87 were at 12.34 V - good. Terminal 30 showed continuity to pin 1, connector 1 to the ECM - good Terminal 85 showed continuity to pin 9, connector 1 to the ECM - good. So all looked good with the wiring.😅 Brians checks revealed that there had been some water ingress to the ECM in the past, but it didnt look too bad. In fact he coded the ECM to his own ZT and ran without problems for over 600 miles. [FONT=&quot]To eliminate any possible intermittent fault, he transferred the data from my ECM to a known good one and sent it back to me. (Many thanks for the thorough investigation&#128077. When i recieved the ECM, i plugged it in....... but no joy. Still showing EP on dash🤬. Checked again for 12v at terminal 86 & 87 of relay 4...all good. Checked for continuity on terminals 30 and 85....no joy.😯. Now this could have been down to my haphazard set up, where i had to use a phase tester connected in series, to insert into the ECM pin connectors, as my multimeter terminals were a fraction too wide 🤔. Tried several times for continuity without luck, so resigned myself to checking for wire breakages when my fingers werent frozen.😞 Put the tools away, as it was only 3C, and getting dark. Then thought I should try switching relay 2 (HRW) and relay 4. Bingo....😀😀😀😀. Funny, I am sure that I had already done this, but knowing me, I probably mixed them up when I had them out, and put them back in the same place!🙄 Anyhow, all running now. Hopefully not coincident with something else. I suppose i could check by switching the relays again, but probably best to leave well enough alone eh? Many thanks for all the help and suggestions. __________________ 2006 75 Contemporary SE diesel manual (#1) 2003 75T Connoisseur SE diesel auto (For Comfort) 2005 75 Connoisseur SE diesel auto (Marmite duotone ) 2006 75 Connoisseur SE diesel auto (The last one?) 2009 E220 (For a change) 2018 L200 (For Big & Heavy Things) 1976 W114 250 Manual (For Sundays) Last edited by 75driver; 7th March 2021 at 14:09..