Cranshaft sensor wiring advise please

richyl · 17th June 2021, 12:13

Hi all ,
Thanks for your help so far on the starting issues in my previous thread. Ive done some checks on the wiring.
I have stripped back the insulation on the 3 wires going to the crankshaft sensor and connected a meter between this bare section of loom and the plug pins this is what I've found.
Looking at the plug with the release clip on the top blue/brown left Pin. Purple/Blue centre pin and pink/blue right pin.
Left pin bl/br give continuity on correct pin and the right pin.
Centre pin pu/bl gives continuity on correct pin and right pin.
Right pin pk/bl gives continuity on the correct pin only.
I don't have a wiring diagram and electrics are not my specialist subject. Any advice before i buy the replacement loom YSB11400.
Thanks again
Rich

SD1too · 17th June 2021, 13:31

Hello Rich,

Unfortunately continuity tests on the crankshaft sensor won't help you because it's a Hall Effect device containing electronics.

The best you can do is to release the connector from the sensor and check that each terminal from the connector to the ECM reads zero ohms. That will tell you whether you have wiring damage. I believe that on your 1.8T this loom passes close to the exhaust so that's a likely scenario.

Simon

trikey · 17th June 2021, 16:17

If the wiring from the crank sensor has been cooked, you will have ecu damage as well I’m afraid.

vitesse · 17th June 2021, 17:50

Quote:

Originally Posted by trikey

If the wiring from the crank sensor has been cooked, you will have ecu damage as well I’m afraid.

Apologies to OP, but does this risk apply to the 1.8T too?

I've been trying to hep a local owner (1.8T), run T4 ECU/EMU checks (nothing), updated the software but it still won't run properly.

Regards

trikey · 17th June 2021, 21:29

Yes it’s the 1.8t that suffers ecu failure when the crank sensor wiring is arced over.

vitesse · 17th June 2021, 21:46

Many thanks for the reply, guess the ECU doctor might need a call. Think it funny though that nothing came up on the now mobile T4 but this car has been a nightmare - readers might recall the EWS and wiring problem. (https://the75andztclub.co.uk/forum/s...d.php?t=312290).

Keep well

richyl · 26th June 2021, 08:17

Hi All,
Thanks for all the help I've received. Just a quick update on progress.As you know i replaced the crank sensor a week ago and was getting no signal from it.
I have now cut off the old plug along with a good length of cable and soldered in this lead (Harness link-engine - 260mm - YSB114000 - Genuine MG Rover). The car started last night after fitting it and again this morning. I am hoping this solves the intermittent issues i've had with it. I will put some miles on it this weekend and hopefully no breakdowns.
Regards
Rich

Yorkshire GOC · 26th June 2021, 08:34

Quote:

Originally Posted by vitesse

Apologies to OP, but does this risk apply to the 1.8T too?

I've been trying to hep a local owner (1.8T), run T4 ECU/EMU checks (nothing), updated the software but it still won't run properly.

Regards

Those wires look cooked to me so as Trikey says the ECU is possibly goosed.- i have re-sheathed mine with this stuff - and maybe a coincidence my MPG increased to 31

https://www.ebay.co.uk/itm/SILICONE-....c100005.m1851

17th June 2021, 12:13	#1
richyl Avid contributor Rover 75 V6 Launch Spec and ZT 160+ Join Date: Jan 2012 Location: Swansea Posts: 126 Thanks: 0 Thanked 5 Times in 5 Posts	Cranshaft sensor wiring advise please Hi all , Thanks for your help so far on the starting issues in my previous thread. Ive done some checks on the wiring. I have stripped back the insulation on the 3 wires going to the crankshaft sensor and connected a meter between this bare section of loom and the plug pins this is what I've found. Looking at the plug with the release clip on the top blue/brown left Pin. Purple/Blue centre pin and pink/blue right pin. Left pin bl/br give continuity on correct pin and the right pin. Centre pin pu/bl gives continuity on correct pin and right pin. Right pin pk/bl gives continuity on the correct pin only. I don't have a wiring diagram and electrics are not my specialist subject. Any advice before i buy the replacement loom YSB11400. Thanks again Rich

17th June 2021, 13:31	#2
SD1too Doesn't do things by halves Rover 75 2.5 Connoisseur Auto (1999) Dealer launch model. Join Date: Mar 2007 Location: Former Middlesex Posts: 20,504 Thanks: 1,587 Thanked 3,749 Times in 3,181 Posts	Hello Rich, Unfortunately continuity tests on the crankshaft sensor won't help you because it's a Hall Effect device containing electronics. The best you can do is to release the connector from the sensor and check that each terminal from the connector to the ECM reads zero ohms. That will tell you whether you have wiring damage. I believe that on your 1.8T this loom passes close to the exhaust so that's a likely scenario. Simon __________________ "Whatever is rightly done, however humble, is noble." Sir Henry Royce.

17th June 2021, 16:17	#3
trikey Premium Trader Rover 75 Join Date: Nov 2010 Location: Devon Posts: 33,808 Thanks: 8,837 Thanked 14,831 Times in 8,030 Posts	If the wiring from the crank sensor has been cooked, you will have ecu damage as well I’m afraid. __________________ Lest we forget..

17th June 2021, 21:29	#5
trikey Premium Trader Rover 75 Join Date: Nov 2010 Location: Devon Posts: 33,808 Thanks: 8,837 Thanked 14,831 Times in 8,030 Posts	Yes it’s the 1.8t that suffers ecu failure when the crank sensor wiring is arced over. __________________ Lest we forget..

17th June 2021, 21:46	#6
vitesse I really should get out more....... Rover 75 Saloon Join Date: Jul 2011 Location: Gävle Posts: 2,551 Thanks: 395 Thanked 823 Times in 652 Posts	Many thanks for the reply, guess the ECU doctor might need a call. Think it funny though that nothing came up on the now mobile T4 but this car has been a nightmare - readers might recall the EWS and wiring problem. (https://the75andztclub.co.uk/forum/s...d.php?t=312290). Keep well

26th June 2021, 08:17	#7
richyl Avid contributor Rover 75 V6 Launch Spec and ZT 160+ Join Date: Jan 2012 Location: Swansea Posts: 126 Thanks: 0 Thanked 5 Times in 5 Posts	Hi All, Thanks for all the help I've received. Just a quick update on progress.As you know i replaced the crank sensor a week ago and was getting no signal from it. I have now cut off the old plug along with a good length of cable and soldered in this lead (Harness link-engine - 260mm - YSB114000 - Genuine MG Rover). The car started last night after fitting it and again this morning. I am hoping this solves the intermittent issues i've had with it. I will put some miles on it this weekend and hopefully no breakdowns. Regards Rich