wrong ohms reading

[leylanddaf]

put in two new selenoids to a rover75 cdt 2001, a 2/4 brake duty an an epc , they should read between 2.3 and 3.2 but both are reading 16.4,:shrug:.Can any one throw any light on what can be wrong??

[SD1too]

First of all Micky when you say "new" do you really mean new?
If so, check that you're using the correct half of the multipin connector for your measurements and that the circuit is not powered.

Also, in your post you're calling a solenoid an 'epc'? :confused:

Simon

[leylanddaf]

epc is the pressure control solenoid, the two selonoids are brand new.im testing on the 18 female connector nearest front of car and battery fully disconected

[SD1too]

Check that you're not viewing the connector upside down. Use a cable colour as a reference.

Simon

[leylanddaf]

am i rite in using the female ends, does high resistance mean low voltage?

[SD1too]

am i rite in using the female ends ...
You need to use the end whose loom leads to the gearbox. I don't know which that is without looking myself.
... does high resistance mean low voltage?
All you need to know is that the resistance measurement should correspond with the figures you have.

Simon

[leylanddaf]

i am doing test correctly, im at a real loss why im getin so high a reading,have you any idea whats causing that??

[murphyv310]

Hi.
Firstly ensure your Meter reads zero when the prods are shorted together. if OK make doubly sure that you are connecting them to the correct point, also make sure there is no corrosion (green in colour) on the connectors and the solenoids are properly connected.
A high resistance here will mean the solenoids will most likely not operate as they will not pass sufficient current.

[leylanddaf]

just going to have to check all electrics:mad:

[leylanddaf]

would you believe it, after changing transmision oil ,puting on a new transmision reach sensor/switch. two new selonoids, my problem all the time was my glow plug relay.:). thanks all for your help, im really glad i persevered should have got my multimeter sooner:}

[SD1too]

Micky,

How could symptoms of a faulty glow plug module have led you in the first place to the automatic gearbox? Just curious, that's all.

Simon

[leylanddaf]

my fault first day was the car jumping in to third gear.Seems now it was an electrical problem,the high ohms reading on the new selonoids led me to see there was a intermitent power supply problem.ive ordered a new relay and im sure im rite for when i cleaned and played about with it the gear box took third gear for about 2 mins, and put EP on dash at different times than before, after workin with it the second gear jumped like third used to do. seems ive found culprit:}

[SD1too]

... the high ohms reading on the new selonoids led me to see there was a intermitent power supply problem ...
Sorry Micky but that's not correct. Any problem that you might have with your glow plug relay, or power supply, cannot possibly affect the resistance reading of an automatic gearbox solenoid coil.

You must be taking the reading incorrectly or the replacement solenoids have been incorrectly fitted, are faulty or of the wrong specification.

Simon

[leylanddaf]

i cant argue, these multiplex wireing systems are complex, ive read another blog where a similar problem was sorted with a new glow relay module.the module is 8 pronged and i believe it does supply power to the gearbox ecu, tuesday will tell if its the cure. i cant understand how workin with it altered my problem if its not part of it??

[SD1too]

... these multiplex wiring systems are complex ...
Neither the gearbox solenoids nor the glow plug module is on the multiplex system, so you've no worries there.

... a new glow relay module ...the module is 8 pronged and i believe it does supply power to the gearbox ecu ...
I've checked the MGR circuit diagram and it doesn't. Whoever told you that is telling porkies. The EAT ECU receives it's supply from the main relay via fuse 4.

Now, I think I may have found your problem.
am i rite in using the female ends ...
According to the MG Rover wiring diagram it's the male part of the 18 pin connector which leads to the solenoids. Pin 18 is the common terminal and pin 15 is the pressure control solenoid, pin 16 is the 2/4 duty solenoid. So try again and report back. :)

Simon

[leylanddaf]

ok thanks simon, i have been doing my readings on the female but i will test tomorrow on the male. :)

[leylanddaf]

youve been proved right simon. my readings on the male end of the test plug are perfect. if the new glow plug module isnt a sucess im snookered. i had great bother changing the gear oil and i never did find the hexagonal plug,to test level.at least now i can eliminete selonoids as cause.Many thanks again for your input.

[SD1too]

youve been proved right simon. my readings on the male end of the test plug are perfect.
Good! :D Glad to be of service.
i had great bother changing the gear oil and i never did find the hexagonal plug,to test level.
Two points on this:


Which automatic transmission fluid did you use? There are only half a dozen or so which meet the required specification.
To find the level checking plug, locate the selector cable on the underside of the gearbox. Beside the rear of the cable gaiter you should see a 5mm female Allen headed plug. That is it. Note that it is on the horizontal underside of the gearbox. Do not undo anything on the side. Do you have the instructions for checking the level?


Have you measured the resistances of the solenoids which you removed? Were they out of spec.?

Simon

[leylanddaf]

the transmision oil i used was .PLANET aqm multi purpose oil.it said it suited a dexron 2 type fluid. must try and locate that almond key hole and test level, and no i dont know check procedure:). i wont get my hands on those two old selonoids till monday ,ill check them then.that test plug was very deceiving bet a lot of people go wrong on it:}

[SD1too]

the transmision oil i used was .PLANET aqm multi purpose oil.it said it suited a dexron 2 type fluid.
That's the wrong fluid Micky. For a start it's a mineral oil, and the Rover recommended ATF is fully synthetic. You need one of these:

MG Rover/X Part GUL 1805 or VYK 000 040
Land Rover STC 50531
Texaco Havoline Multi-vehicle ATF
Fuchs Titan ATF 4400
Carlube ATF-U
Valvoline Maxlife ATF
Ravenol ATF JF506E

The MG Rover/X Part fluid is available from Rimmer Brothers. For Ravenol ATF JF506E see www.ravenol-shop.co.uk

The problem is that you've now got original used synthetic fluid mixed with incorrect new mineral fluid. This is because when you drain an automatic gearbox, a substantial amount of fluid remains in the torque converter. There is a way of pumping it all out though, but you have to be careful that the gearbox doesn't run dry. Do you want to try this? It will involve quite a bit of expense buying the correct fluid.

Simon

[leylanddaf]

good god, can you post me the technique to drain the box. maybe thats why she wouldnt move up the gears do you think. il get ten litres of one of them from your list on monday. simon your help on this matter is really appreciated!

[SD1too]

... can you post me the technique to drain the box.
Remember that this procedure is not from MG Rover. I think it was devised and first tried by a 75 and ZT Club member from the Netherlands or Sweden. The author of the post is Beinet1 who has successfully repaired his automatic gearbox and saved K1.8 engines with blown head gaskets, so he knows his stuff! Here's the link:

http://www.the75andztclub.co.uk/forum/showpost.php?p=1100558&postcount=1

In the second photograph, on the far right of frame, you'll see the Allen headed level plug which we were talking about earlier.

SouthLakesMinis.com used to do the MGR VYK000 040 (5 litres) of fluid for a good price.

I can't offer you a guarantee that changing the fluid is going to solve your problems, but I sincerely hope that it does! ;)

Simon

[leylanddaf]

thats great info simon, i believe youve put me on the rite track:)

[leylanddaf]

blast, have put on glow plug relay module and changed transmision oil again. this time i used reccomended car lube ATF-U, but to no avail.at a loss now what to do , at 2001 think now il just scrap her:getmecoat:

[SD1too]

... changed transmision oil again .. used reccomended car lube ATF-U, but to no avail.at a loss now what to do ..
Did you follow exactly the MG Rover level checking procedure?

If so, judging by your previous threads, it seems that you have eliminated the possibility of a faulty solenoid. The problem may well be the common one of a cracked reverse piston as described here (http://www.the75andztclub.co.uk/forum/showpost.php?p=1367698&postcount=2).

Simon

[leylanddaf]

going to have to call it a day on this, cant keep throwing good money after bad, many thanks simon ,

[leylanddaf]

on the three times now ive drained the box. The instructions say put a hose on the bottom cooler stud and drain cooler , but every time nothing came out there with me , it always flew out of the bottom black pipe that id taken of ! does that tell any body anything? it is possible that shift selonoids A B C can stick or do they get blocked up?

[SD1too]

It sounds as if the gearbox hoses on your car are connected to the cooler the opposite way around. So long as you managed to pump out all the old fluid, it doesn't really matter.

Micky; there are three known causes of trouble with the JATCo automatic transmission: incorrect fluid and/or level; a faulty solenoid and a cracked reverse piston. Provided that you are satisfied that you have tackled the first two satisfactorily, then that leaves the reverse piston. JATCo now supply a redesigned piston to cure the problem, and it can be fitted without removing the transmission from the car. A competent automatic gearbox repairer should be able to do this work for you at reasonable cost; certainly less than the expense of buying a replacement car. If you want to have a go yourself, you can read other members' accounts, together with photographs, on this club forum.

Simon