OK first some history, the Van is a Clean 91 EXT 4WD, 120000KM with service records used for highway commuting weekly from Niagra to Toronto, 1 previous owner, and it smelled of dogs, the Van has had some issues howeer the most worrying is the fact is the Transfer Case Module was missing, So today I picked up one and pulged it in, Now I have the light that says eletronic 4 wheel drive on the bottom right hand of the dash flash twice every 10 seconds, I know there must be a problem but does anyone know what to start looking at, does anyone know how to interpret the code or is it a dealership thing

 

Hello,
According to a ford CD manual, you should check the connectors on the transfer case especially the ones on top. the code you said pertains to clutch circuit continuity troubles. Hopefully it is a wiring connection problem. It could have been disconnected because of an internal transfer case problem with the viscous clutch. Does it go into 4 wheel drive?

 

Unplug the clutch at the transfer case and ohm it out. It shoud read a few ohms, not more than 5 or 6. If it's open, you have a problem with the clutch coil. If not, the problem is in the wiring before it.

 

E4WD CLUTCH -- TEST F


F3 CONTINUITY TESTING OF CLUTCH CIRCUIT


l Check for an open on the clutch circuit:

-- Turn the ignition switch off.

-- Disconnect the module harness connector from the module.

-- Set the ohmmeter to the 20 ohm scale.

-- Shake the module harness connector and check the resistance between MHC pin 14 and pin 13.



Resistance is between 1.5 and 4 ohms
GO to «F4».

Resistance is below 1.5, above 4 ohms
REPAIR open in clutch circuit or REPLACE clutch.
__________________________________________________ ______________________



E4WD CLUTCH -- TEST F


F4 VERIFY THE CLUTCH COIL ENGAGES


l Check the clutch by powering the circuit:

-- Disconnect the module harness connector from the module.

-- Connect Clutch Coil Locking Tool D91T-50-CLT or equivalent to the MHC. If tool is not available, ground MHC pin 13 to ground.

-- Jumper MHC pin 8 to MHC pin 14.

-- Verify clutch engagement by test driving vehicle in tight turns and noticing driveline wind-up (driveline wind-up is noticed through steering wheel feedback or wheel hop).



Clutch engages (driveline wind-up)
REPLACE the control module.

Clutch does not engage (no driveline wind-up)
REPLACE clutch or look for a mechanical failure in the system.

 

I'll get onto that after the weekend, god I love forum's like this. I don't think it goes into 4WD but when I was repalcing teh g/box seal , I had all 4 wheels off the ground, on turnong the rear to get to the prop bolts the fronts also turned, hence why I never thought there was a problem in the first place. I'm guessing usually the fronts have some drive by the design of the system, possibly 30% and this is so with the module removed, as it made no difference to drive I guess the PO was happy with the light not flashing, I thought I felt a slight increase in the steering when I pluged the module but maybe that was wishfull thinking as it feels no different now. If there is a problem with the clutch I guess it will be a trip to Mr Transmission as this is unchartered teratory for me, either that of a decient manual as the Haynes one is Poo! I remember when Haynes used to tell you everything, over the past 15 years all they seem to do is point you to the nearest dealer. If I can manulayy lock up the 4WD when I need it then that would be great aswell. Just to clarify the plug I'm testing from is teh one that plugs into the module I have just put in, or is it one under the van??? just so I don't go looking under there in teh snow and feelk a compleate idiot when it's the one under the seat.
Thanks for teh replys.

 

First check with your local ford dealership. There was a recall on the transfercase half on the aerostars. It may still be in effect and available for your vehicle. Have them run what is called an OASIS, the service writer can do this for you. If this is still under the recall, you should be able to talk them into replacing the parts at you cost for the parts and a SMALL fee for labor, since they have to practically disasemble the t-case anyway to do the recall.

you are checking the plugs at the module and recording the ohms that you get there from the t-case/clutch.

If you need any more help, feel free to Private message me.

 

I have done hundreds of these t-cases repairs either under the recall or warranty or customer pay. There is also a way to install a switch in the battery positive to make your vehicle a 2x4 or flick the switch and it is full 4x4 and no more variable electronic 4x4.

 

OK I give in Pin count is??? with the 2x3 pins facing upwards looking directly at the plug the two bottom pins on the far right givr mr 1 ohm and the two on the bottom row far left give 2.8, I am presuming that I have it right that it goes something like this
o o o ---------------- o o o
1 2 3 ---------------- 4 5 6

0 - 0 - 0 - 0 - 0 - 0 - 0 - 0
7 - 8 - 9 - 10 11 -12 13 -14
Hope this works, if so then 13-14 give me less than the required 1.5, I know temp doesn't help and it's -05 at the moment. Not that it would make a great difference. If this is the correct pin out should I o ahead and bridge the jumpers and see if it activates the 4WD, I don't want to go jumping the wrong pins so I guess I'll have to make sure I've got those right first.

 

actually flip your numbers to this.

14 13 12 11 10 9
0---0---0-------------0---0--0

0--0---0--0--0---0---0--0
8 7 6 5 4 3 2 1

1- (dg/w) Front axle speed sensor (-)

2- (db) Front axle speed sensor signal

3- (gy) Front axle speed signal (+)

4- (w) Indicator control

5- (r/w) Park/nuetral position switch input

6- (lg) Brake on/off (BOO) input

7- (bk/w) Ground

8- (bk/w) switched power

9- (lg/r) rear axle speed sensor (-)

10- (br/w) rear axle speed sensor signal

11- (gy/r) rear axle speed sensor (+)

12- (bk/w) Ground

13- (o) Clutch solenoid (-)

14- (br/y) Clutch solenoid (+)

So the test you did is a good test but of the - and signal of the front axle speed sensor and didnt hurt anything. Here is the complete pin out test for the clutch circuit.

A question that has been unanswered is, "Does it go into 4X4 at all?"

E4WD CLUTCH -- TEST F


F1 BAD OR INTERMITTENT POWER TO CLUTCH


l Check the voltage at the clutch connector:

-- Disconnect the clutch harness connector from the clutch line on the transfer case housing.

-- Set the voltmeter to the 20 VDC scale.

-- Turn the ignition switch to on.

-- Shake the clutch harness and check for battery voltage between the clutch connector pin and chassis ground.



Voltage is steady or intermittent
REPAIR short to B+ on the clutch circuit or REPLACE control module. REFER to the wiring diagrams in this section.

No voltage
GO to «F2».


E4WD CLUTCH -- TEST F


F2 CLUTCH CIRCUIT SHORT-TO-GROUND


l Check for a short-to-ground on the clutch circuit:

-- Turn the ignition switch off.

-- Disconnect the module harness connector from the module.

-- Set the ohmmeter to the 20 ohm scale.

-- Shake the module harness connector and check the resistance between MHC pin 14 and chassis ground.



Resistance is intermittent or below 1 ohm
REPAIR short-to-ground on the clutch circuit. REFER to the wiring diagrams in this section.

Resistance is above 1 ohm
GO to «F3».


E4WD CLUTCH -- TEST F


F3 CONTINUITY TESTING OF CLUTCH CIRCUIT


l Check for an open on the clutch circuit:

-- Turn the ignition switch off.

-- Disconnect the module harness connector from the module.

-- Set the ohmmeter to the 20 ohm scale.

-- Shake the module harness connector and check the resistance between MHC pin 14 and pin 13.

Resistance is between 1.5 and 4 ohms
GO to «F4».

Resistance is below 1.5, above 4 ohms
REPAIR open in clutch circuit or REPLACE clutch.


E4WD CLUTCH -- TEST F


F4 VERIFY THE CLUTCH COIL ENGAGES


l Check the clutch by powering the circuit:

-- Disconnect the module harness connector from the module.

-- Connect Clutch Coil Locking Tool D91T-50-CLT or equivalent to the MHC. If tool is not available, ground MHC pin 13 to ground.

-- Jumper MHC pin 8 to MHC pin 14.

-- Verify clutch engagement by test driving vehicle in tight turns and noticing driveline wind-up (driveline wind-up is noticed through steering wheel feedback or wheel hop).
You can also raise the complete vehicle on jack stands (think Safety) and do this test.


Clutch engages (driveline wind-up)
REPLACE the control module.

Clutch does not engage (no driveline wind-up)
REPLACE clutch or look for a mechanical failure in the system.

 

Hmmm, OK the ohmage is 0.00 so I'm guessing that there is a problem with the clutch, the first 2 tests will have to wait untill tomorrow when the weather is better as the flouressent lights won't even come on now, i was going great untill on my way back from snowboparding I heard a grumble every time I slowed down so a quick u-turn saw me travelling home with new pads, unfortunatly I have to order some new discs as well now as the metal has kissed the back of one and scorred it pretty badly, the problem, was the old pads were so old they had crumbled and more so at one side causing the backing to be at a 15 dedgree angle and the edge had just come into contact with the disc, it may have been doing it all week (I only just put a CD player in a week ago and before then there was no music at all), sods law it happened now, still it was an easy fix and everything came apart easily apart from the wheel bolts but they have copperslip on them now. I'll have a play under the van for the connection to do the first test, I'm wondering (I havn't been under there and I forget what it looks like) if the solenoid plug is on wrong or even not connected, I changed the front seal on the box and when it went a month lated I had the box reconditioned and the fault was the oilpump, I noticed there were a few bolts left loose (like the stabelizer bar and the one that holds the exhaust system), and a few other bits left loose (I didn't complain as I drpped the van off in the morning and was on the road again by 3pm for just under $600CAD and it has been great ever since. So they might have left it unplugged as I'm sure the 16 year old apprentice got the job of doing everything back up. I live in hope, but I'm pretty sure it's going to be the clutch itself.
After reading those tests I'm surprised it doesn't have.
F5
REPLACE CLUTCH DAMMIT.!

 

have u got a wiring diragram on how i can make my van a 2x4 or 4x4 ??
im sure enquiring minds would like to know how lol

 

Looking at teh wire pin out, and the way to test the system, it seems you need to put a +ive power to pin no.14, this is usually done as a switched operation and as the test sudgests you bridge the switched power to the clutch solenoid +ive I'm guessin thats the way to do it, that way you can keep it hooked up for automatic selection as well. Howver I'm quite often way off and have absolutely no expierience with 4WD or automatic gearbox's so I'd wait for conformation on that one.

 

Its no joke. you just need to put a switch on the power side to the 4X4 module, the vehicle I did this to was locked in full 4X4 all the time because of the module and the customer didn't have the 200-300 dollars to replace the module so I installed a switch so they would be in 4X2 when off and 4X4 when on. It is very simple once you understand how this electronic system works in the Aerostar.

 

well x l r 8 you never did answer the question of does the 4X4 system work even though the light is flashing?

 

Err, I'm not sure, I have not got stuck and I can't persuade my wife to nail it on the ice to see if the fromts are turning, there is some drive going to the fromt, I don't think it's locked, I had to remove the front wheels and there was enough drag to undo the wheel bolts throught the 4WD system as botht the front wheels were airborne, there is definatly resistance between the rear and front wheels, I just don't think the clutch locks the wheels, I can't test for binding as the ground is a couple if inches of ice at the moment so it just slips, I do have a fair amount of control in snow and Ice and although the rears are defiantly shaking loose and the back end steps out, it still goes in the direction I point it in and this may be due to weight rather than the front wheels moving, are you sugesting jumping the pins and seeing if the fronts lock up?? I was planning to do that tomorrow and if it did I was going to ask how to rig it onto a switch system, however I feel that as the 13-14 pin showed an open circuit it will be elsewhere, did I ever have 4WD?? I don't think so, but then again I went from a sports car weighing 1250 kgs with summer yoko tyres to an Aerostar weighing as much as a school bus with All-season continentals, I only questioned the 4WD system when I reversed into a deep pocket of snow last month and had a lot of trouble getting out, the rears would spin and the fronts did nothing, with some gental rocking it finally pulled it'self out but doubt had entered my mind, then I saw the post mentioning the module and I remembered seeing what I thought was a connector for electric seats or something hanging under the seat with nothing attached, and here we are. with all 4 wheels in the air I can turn the rear and the front will turn, this is why I never originally questioned the fact that it was 4WD. Does that make sence?? I hope so but in my world I never know.