• Welcome Visitor! Please take a few seconds and Register for our forum. Even if you don't want to post, you can still 'Like' and react to posts.

4x4 wont engage; what else could it be?

MarkDru

New Member
Joined
Dec 31, 2020
Messages
10
Reaction score
2
Points
3
Location
Scituate, MA
Vehicle Year
2002
Make / Model
Supercab 4x4 XL
Transmission
Automatic
New forum user with a 2002 XLT Supercab 4x4. Many thanks to the forum users who have posted so much valuable information and advice.

I cannot get 4wd to engage after spending a good amount of time on the forum and under the truck. Here is where I am:

1. All fuses and relays are ok
2. New transfer case motor. New 4wd switch.
3. Replaced transfer case module with junkyard unit
4. I have manually shifted into 4wd with transfer case motor off. 4wd works great.
5. I manually put transfer case into 4wd, and bumped motor with power (while not installed) to advance it to 4wd position. Installed transfer case motor. Did not get any 4Hi light on instrument cluster. Shift knob worked to change to 4Lo and back to 4Hi, but no 4Lo or 4 Hi lights on instrument cluster.
6. With original transfer case control module (tccm), I got no lights on instrument cluster at startup. 4wd switch did not produce any clicking noises.
7. With replacement tccm, I DO get lights at startup which then go off. When 4wd switch is turned, clicking sounds, but no flashing lights, and no shift into either 4Hi or 4Lo.
8. Original tccm is part # 1L54-7H417-AD. Junkyard replacement is 1L54-7H417-AE. I am pretty sure these are compatible.
9. I believe the transmission output speed sensor runs through the 4wd system so as to ensure speed is zero for purposes of 4Lo and less than 55(?) for 4Hi. Could a faulty oss be my issue? I do not seem to be having any issues re: speedometer or shifting, so I am reluctant to spend $ and time on replacing that hard to get to sensor when it would seem to be ok given that speedo/tranny working fine.
10. Old truck has almost 280k on it, runs great, and is a beast in 4wd. I got it without 4wd working a couple years ago from original owner, I know it works in 4wd (manually) and love it, and hope someone can help get me to where I can shift into 4wd from the truck!
P.S. With transfer case motor all hooked up to wiring of truck, but not on transfer case, turn of the 4wd switch results in power to the transfer case motor, but it does not rotate, it just kind of just bumps forward and back a small amount. When off the truck and power supplied from a battery, it moves smoothly back and forth.
 


Rock Auto 5% Discount Code: BD8D9A3814E19D Expires July 5th, 2022

DILLARD000

Well-Known Member
Joined
Sep 25, 2020
Messages
580
Reaction score
331
Points
63
Location
Earth
Vehicle Year
2001 Job2
Make / Model
Ford ExST
Engine Size
V6~4.0L~SOHC
Transmission
Automatic
2WD / 4WD
4WD
New forum user with a 2002 XLT Supercab 4x4. Many thanks to the forum users who have posted so much valuable information and advice.

I cannot get 4wd to engage after spending a good amount of time on the forum and under the truck. Here is where I am:

1. All fuses and relays are ok
2. New transfer case motor. New 4wd switch.
3. Replaced transfer case module with junkyard unit
4. I have manually shifted into 4wd with transfer case motor off. 4wd works great.
5. I manually put transfer case into 4wd, and bumped motor with power (while not installed) to advance it to 4wd position. Installed transfer case motor. Did not get any 4Hi light on instrument cluster. Shift knob worked to change to 4Lo and back to 4Hi, but no 4Lo or 4 Hi lights on instrument cluster.
6. With original transfer case control module (tccm), I got no lights on instrument cluster at startup. 4wd switch did not produce any clicking noises.
7. With replacement tccm, I DO get lights at startup which then go off. When 4wd switch is turned, clicking sounds, but no flashing lights, and no shift into either 4Hi or 4Lo.
8. Original tccm is part # 1L54-7H417-AD. Junkyard replacement is 1L54-7H417-AE. I am pretty sure these are compatible.
9. I believe the transmission output speed sensor runs through the 4wd system so as to ensure speed is zero for purposes of 4Lo and less than 55(?) for 4Hi. Could a faulty oss be my issue? I do not seem to be having any issues re: speedometer or shifting, so I am reluctant to spend $ and time on replacing that hard to get to sensor when it would seem to be ok given that speedo/tranny working fine.
10. Old truck has almost 280k on it, runs great, and is a beast in 4wd. I got it without 4wd working a couple years ago from original owner, I know it works in 4wd (manually) and love it, and hope someone can help get me to where I can shift into 4wd from the truck!
P.S. With transfer case motor all hooked up to wiring of truck, but not on transfer case, turn of the 4wd switch results in power to the transfer case motor, but it does not rotate, it just kind of just bumps forward and back a small amount. When off the truck and power supplied from a battery, it moves smoothly back and forth.
Sounds like a weak shift motor, if you see it rotate proper when removed from the TC stem. Bad brushes or bearings. Could take it apart & try to rebuild, or $75 bucks for a new one.
 

RonD

Well-Known Member
Joined
Jun 2, 2012
Messages
21,761
Reaction score
5,156
Points
113
Location
canada
Vehicle Year
1994
Make / Model
Ford
Transmission
Manual
The Shift module use the 5 wires on the transfer case shift motor to "tell it" what position the transfer case motor is in....so what position the transfer case is in
There are no internal sensors in transfer case itself

When you turn on the key the 4x4 module powers up it checks the 5 wires to see what position transfer case shift motor is in, AND if it matches dash 4x4 switch

I assume the 2 4WD lights come on with key on and then go off, a Bulb Test, so bulbs are confirmed working

If you move the switch and transfer case shift motor doesn't move then 4WD lights should flash
If that's not happening then either the switch is not changing resistance/voltage or the 4x4 module is bad

You can test switch resistance between the 2 wires going to 4x4 module(colors seen in diagram below)
3,870 ohms for 2wd,
1,090 ohms for 4wd high
357 ohms for 4wd low

If resistance is not changing when switch is moved then switch is bad, or 1 of the wires is

The 4x4 module sends the switch 5volts
Module gets back approx.
4volts in 2wd
3volts in 4h
2volts in 4l

Yes, its a pull down circuit so resistance and voltage is opposite of what you would think

The 2001-2005 4x4 CM modules were failure prone, just a heads up, for "used"
The 2006 and up are NOT backwards compatible but they were only marginally better than previous 4x4CMs


The 5 wires to shift motor can be tested as well, as the shift motor turns the contacts open and close(short), this "tells" the 4x4CM what position the shift motor/transfer case is in and when to stop moving/sending voltage
53559
 

Attachments

Last edited:

franklin2

Well-Known Member
Joined
Dec 24, 2019
Messages
1,838
Reaction score
679
Points
113
Location
Virginia
Vehicle Year
1984
Make / Model
Bronco II
Transmission
Manual
My old 1986 had a system similar to this. I got it working for about a year with a new motor, and then it would work and then not work. I needed the 4x4 to work. I got fed up with messing with it, so I hot wired the motor with a switch and it worked every time then. I had to make sure I was stopped before I used the switch, but it worked great and was very reliable.
 

DILLARD000

Well-Known Member
Joined
Sep 25, 2020
Messages
580
Reaction score
331
Points
63
Location
Earth
Vehicle Year
2001 Job2
Make / Model
Ford ExST
Engine Size
V6~4.0L~SOHC
Transmission
Automatic
2WD / 4WD
4WD
 
Last edited:

franklin2

Well-Known Member
Joined
Dec 24, 2019
Messages
1,838
Reaction score
679
Points
113
Location
Virginia
Vehicle Year
1984
Make / Model
Bronco II
Transmission
Manual
That's a fine piece of engineering they put in these trucks.....when it works. I don't know what was wrong with the shifter in the floor myself. The autohubs I had always worked though.
 

RonD

Well-Known Member
Joined
Jun 2, 2012
Messages
21,761
Reaction score
5,156
Points
113
Location
canada
Vehicle Year
1994
Make / Model
Ford
Transmission
Manual
That's a fine piece of engineering they put in these trucks.....when it works. I don't know what was wrong with the shifter in the floor myself. The autohubs I had always worked though.
I don't know why we don't just use hand signals any more either, turn signals and brakes lights are just a scam to make bulb makers RICH
What was wrong with hand signals????
I get head lights and park lights, although I think people should just stay off the road after dark, safety first

I get safety glass and seat belts..................some people are stupid enough to drive after its dark

Power windows, power steering, power brakes, power door locks, WTF!!!
Heated seats, cooled seats, double WTF!!!!
 

MikeG

Well-Known Member
Joined
Jul 15, 2020
Messages
1,353
Reaction score
748
Points
113
Location
central Texas
Vehicle Year
1997
Make / Model
B4000
Engine Type
4.0 V6
Transmission
Automatic
2WD / 4WD
2WD
Total Lift
2"
Tire Size
235/75r15
Dana 20 t-case in my '68 always shifted..... and nary a wire to be seen ;)
 

DILLARD000

Well-Known Member
Joined
Sep 25, 2020
Messages
580
Reaction score
331
Points
63
Location
Earth
Vehicle Year
2001 Job2
Make / Model
Ford ExST
Engine Size
V6~4.0L~SOHC
Transmission
Automatic
2WD / 4WD
4WD
I don't know why we don't just use hand signals any more either, turn signals and brakes lights are just a scam to make bulb makers RICH
What was wrong with hand signals????
I get head lights and park lights, although I think people should just stay off the road after dark, safety first

I get safety glass and seat belts..................some people are stupid enough to drive after its dark

Power windows, power steering, power brakes, power door locks, WTF!!!
Heated seats, cooled seats, double WTF!!!!
Bah!!! Humbug!!!
 

MarkDru

New Member
Joined
Dec 31, 2020
Messages
10
Reaction score
2
Points
3
Location
Scituate, MA
Vehicle Year
2002
Make / Model
Supercab 4x4 XL
Transmission
Automatic
Thanks very much for the responses. I have borrowed a friend's multimeter and will be following your advice. I will likely find that the tcm is bad. With original tcm, I got no lights at startup and no clicking of tcm relays. When I purchased the used unit from salvage yard, I plugged it in, had lights at startup and clicking, so I figured it was a good tcm. Well, not so good if it doesn't get me into 4wd, so I guess just because it is clicking does not mean it is "ticking."
I'll be thrilled if I get this going and sure to let you know how it turns out.
 

MarkDru

New Member
Joined
Dec 31, 2020
Messages
10
Reaction score
2
Points
3
Location
Scituate, MA
Vehicle Year
2002
Make / Model
Supercab 4x4 XL
Transmission
Automatic
I really don't understand the chart for ohmeter readings. How are these readings taken using the multimeter? I think I'm in over my head as I have replaced each of the 3 components and I'm really not familiar with electricity or how to use the multimeter. Add to that I am kind of afraid of electricity and causing injury or damage.
 

franklin2

Well-Known Member
Joined
Dec 24, 2019
Messages
1,838
Reaction score
679
Points
113
Location
Virginia
Vehicle Year
1984
Make / Model
Bronco II
Transmission
Manual
You can't take the readings on the chart unless you can make the motor move. You will have to get a battery charger of some sort and move it manually on the bench to get those readings.

Good luck. You already know my feelings on this system. Part of the problems with mine were corroded connections over on the driver's side inner fender. Even fixing that only got it working for a year or so. I don't know about the later trucks,, but the early ones I have had are really bad about throwing road grime/water/salt up onto all those wire connectors laying on the driver's side fender, causing problems. I took a piece of rubber and cut it and attached it to hang over the steering box and that stopped it.
 

RonD

Well-Known Member
Joined
Jun 2, 2012
Messages
21,761
Reaction score
5,156
Points
113
Location
canada
Vehicle Year
1994
Make / Model
Ford
Transmission
Manual
I really don't understand the chart for ohmeter readings. How are these readings taken using the multimeter? I think I'm in over my head as I have replaced each of the 3 components and I'm really not familiar with electricity or how to use the multimeter. Add to that I am kind of afraid of electricity and causing injury or damage.
In this instance an OHM meter is used to tell if a contact is CLOSED(short) or OPEN

Set OHM meter to 200 OHMs or any OHM setting
Touch the two metal tips on the probes together
Should see 0 ohms in the display, that means there is a SHORT in the circuit, which is just the two probes because they are touching, but if one probe was on one wire and the other probe on another wire and you saw 0 ohms then those 2 wires are Connected(a closed contact)
Separate the probes, what do you see?... thats what you should see when a circuit is OPEN, no connection between the probes, or wires you are testing
 

DILLARD000

Well-Known Member
Joined
Sep 25, 2020
Messages
580
Reaction score
331
Points
63
Location
Earth
Vehicle Year
2001 Job2
Make / Model
Ford ExST
Engine Size
V6~4.0L~SOHC
Transmission
Automatic
2WD / 4WD
4WD
As electrical items get replaced on underside (O2Sensors, 4x4ShiftMotor...)
that are exposed to road dirt\debris\salt, I've cut a ~6inch long piece of old bicycle rubber inner tube,
slid that over harness then reconnected plug, slid rubber back over connection, & secured with ZipTies.
Gives those connections a good bit of protection, but still easy enough to remove.
 

MarkDru

New Member
Joined
Dec 31, 2020
Messages
10
Reaction score
2
Points
3
Location
Scituate, MA
Vehicle Year
2002
Make / Model
Supercab 4x4 XL
Transmission
Automatic
Do I understand it correctly that with the transfer case motor hooked up to wiring harness but not bolted on to transfer case, the transfer case motor should (if all things working right) rotate to the corresponding position when 4wd switch in cab is turned? All I get is a little bump of movement in the motor (it's brand new) and a second bump back to where it started.
 

Sponsored Ad


Sponsored Ad

Top