LCAM-01XA
Full Access Member
Alrightie, I'll actually be starting on wiring the new setup in a few, then she goes on a test drive to the gas station and results will be posted here along with wiring diagrams and such 
TC lockup Mod.
- Thread starter Goofyexponent
- Start date
CAUTION THIS IS FOR THE PSD 4R100 ONLY
I will have to investigate the E4OD wiring. The below instruction's are NOT mine, they where taken from someone else. I'll try and find it for credit. I do have it installed on my 99.5 PSD.
NOTICE that there is 3 Purple/Yellow wires going to the 4R100. To make the TC stay in lockup, it's necessary to cancell the OD when switched to TC lockup. This method gives engine braking down to 40 MPH. Using this the RPM's will increase significantly when braking.
I cut and tapped the TC lock wire (purple with yellow tracer on my 99.5 PSD) by tracking the correct wire from the plug located on the drivers side fender well down to a reasonable work location near the floorboards on the drivers side. I split the loom open to see which wire i was wiggling at the top and then cut it. The reason I had to track the wire is there are THREE purple with yellow tracers in my wire harness, and they all three go to the tranny, but to different functions.
There are 4 connectors underneath the brake master cylinder. 3 black ones and one grey one.
You want PIN-6 of the forward most GREY connector. Pinout is as follows:
(4) (3) (2) (1)
(8) (7) (6) (5)
(12)(11)(10)(9)
(16)(15)(14)(13)
I ran a 4-conductor wire from my dash 4x4 switch, under the steering column, and then followed the shift cable to the floorboards and made a small hole for the wire to go under the truck. I then connected one wire (green in my case) to the transmission side of the TC lockup wire that I cut earlier, and another wire (white) to the PCM side of the same cut wire. Soldered and shrinkwrapped. Zip Tie and tape up and your done under the truck.
Back in the cab, I used a third wire from my 4-conductor cable (black) to wire a ground to the dash subframe, and finally the last wire (red) I tied into the "Customer Access" switched hot wire found just above the OBD-II port under the left side of the dash.
I added this below.
Using a DPDT switch, one side is connected to a RED and a GREEN LED's for indication.
I will have to investigate the E4OD wiring. The below instruction's are NOT mine, they where taken from someone else. I'll try and find it for credit. I do have it installed on my 99.5 PSD.
NOTICE that there is 3 Purple/Yellow wires going to the 4R100. To make the TC stay in lockup, it's necessary to cancell the OD when switched to TC lockup. This method gives engine braking down to 40 MPH. Using this the RPM's will increase significantly when braking.
I cut and tapped the TC lock wire (purple with yellow tracer on my 99.5 PSD) by tracking the correct wire from the plug located on the drivers side fender well down to a reasonable work location near the floorboards on the drivers side. I split the loom open to see which wire i was wiggling at the top and then cut it. The reason I had to track the wire is there are THREE purple with yellow tracers in my wire harness, and they all three go to the tranny, but to different functions.
There are 4 connectors underneath the brake master cylinder. 3 black ones and one grey one.
You want PIN-6 of the forward most GREY connector. Pinout is as follows:
(4) (3) (2) (1)
(8) (7) (6) (5)
(12)(11)(10)(9)
(16)(15)(14)(13)
I ran a 4-conductor wire from my dash 4x4 switch, under the steering column, and then followed the shift cable to the floorboards and made a small hole for the wire to go under the truck. I then connected one wire (green in my case) to the transmission side of the TC lockup wire that I cut earlier, and another wire (white) to the PCM side of the same cut wire. Soldered and shrinkwrapped. Zip Tie and tape up and your done under the truck.
Back in the cab, I used a third wire from my 4-conductor cable (black) to wire a ground to the dash subframe, and finally the last wire (red) I tied into the "Customer Access" switched hot wire found just above the OBD-II port under the left side of the dash.
I added this below.
Using a DPDT switch, one side is connected to a RED and a GREEN LED's for indication.
Last edited:
Goofyexponent
Mentally Unstable..
I am sooo sorry this is taking FOREVER to do. I HAVE to get off my rearend and take pictures of everything and post them. Those diagrams are a PERFECT explanation as to what I did with mine. I will get off my butt FIRST thing tomorrow and git'r done! I PROMISE!
LCAM-01XA
Full Access Member
Well I did it, and it works. Additionally to 1st and 2nd gear, SS1 is active in park, reverse, and neutral, so which allows the TC to be locked only in 3rd and 4th. I'll get into details a bit later on as right now I got a driveshaft that needs the U-joints replaced...
But, with respect to what OldBull8 posted last about the 4R100 transmission - the E4OD has only one purple wire with yellow tracer, there's only one more purple wire in the harness but it has an orange tracer and it's used to ground SS2.
But, with respect to what OldBull8 posted last about the 4R100 transmission - the E4OD has only one purple wire with yellow tracer, there's only one more purple wire in the harness but it has an orange tracer and it's used to ground SS2.
trackspeeder
Stone crusher.
The extra wires on the 4R100 are for the TSS and OSS. The PCM uses those in addition to the VSS to determine converter lock up.
For the E4OD just do what you did.
tractorman86
Registered User
I
So if I send you some relay pigtails and a little cash you will make a harness with installation instructions for me right
So if I send you some relay pigtails and a little cash you will make a harness with installation instructions for me right
LCAM-01XA
Full Access Member
Oh, good to know thenThe extra wires on the 4R100 are for the TSS and OSS. The PCM uses those in addition to the VSS to determine converter lock up.
For the E4OD just do what you did.
In all honesty I don't think it would be easy to pre-make a harness for this - for one thing everyone likes their switch at a different location, for instance mine is on the shifter but that's cause I welded up a little bracket for it there, while most folks seem to like them on the dash somewhere. Then there's the matter where you want the LEDs, and so on... However when we're done with this subject here you will have detailed instructions and diagrams to make your own harness and run it any which way you please, along with at least two options as far as manual switch setup goes (on/off or on/off/auto)... I'm working on this already, so hold on for a bit moreSo if I send you some relay pigtails and a little cash you will make a harness with installation instructions for me right
tractorman86
Registered User
Man... jk I was kinda giving you a hard time, I was only a little serious
LCAM-01XA
Full Access Member
OK, one diagram complete, this is for the auto-lock setup where you can flip the switch between full PCM control of the lockup (factory settings and all) and manually locked converter.
When the "manual lock" mode is selected the converter will stay locked all the time in 3rd and 4th gear regardless of whether brakes are applied or not, until you either flip the switch back to "auto" mode or slow down enough to where the transmission drops out of 3rd gear. Converter will NOT lock in 1st or 2nd gear.
When you switch to "auto" mode the TCC circuit effectively reverts to factory-designed operation as the PCM gets linked to the TCC directly, the protective relay is bypassed so even tho it still clicks on and off as the transmission shifts between 2nd and 3rd gear it has no bearing on the TCC lockup.
Wiring code:
- purple wire with yellow tracer - responsible for TCC operation, this is the one inside the transmission harness that you cut and extend both ends and feed them into the cab, the end from the TCC goes to the relay and the end from the PCM goes to the switch.
- orange wire with yellow tracer - responsible for SS1 operation, lives in the transmission harness, however this one you do NOT cut, just a splice another wire into it and feed the new wire in the cab to the relay.
- red wire - you need to add this one, use one of these "Add-A-Circuit" fuse holders that can be found at about any decent parts store, they're good for up to 10 amps on the aux circuit but you won't be pulling even half that.
- black wire - this is the ground that will lock your converter when you select "manual lock" mode, so make sure it's grounded real good.
- gray wires - those are optional, they are for the three LEDs: red LED is on when you're in "manual lock" mode, green LED is on when you're running into "auto" mode, and yellow LED comes on to warn you the converter will not lock cause the transmission is not in 3rd or 4th gear yet - basically you wait for the yellow to go off, and then switch between green ("auto" mode) and red ("manual lock" mode).
***Please note that it is possible to wire the red LED so it follows the actual converter lockup in both "manual lock" and "auto" modes, however this will result in the red LED coming on whenever the PCM locks the converter so you'll often have both the red and the green LEDs glowing at you, and if some of the claims I've seen posted on FTE are correct and the PCM can and will actually lock the converter in 2nd gear you may end up with an entire traffic light on your dash - green cause you're running in "auto" mode, yellow cause you're still in 2nd gear, and red cause the PCM did in fact lock the converter As you can imagine, I already have that wiring diagram drawn up 
When the "manual lock" mode is selected the converter will stay locked all the time in 3rd and 4th gear regardless of whether brakes are applied or not, until you either flip the switch back to "auto" mode or slow down enough to where the transmission drops out of 3rd gear. Converter will NOT lock in 1st or 2nd gear.
When you switch to "auto" mode the TCC circuit effectively reverts to factory-designed operation as the PCM gets linked to the TCC directly, the protective relay is bypassed so even tho it still clicks on and off as the transmission shifts between 2nd and 3rd gear it has no bearing on the TCC lockup.
Wiring code:
- purple wire with yellow tracer - responsible for TCC operation, this is the one inside the transmission harness that you cut and extend both ends and feed them into the cab, the end from the TCC goes to the relay and the end from the PCM goes to the switch.
- orange wire with yellow tracer - responsible for SS1 operation, lives in the transmission harness, however this one you do NOT cut, just a splice another wire into it and feed the new wire in the cab to the relay.
- red wire - you need to add this one, use one of these "Add-A-Circuit" fuse holders that can be found at about any decent parts store, they're good for up to 10 amps on the aux circuit but you won't be pulling even half that.
- black wire - this is the ground that will lock your converter when you select "manual lock" mode, so make sure it's grounded real good.
- gray wires - those are optional, they are for the three LEDs: red LED is on when you're in "manual lock" mode, green LED is on when you're running into "auto" mode, and yellow LED comes on to warn you the converter will not lock cause the transmission is not in 3rd or 4th gear yet - basically you wait for the yellow to go off, and then switch between green ("auto" mode) and red ("manual lock" mode).
***Please note that it is possible to wire the red LED so it follows the actual converter lockup in both "manual lock" and "auto" modes, however this will result in the red LED coming on whenever the PCM locks the converter so you'll often have both the red and the green LEDs glowing at you, and if some of the claims I've seen posted on FTE are correct and the PCM can and will actually lock the converter in 2nd gear you may end up with an entire traffic light on your dash - green cause you're running in "auto" mode, yellow cause you're still in 2nd gear, and red cause the PCM did in fact lock the converter
As you can imagine, I already have that wiring diagram drawn up
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LCAM-01XA
Full Access Member
I know it was a joke, but it was also a perfectly legit questionMan... jk I was kinda giving you a hard time, I was only a little serious
Don't know if anyone read my post about loseing the trailer brakes on a 9% down grade in the Yukon. But thank God for the TC lockup. 85 MPH at times, smoking front brakes, red hot rotors, 4000 RPM at times. Clean Fruit of the Looms.
Very nice write up. Excellent circuit pix.
Tech Article please.
Tech Article please.
LCAM-01XA
Full Access Member
Don't recall seeing that post, but man that must have been a hairy experience! Was that with the PSD? Cause if it was one of your IDIs with those 4000 rpms you're getting into dyoung14 territory, and I'm quite certain that deep in dyoung14 territory there be fire-breathing dragons! lol
LCAM-01XA
Full Access Member
Hold it, ain't done yet! Got at least one more coming up, probably two tho...
LCAM What do you use to draw those circuits? Really neet.
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