PCM fun....

[Docfranco]

Hi All
I am nearing startup on my 6.5 td swap into my Scout. the 6.5 TD is a 98 with a 4l80E. Westers has done a reflash for a 96 so i will not have to run a body control module (i think that is what he called it) after playing for a few days i have concluded the pcm must not be working. i was not getting any glow cycle or lift pump or injection pump action. no DTC's on my acton cp9135 scanner which should read codes. Lyndon @ westers agreed that with no codes only "link error" it must be a bad PMC. I have the ppl sieral data line with power and two grounds going to the data link connector as lyndon suggested. i have wired the lift pump to the ignition to see if i can get any fuel to the injectors and nothing. It turns over fine but not much else. i get fuel to the top of the filter and out the brass t valve though.the new pcm should be here this week, is there anything that comes to mind i may be missing? i am open to most anything to look at..... thanks

[Cowracer]

doc,

I don't think anyone will bite on this. We ain't ignoring you, its just that there are SO many variables in this problem that there would be no way to even begin helping you. I can't think of anyone who would feel qualified to even hazard a guess.

When you start brain surgery on a OBDII truck, you are kinda out there alone. Replacing the PCM is a first start, but I wouldnt hold my breath on it fixing the problem.

GMCTD gave me some info on the signals being passed between the ECM and PMD/FSD. This thread has the info. You might want to make sure that the ECM and FSD are at least talking to each other. I hope it helps

clicka dis link, right here! (http://forum.thedieselpage.com/cgi-bin/ultimatebb.cgi?ubb=get_topic;f=1;t=008088)

Best of luck to ya!
Tim

[gmctd]

How much of the wiring did you transfer from the donor truck?

[Docfranco]

i bought a new 98 harness from the stealer (ouch)

[Docfranco]

i bought a new 98 engine/trans harness from the stealer (ouch)and then picked up a under dash harness to hook up the data link & ignition wiring

[gmctd]

You have a complete harness, incl the convenience center\fuse block?

[Docfranco]

yes, complete. i have removed extras such as AC, radio controls ect. I have gotten the complete pinout discriptions to hook-up the ignition & data link connectors. I have done some continuity checks to make sure the wires indicated on the pinout go where i think they should be...tach, charge indicator ect...

[gmctd]

Ok - power to the fuseblock, key on, applies ignition to 4 points on the PCM, which requires two specific grounds.

Fuseblock also supplys +12v to ESO, PMD, FS, Glow Controller, Lift Pump.

The Fusible Linked Battery Block supplys fusible linked power to Glow, Alt.

All harness grounds tie to chassis, to engine, to Battery.

The APP has it's own harness to the PCM-to-instrument cluster harness, with Water-in-Fuel and Low Coolant modules.

PCM checks at power-on for most sensors - Boost, Baro, ECT, IAT, CPS, OS - , also various warning lamps - Service Engine Soon, Service Throttle Soon, Check Gages - with resultant DTC at error.

If power is applied, all's well, PCM should blink 12 three times on an OBDII code scanner - 39.95 at Harbor Freight.

[Docfranco]

on the 98 engine harness there are 3 wires with crimped rings near the passenger side firewall, black, black/white, tan/white. I know the black and the blk/white are grounds and go to the engine block. Is the tan/white also a ground? I should get the relpacement pcm in a day or so. Which 4 pins on the pcm should have 12 volts? thanks for your help

[diesel65]

Yes,
Tan/wht is a ground connection

On the blue 32 pin connector at PCM:

C11....pink wire....Ignition
C12....pink wire....Ignition
C13....orange wire....Battery

D13....orange wire....Battery

D6.....blk/wht wire...Ground
D7.....tan/wht wire...Ground

[ 03-15-2005, 04:21 PM: Message edited by: diesel65 ]

[gmctd]

Tan\White and Black\White are the two main PCM grounds.

ECM B fuse is always hot to PCM

INJ 1,2 fuse is hot from IGN switch

[Docfranco]

ok, got the new pcm and plugged it in. I now hear the glow relay clicking and the terminal that goes to the plugs is getting power. I still am not getting the glow plug wait light to light. i think the dark blue wire on the bulkhead pinout should go to the light and then ground. I will check the IP thursday and see if it will start. The scanner is now linking up and gave me a p1656 code, wastegate solenoid. i am going with the turbomaster, so i dont have the solinoids on.

[gmctd]

Excellent - Red is +12v Power and Lighting, Pink is IGN, Orange is Accessory and Lighting in that bulkhead connector.

[Docfranco]

Got it to fire up today....!!!!! yeeee hawwww....idle's real nice....but....i do not have any throttle response. it is fly by wire so i am now going to look at the pcm for vlotages to the pedal and start tracing....but i was stoked to hear it come to life.... :eek: :eek: :eek: :eek:

[Cowracer]

ITS ALIVE!!!

Maybe your username should be DOCFRANKEN? Kudos to going where few have gone before and living to tell the tale! It's all downhill from here

Tim

[Docfranco]

After talking to Lyndon @ westers about the wiring, i found that i had the ebcm connector plugged into the acelerator pedal, Doh!!! I changed that and it starts runs and sounds great thru-out the throttle range, the 4 inch pipe sounds great, cant wait to finish the front end & hi steer so i can drive it.
WHEW.....

[CareyWeber]

GREAT JOB!!!

Doc

[Marty Lau]

Congrats!!! I'm glad you got the Scout going and should be a fun outfit with a 6.5 TD. Why did you go the Elctronic route as far as IP why not go with the 92/93 version with the manual pump, I would have thunk it would have been a little less work? :confused:

[Docfranco]

I got a good deal on the 98, and i was not "enlightened" regarding the E-IP's at that time. I may have gone the 92-93 route if i already know what i do now. But i think and am hoping the 4L80E will work better with a OEM harness and setup. time will tell me how much i REALLY saved. If this injection pump starts giving me problems, i may look at the manual pump, then i have to control the 4L80 ect....
but for now i will go with it and mount my spare FSD anf imine starts stalling then just plug it in.