E38 4.8 conversion issues
Thread Starter
Launching!
Joined: Mar 2005
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From: Elgin,IL
E38 4.8 conversion issues I have an 08' 4.8/4L80 that I installed in my 66' Chevelle and thought I had a good possibility of starting her today with no luck. I am not getting any data communication to my Dash Hawk nor is the fuel pump turning on at key on. I have been over my temporary connections a dozen times with no luck in getting anything working.
In looking at the pinouts I notice that plug X100 shows a serial data enable wire as well as an accessory wakeup serial data wire. Could either of these be the issue as neither is hooked up to anything? Also, I do not have the pedal in the car right now as I was not concerned about driving the car as I am just confirming wiring right now to get the car running. Could this be part of the problem?
I did the harness work on my 72' without any issues and thought this conversion would go just as smooth. This set up has the E38 PCM. Thanks in advance for any light you guys might be able to shed on my issues.
In looking at the pinouts I notice that plug X100 shows a serial data enable wire as well as an accessory wakeup serial data wire. Could either of these be the issue as neither is hooked up to anything? Also, I do not have the pedal in the car right now as I was not concerned about driving the car as I am just confirming wiring right now to get the car running. Could this be part of the problem?
I did the harness work on my 72' without any issues and thought this conversion would go just as smooth. This set up has the E38 PCM. Thanks in advance for any light you guys might be able to shed on my issues.
Do you have the can bus wired from the ECM to the TCM to the DLC Correctly?
Jon
PSI
Jon
PSI
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Thread Starter
Launching!
Joined: Mar 2005
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From: Elgin,IL
Only thing I have hooked up to the Dash Hawk right now is wire 28 which is he high speed serial bus wire from pin 28 of the X1 plug. With the harnes being hacked due to some hillrods pulling it from the van I have two other tan, tan/black wires in the harness that I think are going to the tcm. These two wires are not hooked to anything at this time.
Obviously I will need the dlc to work for tuning purposes etc but at key on I dont even get the green/white wire from pin 50 on X1 plug to turn on the pump for priming. This was the reason for the question about the pedal as the wires are not hooked to anything at this time. I didnt know if the pcm needed to see the pedal for the prime wire to go hot.
DBW is new to me and as I said some stuff within the harness was hacked up pretty good.
Obviously I will need the dlc to work for tuning purposes etc but at key on I dont even get the green/white wire from pin 50 on X1 plug to turn on the pump for priming. This was the reason for the question about the pedal as the wires are not hooked to anything at this time. I didnt know if the pcm needed to see the pedal for the prime wire to go hot.
DBW is new to me and as I said some stuff within the harness was hacked up pretty good.
Pedal does not need to be hooked up to get the F/P to prime. Im sure you probably know this, but remember the fuel pump wire is providing power, not ground.
Jon
PSI
Jon
PSI
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Thread Starter
Launching!
Joined: Mar 2005
Posts: 216
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From: Elgin,IL
Thanks. I must have some other harness issues then. I am running the hot lead from the PCM to a relay that powers the fuel pump. As I have no prime from the PCM and nothing on the Dash Hawk I think I may need to dig into the harnes further to see if there is more damage that I may have overlooked.
I did confirm that my painless 7 ckt set up has constant power on the leads that should and the ignition hot on the other wires. PCM red/blk and red/wht have constant power and the pinks all have the ignition hot to them. Every ground in the harness has an excelent ground to it so other damage is my only other idea.
Heading out the garage now with a few barley pops to see what I can come up with. I will have an update with what I find.
I did confirm that my painless 7 ckt set up has constant power on the leads that should and the ignition hot on the other wires. PCM red/blk and red/wht have constant power and the pinks all have the ignition hot to them. Every ground in the harness has an excelent ground to it so other damage is my only other idea.
Heading out the garage now with a few barley pops to see what I can come up with. I will have an update with what I find.
Thread Starter
Launching!
Joined: Mar 2005
Posts: 216
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From: Elgin,IL
Well we are getting somewhere. I got the pump to prime but still have nothing on the Dash Hawk which means I will have nothing on HPT. I can get the Hawk to light up as I have power and ground to it but it will not read the PCM.
It seems the issue with the pump is related to the X1 plug on the harness which does not lock properly to the PCM. Back to the hill rods that removed the combo from the wrecked van must have been wrecked themselves. Either that or it was the week the local batch of meth came in. I wouldnt trust the guys that removed the engine/trans to change my oil. Every time I turn around it it something else.
The combo that is in my other car was removed just as I would remove it for a paying customer, with care! Not a wire was damaged or a scuff even put on the engine or trans when pulling them. This time around I think my 11 year old son and a couple of his buddies could have done a better job with the removal.
At this point the engine will not fire and after priming the pump a half a dozen times I have no fuel on the plugs. I was not able to confirm spark as at this hour I am solo in my garage. As far as I can tell all wiring is correct and I have voltage to all pink wires at key on.
We have done nothing to this point with VATS so I dont know if this is the problem or not. Either way I need to figure out why the PCM will not communicate with the Dash Hawk. I am going to install the PCM in my truck which is also running the E38 PCM to see if it will at least start. If it does I will know it is wiring related and not PCM related.
It seems the issue with the pump is related to the X1 plug on the harness which does not lock properly to the PCM. Back to the hill rods that removed the combo from the wrecked van must have been wrecked themselves. Either that or it was the week the local batch of meth came in. I wouldnt trust the guys that removed the engine/trans to change my oil. Every time I turn around it it something else.
The combo that is in my other car was removed just as I would remove it for a paying customer, with care! Not a wire was damaged or a scuff even put on the engine or trans when pulling them. This time around I think my 11 year old son and a couple of his buddies could have done a better job with the removal.
At this point the engine will not fire and after priming the pump a half a dozen times I have no fuel on the plugs. I was not able to confirm spark as at this hour I am solo in my garage. As far as I can tell all wiring is correct and I have voltage to all pink wires at key on.
We have done nothing to this point with VATS so I dont know if this is the problem or not. Either way I need to figure out why the PCM will not communicate with the Dash Hawk. I am going to install the PCM in my truck which is also running the E38 PCM to see if it will at least start. If it does I will know it is wiring related and not PCM related.
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I'm interested to hear how this works out. I haven't done a gen IV swap yet and it sounds like there are some different quirks to each one that pop up. Is there something that has to be done if you're not running the other modules in the GM LAN? Like connect the terminal wires so they loop instead of being open ended?
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Verdad Gallardo VEGASROBBI on here and the efilive forum has some good insight into getting the e38 to work on swaps if you haven't seen these posts yet:
https://ls1tech.com/forums/conversio...e-e38-pcm.html
https://ls1tech.com/forums/conversio...lp-needed.html
I belive bsharpe has his working in his chevelle as well...maybe he can chime in here
https://ls1tech.com/forums/conversio...e-e38-pcm.html
https://ls1tech.com/forums/conversio...lp-needed.html
I belive bsharpe has his working in his chevelle as well...maybe he can chime in here
Thread Starter
Launching!
Joined: Mar 2005
Posts: 216
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From: Elgin,IL
Was nosing around the tuning section and found a posting for a bench test harness for my E38/T42 combo. I think I may have found out why I cannot read anything on the Dash Hawk. I have my wires on pins 2,4,5 & 16. This bench test drawing shows them on 4,5,6,14 & 16. If this is correct no wonder I cant read anything on the DH. Car still will not start though. Since VATS is still enabled wouldnt the car at least start and die or does it have to be removed to start at all?
Thread Starter
Launching!
Joined: Mar 2005
Posts: 216
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From: Elgin,IL
Got the DH working. I have it set to read RPM, IAT, STFT and trans gear. During cranking the RPM will display and as the temp went up the garage the IAT went up but it appears that the trans will read nothing but second gear even when in park. Probably just some more messed up wires in the harness.
The engine will not start at this time and I have no fuel on the plugs so I still have some work to do. I was solo in the garage so I cannot confirm spark at this time.
The engine will not start at this time and I have no fuel on the plugs so I still have some work to do. I was solo in the garage so I cannot confirm spark at this time.
This should be the pinout for the DLC
1 Low Speed GMLAN Serial Data
2-3 Not Used
4 Ground
5 Ground
6 High Speed GMLAN Serial Data Bus (+)
7-13 Not Used
14 High Speed GMLAN Serial Data Bus (-)
15 Not Used
16 Battery Positive Voltage
what is your starting circuit like?
1 Low Speed GMLAN Serial Data
2-3 Not Used
4 Ground
5 Ground
6 High Speed GMLAN Serial Data Bus (+)
7-13 Not Used
14 High Speed GMLAN Serial Data Bus (-)
15 Not Used
16 Battery Positive Voltage
what is your starting circuit like?
Thread Starter
Launching!
Joined: Mar 2005
Posts: 216
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From: Elgin,IL
The below other than pin #1 is how the DLC is wired now and it seems to be working.
As far as the starting circuit goes I have the factory purple wire from the car on the starter and thats it. I am not using the truck harness wires all all for the starting circuit. I know there is a purple wire in the harness but do not have it hooked to anything. There is another wire that I belive is yellow/blk that goes to the factory starter relay also. This wire is not hooked to anything either. Should these be integrated in somehow?
As far as the starting circuit goes I have the factory purple wire from the car on the starter and thats it. I am not using the truck harness wires all all for the starting circuit. I know there is a purple wire in the harness but do not have it hooked to anything. There is another wire that I belive is yellow/blk that goes to the factory starter relay also. This wire is not hooked to anything either. Should these be integrated in somehow?
I don't think you need to use those wires from the truck harness unless you're using the bcm and running the ignition switch through it (the ignition request goes to the bcm and the bcm signals the ecm to trigger the starter relay), but I could be wrong. If you're able to communicate with the ecm, you should be able to change the vats/starting requirements which I think would do the trick.
If that doesn't work I wonder if it has anything to do with the computer thinking the trans is in 2nd instead of park/neutral.
If that doesn't work I wonder if it has anything to do with the computer thinking the trans is in 2nd instead of park/neutral.
Thread Starter
Launching!
Joined: Mar 2005
Posts: 216
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From: Elgin,IL
I didnt think they would be needed for the same reason and didnt need them on my 72'. I also didnt know if with the E38/T42 they might be needed for some reason. You could also be onto something with the the DH showing 2nd gear on the display. I will figure that issue out first and then see if I can get the car started.
Thread Starter
Launching!
Joined: Mar 2005
Posts: 216
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From: Elgin,IL
You wanted an update. This thing is still giving me fits!
I think the PCM is VATS locked and I cant do anything with it via HPT. I have come to this conclusion by the way of swapping out a known good PCM and TCM into the Chevelle for test purposes. Even with the known good items the vehicle still will not start though. I can communicate with and read and write a tune but something is still up and I think it might be in the harness.
Lucky for me I have an 08' Sierra so I threw those parts on the Chevelle to see if I could connect and read/re write the PCM and TCM and possibly start it. I was able to do the read/write without a hitch. When I put the parts from the Chevelle that I cannot read into my truck I get a message on the dash that the theft deterent system has been activated. I cannot read either the PCM or TCM when installed into my truck. At this point I dont think I can unlock the PCM with HPT but I could be wrong.
I will admit that I am a newbie with HPT. I was able to play with the TM a bit on the Sierra TM which definetly makes for some more fun when you mash the go pedal. Just for clarification I first disabled VATS on my truck PCM before trying to start the car.
I think the PCM is VATS locked and I cant do anything with it via HPT. I have come to this conclusion by the way of swapping out a known good PCM and TCM into the Chevelle for test purposes. Even with the known good items the vehicle still will not start though. I can communicate with and read and write a tune but something is still up and I think it might be in the harness.
Lucky for me I have an 08' Sierra so I threw those parts on the Chevelle to see if I could connect and read/re write the PCM and TCM and possibly start it. I was able to do the read/write without a hitch. When I put the parts from the Chevelle that I cannot read into my truck I get a message on the dash that the theft deterent system has been activated. I cannot read either the PCM or TCM when installed into my truck. At this point I dont think I can unlock the PCM with HPT but I could be wrong.
I will admit that I am a newbie with HPT. I was able to play with the TM a bit on the Sierra TM which definetly makes for some more fun when you mash the go pedal. Just for clarification I first disabled VATS on my truck PCM before trying to start the car.
Thread Starter
Launching!
Joined: Mar 2005
Posts: 216
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From: Elgin,IL
Forgot to mention this in the last post. There is a wire that runs from the X1 PCM plug to the TCM. It is on pin 18 and is the accessory wake up serial data. This was cut in the haness when I got it and I am assuming that it returned back to the BCM in the facory configuration. Am I correct in my thinking?