98 Yukon 411 pcm swap 2 bar OS will not shift second gear

[JANNETTYRACING]

Good Morning all,

I have a mess I am trying to clean up and have been successful up to this point

As stated in the title this is a 98 Yukon XL 350 whipple supercharged 4l60E with a 411 PCM swap and 2 bar operating system.

Everything is new, trans valve body solenoids and now another PCM and the same problem persists.

I can see the command for the 1-2 shift but the trans will not shift to second gear it will wind out until it commands the 2-3 shift then shifts from 1-3 and shifts to 4th ok as well.

If I cut the wire for the 1-2 solenoid the trans shifts to 2nd gear no problem

So I am hoping someone might have an Idea to share, I don't know if it is something in the calibration or if the wire is in the wrong port that is grounded all the time.

We have verified the wiring with the guy who supplied the 411 pcm swap in the first place Light green wire in Pin 48 in the Red connector

[Ben Charles]

Wire is in the wrong port!!! Seen this before... exact same problem

[JANNETTYRACING]

Thanks Ben, Any Hint on what port is the correct port for the 1-2 shift solenoid?

[JANNETTYRACING]

Follow up question, When you install a 2 bar custom OS can it change what the Ports do?

I have checked several computer pinouts and they all say 48 in the Red connector is for Solenoid A.

[ScarabEpic22]

No, you cannot change the pinouts with a custom OS. The only way I'm aware of is to change the base calibration (i.e. Camaro to a truck).

[JANNETTYRACING]

The base file is a 2001 G3500 Express van 5.7

[Mrich0908]

Did you figure it out? If not I live down the street from you and have a working licensed 0411 ecu with a sbc350 swap you can try. I shop there pretty often also . You know who I am by face im sure.
Mark

[JANNETTYRACING]

Did you figure it out? If not I live down the street from you and have a working licensed 0411 ecu with a sbc350 swap you can try. I shop there pretty often also . You know who I am by face im sure.
Mark

Hello Mark,
No we did not any help is appreciated.

[Mrich0908]

I was just there ill stop by lol. Ask Al I was just talking to him about catch cans. Ill PM you.

[ScarabEpic22]

Have you compared your wiring to that of an 01 Express van like Ben said?

So it winds out until it hits the 2->3 shift threshold then shifts 1->3? You're hitting 62mph in 1st gear? Have you put the RPM and then separately the MPH shift points super low to see if it just cant mechanically make the shift? I.E. set MPH low so it shifts at the WOT RPM and then try setting RPM low so it shifts at WOT MPH.

Can you hold 1st gear using the Scanner controls, then force it to shift 1->2?

[JANNETTYRACING]

Have you compared your wiring to that of an 01 Express van like Ben said?

So it winds out until it hits the 2->3 shift threshold then shifts 1->3? You're hitting 62mph in 1st gear? Have you put the RPM and then separately the MPH shift points super low to see if it just cant mechanically make the shift? I.E. set MPH low so it shifts at the WOT RPM and then try setting RPM low so it shifts at WOT MPH.

Can you hold 1st gear using the Scanner controls, then force it to shift 1->2?

I can see the shift happen on the scanner so the software is doing it's thing.

What is not happening as I explained above it the ground is not being taken away from pin 48 or the Green wire for the 1-2 solenoid, if I cut the wire it shifts.

I can move the shift points around and see the change in the scanner the 1-2 shift solenoid changes from on to off right where I command it to so this is not a programming issue.

Seems to be an operating system or hardware issue with in the PCM.

I have tried a second PCM with the same program and the same results.

My gut tells me something is getting screwed up by the 2 bar operating system.

I have another PCM here I just bought for a 1/2 ton van with 4l60 trans that I may try when I get a chance but I don't expect a different result.

PCMPOWERTUNES provided this computer, swap package, and has tried to help to no avail.

Ted.

[Mrich0908]

Have you compared your wiring to that of an 01 Express van like Ben said?

So it winds out until it hits the 2->3 shift threshold then shifts 1->3? You're hitting 62mph in 1st gear? Have you put the RPM and then separately the MPH shift points super low to see if it just cant mechanically make the shift? I.E. set MPH low so it shifts at the WOT RPM and then try setting RPM low so it shifts at WOT MPH.

Can you hold 1st gear using the Scanner controls, then force it to shift 1->2?

I went down there today looked at his swap file and trans . Its the same one I used for the same model truck.
Mine works fine. The pin is in the proper place. For reference 7 links down on this page is the 99-02 ecm. Same pin out he has.
http://www.lt1swap.com/2000harness.htm or http://www.lt1swap.com/1999-02pcmpinouts.pdf

I can see the shift happen on the scanner so the software is doing it's thing.

What is not happening as I explained above it the ground is not being taken away from pin 48 or the Green wire for the 1-2 solenoid, if I cut the wire it shifts.

I can move the shift points around and see the change in the scanner the 1-2 shift solenoid changes from on to off right where I command it to so this is not a programming issue.

Seems to be an operating system or hardware issue with in the PCM.

I have tried a second PCM with the same program and the same results.

My gut tells me something is getting screwed up by the 2 bar operating system.

I have another PCM here I just bought for a 1/2 ton van with 4l60 trans that I may try when I get a chance but I don't expect a different result.

PCMPOWERTUNES provided this computer, swap package, and has tried to help to no avail.

Ted.

Ted did you guys take a multi meter and make sure there are not breaks in the wire. Swapped light greens (there are more than 1) or did it get Pinched during install or the round connector get pinched when installed in the 4l60e .
Did you go through the harness and make sure the tack is present . Circuit 1020 has 12v ignition (12v side to the solenoid) the ecm is seeing vss , tps signals (im just tossing out what comes to mind).
Does pin # blue 79 2-3 shift solenoid control have anything to do with the problem?
here is a great post also that may help or not. You say the ecm is sending its signal . It could be the transmission its self.
Lastly I would run you own wire from pin 48 to circuit 1222( 1-2 shift solenoid ground inside the 4l60e round connector) this way you know its making it to the connector.
He may have to go back through his work to make sure he repined his ecu properly.

Common failures on 4L60E, symptom < cause > any possible repair:

1. Slow, slipping or no reverse: “lo-reverse” clutches are worn out, fluid leak in the reverse apply circuit, or broken sunshell. It is possible to remedy a fluid problem by removing the checkball from its cage in the case in the rear of the trans may help (must remove valvebody), or adding a high-viscosity additive such as Lucas Transmission additive or other seal restorer product. May also have worn boost valve (can replace in the pan).

2. 1-2 shift does not happen at WOT until you let off the gas: Best case: try replacing the TPS. Middle case: leak in the 2nd gear apply circuit (servo assembly or 1-2 accumulator). Doublecheck by using the pressure gauge and watch for a big drop when the PCM commands 2nd gear. Worst case: poor line pressure rise (see below).

3. 1-2 Shift shudder at WOT; delayed or abnormal 1-2 shift; There's a problem ONLY on the 1-2 shift: 1-2 accumulator piston cracked or stuck cocked in the bore. Check the yellow spring inside the accum housing for breakage. Also, if the accumulator housing walls are scored, the housing must be replaced. Easy fix in the pan.

4. 1-2 shift is delayed and harsh, may not shift into OD: Check TPS for smooth and linear electrical response over the entire range of motion. If not, replace.

5. Trans does not upshift out of first, speedometer reads zero at all times: VSS failure. Easy fix on rear of transmission, but xmember must come out to access VSS.

6. No 3rd or 4th gear: “3-4” clutches are worn out. R&R. The car is safe to drive (in 2) until you can get it fixed.

7. Sudden grinding noise with no prior warning primarily in 2nd gear, behavior in reverse may be abnormal; sunshell is fractured. R&R. Try not to run or drive the car or further damage could result.

8. 1st and 3rd only, no 2,4 or R; sunshell is fractured or splines are sheared off. R&R. Try not to run or drive the car or further damage could result.

9. No 2nd or 4th gear. 2-4 band is slipping. Servo seals may be damaged (can be fixed without removing trans. Otherwise, 2-4 band is worn out. R&R.

10. Trans shifts into gear harshly, car feels sluggish off the line, No 1st, 4th or TCC lockup available, Manual 2nd, 3rd and Reverse are only available gears, CEL is on: Transmision is either in limp-home mode or has lost electrical power. If there are lots of error codes in the PCM, check the underhood fuse that powers the transmission, and if it pops again, look for a short in that circuit like an O2 sensor harness touching exhaust. Otherwise, check PCM codes for a particular fault in the transmission causing the PCM to put it in limp-home mode.

11. No 1st or 4th available; trans shifts 2nd to 3rd by itself in D or OD and locks the converter : ShiftA solenoid failed. Easy fix in the pan. Or a wiring problem from PCM to trans.. or PCM.

12. Car goes into gear but feels very sluggish like the brakes are dragging, but it will roll easily (starts out in 4th gear), you manually shift to 2 to get it moving, once it's moving you put it back in OD and the car shifts 3rd to 4th on its own and locks the converter at the appropriate time: ShiftB solenoid failed: Easy fix in the pan. Or a wiring problem from PCM to trans.. or PCM.

13. No TCC lockup: Brake pedal switches improperly adjusted (always on), TCC solenoid failed (easy fix in the pan), TCC clutch worn out (must remove trans and replace TC).

14. TCC always locked: TCC apply solenoid circuit shorted to ground, TCC solenoid blockage (easy fix in pan), or TC broken (must remove trans and replace TC).

15. Horrible noise in 4th and feels like the brakes are on: overrun clutches are applying due to a cracked or leaking forward piston. Overrun clutches will be worn out after 30 seconds of this behavior. Car can be safely driven in D. R&R.

16. Soft shifting, gradual performance degradation: Poor line pressure rise due to leaking boost valve, clogged EPC filter screen, failing EPC solenoid, or worst case: leaky seals throughout. Transgo HD2-C kit fixes first two without removing trans. Seal restorer may fix last problem, but probably R&R. Also try a transmission flush with BG brand products (Firestone stocks it).

17. No forward movement in OD or D, but L2, L1 and R work: Forward sprag is broken. R&R. Try not to run or drive the car or further damage could result.

18. Extremely harsh shifts from P or N, normal shifts at WOT: EPC (Electronic Pressure Control) solenoid failed. Easy fix in pan. Fix as soon as possible or hard parts will eventually break.

19. Loud bang, grinding sound, loss of all gears, and a binding driveshaft: snapped output shaft. Try to wiggle driveshaft - if more than 0.020" play, that's the sign. R&R.

20. Trans seems noisy when moving in 1st and Reverse, noise goes away instantly if you shift to N or the trans goes into 3rd gear: Reaction planetary is worn out due to high miles or insufficient lubrication. Not a critical failure, but not a good sign either. R&R sooner rather than later.

21. No movement in any gear: pump failure, or total loss of fluid. R&R, or refill pan and find the leak. If out of fluid, avoid running the engine until the trans is refilled to avoid pump damage. To check for pump failure, check fluid level with the engine off, then start the engine and recheck fluid level. If level does not go down when engine is running, the pump is broken.

22. Transmission does not shift automatically, only manually. Swap in a known-good PCM, check wiring, check other sensors such as VSS and TPS.

23. 3rd gear starts, can manually shift through all gears. When car has been turned off for a bit, then back on it will run normally.: VSS dropoff w/ Hi-stall converter. The rpms are too high, but VSS is showing no movement. Happens after a tire burning take-off. Doesn't store a code, will not throw a CEL (I've heard that it will store a code if it happens 3 or more times). Cure: Reprogram PCM for VSS dropoff -- PCMforLess knows about it.

24. Fluid leak out of the front of trans where the converter connects; partial or full loss of movement: Front pump bushing walked out. R&R. May have to replace converter also if hub is scored. Note that a leaking front seal usually means the bushing is walking out (i.e. call your local trans shop and schedule an appt.).

25. Torque converter shudder in 4th while lockup is engaged; problem goes away when the brake pedal is pressed slightly to unlock converter. Have a shop verify line pressure, and provided no valves in the TCC hydraulic circuit are worn, replace the torque converter. Also, Lubegard Shudder Fix will at least fix this for awhile. Or try a transmission flush by a shop that uses BG brand products.

26. Shift suddenly become very hard. When going from park to either reverse or drive it slams into gear. 1-2 and 2-3 shifts are also harsh. All gears seems to work. Problem may be intermittent: Check TPS for smooth electrical response. If the response is jumpy or erratic at all, replace TPS.

27. All fluid pumped out through the vent tube: Plugged cooler line. Flush the transmission cooler and cooler lines. Also could be overfiled transmission.

28. Car acts like it's in OD in neutral, car is locked stationary in R, engine feels loaded in P, all four forward positions work fine: R&R: Internal crossleak feeding the forward clutches all the time. Most likely a cracked input housing, or cracked forward piston means forward clutches are fused together. Car can safely be driven gently in forward gears until the repair.

29. Needle bearings in the pan, first gear and/or reverse may be noisy: Either a torrington bearing or a planetary bearing is on its way out. Trans will eventually die a loud, catastrophic death. Cheaper to rebuild now (saves further damage to hard parts), but requires R&R. It is drivable until it breaks.

30. 1-2 or 2-3 shift is slow/soft above part throttle: Trans is on its way out. R&R.

[ScarabEpic22]

I can see the shift happen on the scanner so the software is doing it's thing.

What is not happening as I explained above it the ground is not being taken away from pin 48 or the Green wire for the 1-2 solenoid, if I cut the wire it shifts.

I can move the shift points around and see the change in the scanner the 1-2 shift solenoid changes from on to off right where I command it to so this is not a programming issue.

Seems to be an operating system or hardware issue with in the PCM.

I have tried a second PCM with the same program and the same results.

My gut tells me something is getting screwed up by the 2 bar operating system.

I have another PCM here I just bought for a 1/2 ton van with 4l60 trans that I may try when I get a chance but I don't expect a different result.

PCMPOWERTUNES provided this computer, swap package, and has tried to help to no avail.

Ted.

Gotcha, so it shifts IF you remove gnd from that pin during the shift. So not a programming issue as the scanner reflects the change properly, the trans just doesnt shift (until you remove gnd from that pin). I was thinking it might have been a mechanical issue with the 1->2 shift, seems that's not the case (good thing!).

Can you downgrade to the regular, non-2Bar, OS and see if that fixes it? Not the ideal state as the vehicle has a blower...


Mrich0908, when you stopped by, did you put your PCM in the problem vehicle and see if it worked properly? Do you have your PCM upgraded to 2Bar OS as well?

[Mrich0908]

Gotcha, so it shifts IF you remove gnd from that pin during the shift. So not a programming issue as the scanner reflects the change properly, the trans just doesnt shift (until you remove gnd from that pin). I was thinking it might have been a mechanical issue with the 1->2 shift, seems that's not the case (good thing!).

Can you downgrade to the regular, non-2Bar, OS and see if that fixes it? Not the ideal state as the vehicle has a blower...


Mrich0908, when you stopped by, did you put your PCM in the problem vehicle and see if it worked properly? Do you have your PCM upgraded to 2Bar OS as well?

No , Im swapping his tune over to my ecm . I run a 2 bar sd conversion on my turbo motor no problems. Im not sure why the 2 bar would mess with his 4l60e shifting and not mine.
The swap he did is meant for this engine. Its not a a user swap but a GM swap. He has a gen 1 sbc using a 0411. GM used the ecu w/gen1 sbc in express vans . His motor is obd2 the van is obd2 . It was a matter of re-pinning the ecm only. All sensor and what not go to that ecm.