electrical problem transmission flaring?

[MrIgor]

i have a 2003 h2. I bought it with the gears flaring (reving between shifts) No error codes. I replaced it with a rebuilt transmission, and same problem with flaring. I brought back the 2nd transmission they gave me another built transmission... installed it today and SAME PROBLEM! it revs between gears, (but shifts smoothly, after reving up 1000rpm obo).

I replaced the PCM, got it programmed at the dealer (all pins are perfect on the pcm)

What can cause this problem?

[PaHumBug]

I don't know but it sounds like it's not the tranny. I know you can adjust how soft and hard it will shift with a programmer, you could try that.

[jsbihn]

Ok,
So if I understand correctly, you are stating that the transmission worked or works fine except in between gears? That when you shift from say 1st to 2nd it will stay rev or stay in nuetral longer?

I assume that you installed the tranny and replaced all fluid that go with it?
This is a common problem if the fluid is too low.
Also did you check to see if the trans cooler is leaking?
And also did you check to make sure that it was pressurizing and such?
The trans might be good but if the fluid isnt getting there........

Also how long has it been since you have cleaned your TB and MAF?
This might be a solution.
I know it might sound stupid but alot of times the MAF doesnt get the right signal in between shifts and it over revs.

[MrIgor]

it revs between all gears feel like neutral longer. Otherwise it works perfect. New torque convert with tranny. New fluid. new larger cooler with new lines.

Cleaned the TB. Inspected MAF, looks clean. (installed new k&n intake, no change)


all 3 Transmissions had 0 codes. Transmissions are new inside, i saw both transmissions get built in front of me.


Questions: Aftermarket Programming can remove the rev flaring? (I have new PCM that was programmed at dealer)

[MrIgor]

If someone can start their hummer, and disconnect the negative cable from battery tell me if the gauges on dash, stereo work etc.. ( the truck will not shut off). Trying to test out my alternator.


Also If I disconnect my MAF I see no difference in idle or acceleration.

[jsbihn]

Ok, not sure why you are checking the ALT in regards to your transmission issue.... but then again who would think that a MAF would cause issues either....

With that said, if you unplug the MAF the ECU will get signals from temps, rpm, barometric pressure, and tps sensor readings to make a calculation of what amount of fuel should be injected. As long as the engine isnt all out modified and running iwith a new program, it shoud actually run pretty well without the MAF. Of course, if weather conditions, pressure, elevation, etc. change, the MAF will make the ECU adjust alot better then trying to caluclate which will make the engine run better.

Given, I am wondering if you drive the vehicle with the MAF unplugged do you still get the in between shift surges? I would think that if you didnt, it would be definitely the MAF and though it is cleaned could be signs it is bad.

[MrIgor]

Originally Posted by jsbihn

Ok, not sure why you are checking the ALT in regards to your transmission issue.... but then again who would think that a MAF would cause issues either....

With that said, if you unplug the MAF the ECU will get signals from temps, rpm, barometric pressure, and tps sensor readings to make a calculation of what amount of fuel should be injected. As long as the engine isnt all out modified and running iwith a new program, it shoud actually run pretty well without the MAF. Of course, if weather conditions, pressure, elevation, etc. change, the MAF will make the ECU adjust alot better then trying to caluclate which will make the engine run better.

Given, I am wondering if you drive the vehicle with the MAF unplugged do you still get the in between shift surges? I would think that if you didnt, it would be definitely the MAF and though it is cleaned could be signs it is bad.

if i unplug maf, i dont get any check engine light or error codes (i scanned the truck)




If I start truck and disconnect positive or ground from the battery in about 30 seconds my speedometer and stereo start turning off and on... but wont die.

[New York City]

I swear I am having the same identical problem.
And I do mean identical.

Everything you have stated.


How much did it cost you to get programmed at the dealer?

[jsbihn]

Igor,
I am wondering if when you had your tranny replaced did you have the oil pump for the tranny replaced.
As I mentioned in NYC's post it could be the pump... could have been the whole time.
Also, I would think that if you have disconnected your battery and the truck runs and cycles thats good. Maybe your Alt isnt as strong as it should be and it pulls a little from the battery (which I have heard that this is really the case in the H2), so if so I would think that the electricals would start to cycle on and off without the battery because the Alt isnt making the juice it needs to.

(again this is a common thing from what i heard. the alt is under-powered and it will suck from the battery, so of course another reason why alot of people with extra lights, extra electronics or stereo systems go through lots of batteries.)

hope this helps

[MrIgor]

The problem has been narrowed down to the MAF sensor. If you unplug it the transmission shifts good. If you plug in the MAF it slips

[jsbihn]

Glad I could help narrow it down to fix.

[Lean Machine]

I currently seem to be having a similar issue with my 2005 H2. I seem to have developed electrical problem since I had the battery changed a few weeks ago. I've had multiple problems (blown ignition fuse, replaced ignition, etc.) The only remaining problem is the transmission. Initially after getting the battery changed, the transmission would skip 1st gear and go straight into 2nd gear. No issue moving from 2nd gear to 3rd gear, etc. A few days later the battery was disconnected again so another shop could work on the after market alarm system. When I got the rig back the transmission starts in 1st gear but doesn't shift from 2nd to 3rd gear. RPM surge between 2nd gear and 3rd, but doesn't return to normal until tranny moves to 4th gear. Current shop says the transmission needs to be replaced, but I don't believe this is all a coincidence that the transmission went bad the same day I had the battery changed. This thread was a little dated. Any updates if you've had similar issues?
Thank you

[HUMTECH]

Scan it for codes, sounds like transmission may be in default. Could be due to loss of ign 1 power from the ignition switch to transmission. Seen this lots and seen many transmissions replaced due to it being a 40 dollar switch. It can also be caused by your remote starter especially since it happened after a battery disconnect which can sometimes cause them to fail or go into a default mode.

[HUMTECH]

Condition
Some customers may comment on one or more of the following conditions:

?The Malfunction Indicator Lamp (MIL) is ON.
?The transmission is defaulted to second gear (4L80/85-E).
?The transmission is defaulted to third gear (4L60/65-E).
?The instrument cluster is inoperative.
Upon investigation, one or all of the diagnostic trouble codes (DTCs) P0740, P0753, P0758, P0785, P0787, P0973, P0976, P1860, P2761, P2764 and P2769 may be set depending on the vehicle.

Cause
The most likely cause of this condition may be a loss of voltage to the transmission solenoid power supply circuit.

This condition may also be the result of an incorrect installation of an aftermarket electronic device such as a remote starter or alarm system.

Correction
Important: If the vehicle is equipped with an aftermarket electronic device and the DTCs are being set when the device is being used, verify that the appropriate fuse is being supplied battery voltage during operation. If voltage is not present at this fuse, these DTCs will be set due to lack of voltage at the solenoids. This condition is most likely to occur with an incorrectly installed remote starting system. If this is the case, refer the customer to the installer of the system for corrections. ANY REPAIRS DUE TO AFTERMARKET INSTALLATION OF ACCESSORIES IS A NON-WARRANTABLE ITEM.

 1. With the ignition switch in the RUN position, test for battery voltage at the circuit fuse in the transmission solenoid power supply circuit. Refer to the appropriate SI Document for the transmission solenoid power supply circuit information.
 2. If battery voltage is present at the fuse, inspect the ignition voltage circuit between the fuse and the transmission for possible opens.
 3. If battery voltage is not present at the fuse, test for continuity between the fuse and the ignition switch. If NO continuity is between the fuse and the ignition switch, repair the open in that circuit.
 4. If you have continuity between the fuse and the ignition switch, the most likely cause is the ignition switch. Replace the ignition switch using the appropriate Ignition Switch Replacement procedure in SI. Refer to group number 2.188 of the parts catalog for part description and usage of the ignition switch.

[Lean Machine]

Originally Posted by HUMTECH

Condition
Some customers may comment on one or more of the following conditions:

?The Malfunction Indicator Lamp (MIL) is ON.
?The transmission is defaulted to second gear (4L80/85-E).
?The transmission is defaulted to third gear (4L60/65-E).
?The instrument cluster is inoperative.
Upon investigation, one or all of the diagnostic trouble codes (DTCs) P0740, P0753, P0758, P0785, P0787, P0973, P0976, P1860, P2761, P2764 and P2769 may be set depending on the vehicle.

Cause
The most likely cause of this condition may be a loss of voltage to the transmission solenoid power supply circuit.

This condition may also be the result of an incorrect installation of an aftermarket electronic device such as a remote starter or alarm system.

Correction
Important: If the vehicle is equipped with an aftermarket electronic device and the DTCs are being set when the device is being used, verify that the appropriate fuse is being supplied battery voltage during operation. If voltage is not present at this fuse, these DTCs will be set due to lack of voltage at the solenoids. This condition is most likely to occur with an incorrectly installed remote starting system. If this is the case, refer the customer to the installer of the system for corrections. ANY REPAIRS DUE TO AFTERMARKET INSTALLATION OF ACCESSORIES IS A NON-WARRANTABLE ITEM.

 1. With the ignition switch in the RUN position, test for battery voltage at the circuit fuse in the transmission solenoid power supply circuit. Refer to the appropriate SI Document for the transmission solenoid power supply circuit information.
 2. If battery voltage is present at the fuse, inspect the ignition voltage circuit between the fuse and the transmission for possible opens.
 3. If battery voltage is not present at the fuse, test for continuity between the fuse and the ignition switch. If NO continuity is between the fuse and the ignition switch, repair the open in that circuit.
 4. If you have continuity between the fuse and the ignition switch, the most likely cause is the ignition switch. Replace the ignition switch using the appropriate Ignition Switch Replacement procedure in SI. Refer to group number 2.188 of the parts catalog for part description and usage of the ignition switch.

Ignition switch replaced. Transmission shifting issue remains. I still think the issue is electrical, but having a transmission shop take a look just in case.