99 blazer 4x4 trans problem is the same after swap?

[fine69lc]

I have a 99 blazer 4x4 with the 4 button auto 4x4. The trans. started shifting funny. It would start out fine, with a hard,late shift to 2nd, then 3rd, then would not downshift until it had stoped and sit for a while. There was also a growling sound that seemed to be coming from the front end of the truck, about the same sound as very aggressive tires on the pavement. The abs light then came on intermittantly and the speedometer quit as well. It would also get stuck in 4x4 and changing the buttons wouldnt make it come out.(had to pull fuse). I decided it was time for a new (used) tranny and transfer case, because both were acting up. I did the swap, and other than being stuck in 4x4 all the time, the symptoms are all the same. Im no better off now than before I did the swap. I have put the vss sensors in, and the tps as well. Where does my problem lay if it wasnt the items above? Any help is appriciated.

[MT-2500]

Originally Posted by fine69lc

I have a 99 blazer 4x4 with the 4 button auto 4x4. The trans. started shifting funny. It would start out fine, with a hard,late shift to 2nd, then 3rd, then would not downshift until it had stoped and sit for a while. There was also a growling sound that seemed to be coming from the front end of the truck, about the same sound as very aggressive tires on the pavement. The abs light then came on intermittantly and the speedometer quit as well. It would also get stuck in 4x4 and changing the buttons wouldnt make it come out.(had to pull fuse). I decided it was time for a new (used) tranny and transfer case, because both were acting up. I did the swap, and other than being stuck in 4x4 all the time, the symptoms are all the same. Im no better off now than before I did the swap. I have put the vss sensors in, and the tps as well. Where does my problem lay if it wasnt the items above? Any help is appriciated.

Do what you should have done to start with.
get it on a transmission/engine /abs capable scanner and see where the problem is.
The speedometer problem will need fixed befor transmission will shift right.
post back and codes.

[fine69lc]

I have a craftsman brand scanner. Pulls a Vss low input. I dont have access to one of the really really exspensive scan tools. I thought this one would do it all for the nearly 400 bucks I spent on it. Im thinking the pcm is shooting craps. What else could it be?

[blazes9395]

Like MT said, that speedo must be working right for the trans to shift properly, or even for the 4x4 to work properly. You need a scanner to to see what is going on. Get the speedo working first, and go from there.

[old_master]

I agree, the cheapie code readers barely scratch the surface when it comes to data access and retrieval. You'll need to have it scanned with a good one. Either pay someone to check it or spend $5K or more on a decent one. Agree also on the VSS issue: the ECM uses that data for TCCM, speedometer, engine performance, & transmission shifting, just to mention a few.

[fine69lc]

List of codes thrown.

p0452 Evap Emission system pressure sensor low. (unrelated)

p0740 torque converter clutch solenoid circut

p0785 Shift/timing solenoid

p1860 pwm solenoid circuit

p0502 VSS A circuit Low input

4x4 issue was solved with trans and transfer case swap. Transmission however still shifts the same as the old one. I know the trans I put in was fine as I test drove it right before the swap. Speedometer worked before swap too. Abs light is now off since a few test drives with the new vss sensors.

[MT-2500]

Did you use same year and right transmission?
Have you check power feeds and wiring to transmission?
Any bad fuses?

[old_master]

Is that the exact order the DTC's were retrieved? DTC's must be diagnosed and repaired in the order they are retrieved. Then clear all DTC's, perform a drive cycle, and re-check for DTC's to confirm the repair. If additional DTC's are present, repeat the same process until no more DTC's show up.

[fine69lc]

Same year and model blazer. I have checked all the fuses, and ran all the wiring down. Seems to be fine.

Yes, that is the order of the codes. I typed them right off the scan tool. It has to be electrical to be doing the same thing after the swap. I guess the pcm runs the transmission on these? I know its not the transmission, Its whatever tells the transmission what to do. Thank you guys for all responces. Im ready to figure this dang thing out.

[old_master]

P0740 torque converter clutch solenoid circut, P0785 Shift/timing solenoid, and the P1860 pwm solenoid circuit are all DTC's relating to 3 of the 5 solenoids in the transmission. You're right, the fact that it acted the same way with the old transmission means it's probably something electrical. All shift points are controlled by the ECM. All 5 solenoids inside the transmission get battery voltage from the same wire. On the trans case there is a round connector with several wires in it, (you had to disconnect it to remove the trans). With the ignition in the RUN position, check the pink wire, it should show battery voltage at the connector. The pink wire changes to red inside of the trans. There is a splice connection that runs the red wire to one terminal on each of the solenoids. No need to drop the pan and check the red wire, more than likely it's ok.

[fine69lc]

Thanks, ECM cleared all the transmission problems. There is still the growl/whine in the front end. It starts at 20mph and gets consistantly louder the faster it goes. Clicked it in nuetral at 55mph and it growls in nuetral too. Ive already unhooked the vacume from the deal under the battery box, it is working as it should. It has new hub assemblies, and cv shafts. The sound is like aggressive mud tires on a paved highway. Thats the best way I can explain it.

[vikingdaddy1]

Wheel bearing?