95 suburban electrical issues

[Meangreen]

My suburban recently started up and had no 1st or 4th gear.it drove fine from the job site to hone depot,appx 25 min drive ,came out started it up and no 1st.the problem wasoff and on ,always after I drove somewhere and shut it off.1st start in the morning never had the problem .had some codes pulled 64,66,81,82,83.that odd part is when I bought the truck the check gage light was on and has been due to bad cluster or something of the nature.my shifting problems occurs when the check is not on so I believe it's a bad connection or electrical component. But the dealership said I need a new tranny, even tho they didn't try pulling codes or checking for power to and from tranny.what should be my next step prior to trying a different tranny

[carriedi]

you have to do a lot of circuit testing for those codes. And, you have to check the circuits when it is acting up. Without the wiring diagrams for those circuits and a lab scope to watch them (or a multi trace dvom) I don't know how you would be able to find the problem.

I would drive it with a scanner graphing the data stream while watching the lab scope to see what the circuits are doing.

dtc 82, 1 - 2 shift solenoid circuit fault, once set will only allow 2nd and 3rd gear or only allow 1st and 4th. The code will be stored in memory but will not turn on the MIL.

dtc's 64 and 66 could turn on the check engine light and put the computer in limp mode which could make the trans not shift normally also

[Meangreen]

Well now always like this .the check gage light doesn't even appear when ignition is on truck is off.I think the cause of this whole thing is from driving thru a a small lake (not really a lake).I was on the highway and under an underpass was flooded so I chose to stay in the fast lane and push thru it instead of fighting to get in the carpool lane.I'm taking it to get the codes pulled again this weekend and find time to start checking for disconnections or breaks in lines

[carriedi]

That new information could be helpful. Most connectors and components come with water resistant seals but a 1995 vehicle, the seals are, more than likely, are aged and no longer good seals. You may have a water intrusion problem. Has the weather been dry enough to dry out any water that may have gotten into parts underneath the truck?

[Meangreen]

Yea it's been pretty dry here ,I haven't been driving the truck alot since the problem is consistent. Actually about to head to aamco in a few mins so I will post new codes in a couple of hours

[Meangreen]

Ok so had codes pulled ,when I said code 64 it was actually 67,couldn't tell if it was a 4 or 7 .anyways 4 of the 5 from last time came up. 66,67,81,82 .83 didn't show this time.since the 1st testing I did a and b shift solenoids and output speed sensor. I found info on the codes and they all say can be from wiring,solenoid ,or ecm

[carriedi]

right, that's why you need to see what the voltages are in the wiring to the trans solenoids.

Is the computer sending the correct signal? Is the solenoid getting the correct signal? Is the solenoid reacting correctly to the signal? A transmission shop should have a tool that connects to the trans and they can control the trans and see if it will react to the commands that they give it. If it all works fine then the problem would be in front of the trans connector.

[Meangreen]

At this moment I have the harness disconnected from the tranny and the sensors ,I pulled it up to the engine area so I can check the wires and such befor I pay a shop 200 to find my issue

[carriedi]

what engine and what trans do you have in your truck? 2 or 4wd?

[Meangreen]

It's the c1500 ,5.7 ,4l60e tranny,just 2 wheel

[carriedi]

see if this will help

[Meangreen]

I'm going to print it now.thanks for your help.common problem ,many different solutions lol.I'm tracing wires for continuity