2000 Silverado 4 codes

[Mod_12]

Question for the experts,

all dash lights and gauges went crazy with a picture of battery in screen and then stopped working for a few miles before working again. I was cruising @65 and this happened and downshifted to 2nd then quickly to 3rd and wouldn't shift again. Stuck in 3rd gear. Had it scanned and got P0740,P0753,P0758,P0785. all shift solenoids. Would I just buy a new valve body with new solenoids? I would occasioally have the gauges go crazy and battery light go on but would go away and not have any codes stored. It would only do it towing and always thought it was a ground issue with the trailer but appently it wasn't 178,000 miles on truck. After I scanned truck all is working well for now.

[j cAT]

I am guessing that the ignition switch is the problem or the ignition feed circuit is with a bad connection . If someone screwed with the OEM wiring this could be the reason. alarm/remote start/audio hi power amp etc...other hi power electrical loads.

this is what many have found with your issue posted. it is at that age for the switch to be worn out. base of steering column. good luck

[rhandwor]

Originally Posted by Mod_12

Question for the experts,

all dash lights and gauges went crazy with a picture of battery in screen and then stopped working for a few miles before working again. I was cruising @65 and this happened and downshifted to 2nd then quickly to 3rd and wouldn't shift again. Stuck in 3rd gear. Had it scanned and got P0740,P0753,P0758,P0785. all shift solenoids. Would I just buy a new valve body with new solenoids? I would occasioally have the gauges go crazy and battery light go on but would go away and not have any codes stored. It would only do it towing and always thought it was a ground issue with the trailer but appently it wasn't 178,000 miles on truck. After I scanned truck all is working well for now.

I would check your grounds upper right and upper left kick panel for the dash lights.
right rear of engine,left frame body mount bracket,left rear of engine,left front of engine.

[Mod_12]

Only aftermarket part in the truck is a brake controller and it is a plug in not spliced in. Never had any of the wiring harness touched anywhere on the truck. I have no amp, stereo, all factory items. I bought the truck from a Chevy dealer with 12000 as demo in 01 so I doubt and thing would have been done there. Will check the switch and all of the grounds.

[maxwedge]

Make sure you have power to the main plug on the trans,or it is loose or corroded. Also look at the fuses, the trans is in limp mode.

[Mod_12]

will check the plug connection today, but it seems to start out in 2nd gear and has hard shifts. I heard that the valve body's wear out in the transmissions. Is this common? also shifting used to be around 32-35 from 2nd to 3rd now it seems to shift 40+ and acts like it is trying but keeps winding out until it shifts.

[j cAT]

Originally Posted by Mod_12

will check the plug connection today, but it seems to start out in 2nd gear and has hard shifts. I heard that the valve body's wear out in the transmissions. Is this common? also shifting used to be around 32-35 from 2nd to 3rd now it seems to shift 40+ and acts like it is trying but keeps winding out until it shifts.

because you got the battery light to come on and all those tranny codes then I guessed it is the ignition switch or feed being the cause. the brake controller if on the vehicle and was used to apply brake power to a trailer is an added current load this causes ignition switch load current to increase.

[j cAT]

Originally Posted by Mod_12

will check the plug connection today, but it seems to start out in 2nd gear and has hard shifts. I heard that the valve body's wear out in the transmissions. Is this common? also shifting used to be around 32-35 from 2nd to 3rd now it seems to shift 40+ and acts like it is trying but keeps winding out until it shifts.

you may have transmission wear issues with the valve body and other components if you have used DEXRON III. this fluid after 20,000 miles has been reported by GM and others to turn into an acidic fluid. then the damage begins. GM in 2006 dropped this fluid to the now dexron VI fluid. they did not inform us of this change. so now many have had to spend for a new/re-built transmission. I stopped using dexron III back in 1998. I only use mobil synthetic transmission fluid for GM vehicles.

checking the transmission wiring is a good idea but that would not cause the battery light to come on.

[Mod_12]

well, today I lost 1st and 4th gears. I was in the process of fixing other items while it was still running ok. I am going to change the ignition switch but unsure of the connector? 10 or 14 pin. I just called to order the part and they asked what connector. I haven't started to take apart yet . Also about how long would the job take to do? All I have seen online were 10 pin connectors.

[Mod_12]

installed ignition switch and problems went away

[j cAT]

Originally Posted by Mod_12

installed ignition switch and problems went away

good job !