I have a 2001 Dodge Ram 1500 Lariat 4X4, was having tranny issues (long shift from 2nd, and rough running uphill at 70kms) and code P1765, changed the shift solenoid and transducer with oem parts, atf-4 and new filter, problem solved, no code, days later, truck went into limp mode, pulls away in 2nd, light comes on for overdrive but no change in RPM, code P1765 is back, I battery reset and turned key on, code back again. Stumped, but I was also informed that maybe the O2 sensor may be toast, as it uses the same electrical error to pcm as the shift solenoid??

Any help would be appreciated...

 

O2's have their own codes.

P1765 Trans 12 Volt Supply Relay CTRL Circ

The PCM is whining about the power supply to the trans. There is a fuse, and a relay in the Power Distribution Center (black box behind battery). Make sure both are good.

 

Thanks, haven't checked either of them, I had 2 other codes, not sure if they relate to it or not P0443 and P1495

 

P1495 Leak Detection Pump Solenoid Circ

P0443 Evap Purge Solenoid Circ

I would start looking hard a fuses.

 

I will start there in the morning, update to follow

 

Ok I switched around the relays, fog lights for Tranny fuse, reset battery, checked codes, all clear, started truck, idled for a bit, went thru the gears couple times, shut off truck and codes didn't return, codes I did have were P0622, P0443, P0138, P1762, P1495
Will run the truck this weekend to see if I can't get it to act up again

 

A shorted out downstream 02 can cause both p1762 and p1763 transmission codes because I had them on my old red 99. I thought the guy at O'reillys didn't know what he was talking about, so I looked into it more. Limp mode only lasted a short while when I got these codes, but I did find others whose downstream 02 was the culprit. Apparently it's just the downstream 02 that's on the same wiring path as some transmission sensors.

 

Ok to date, I have had the following codes:

P0622
P0443
P0037
P1763
P1495

I have changed the Governor Pressure Sensor, Transducer
I have changed downstream O2 Sensor,
I have cleared codes, multiple times,
I recently took it into Dodge, had them scan it, Mechanic could only find a wire for O2 sensor fouled, so he built a quick fix jumper and heat wrapped it, cleared codes, proved voltage, only codes coming up at this point are P0622, P0443, P1495, I leave dealership, get 3 kms away, back to limp mode, I pull over an check codes, damn O2 code P0037 is back as well as tranny code P1763.

I`m beginning to think the PCM is toast, everything works when I clear codes, but only briefly. Any feed back would be welcome

All fuses including relays have been checked and are ok

 

Pull the connectors off the PCM, and make sure they are all nice and clean. They like to corrode, and then connections become 'iffy'.

 

Connections all good, been pulled and cleaned, no corrosion, firm connect, current codes, been clearing them often, these always come back
P0622, P0443, P0037, P0138, P1763,

I have had 3 sensors changed, Governor Pressure Sensor, Tranducer, new filter and fluid, I have had this truck just recently into dealership for diagnose, new wire changed for downstream O2 and new dowstream O2 sensor installed, wiring tested for proper voltage to PCM. And still I get the codes thrown at me, truck loves to crawl into limp mode, stays there for a bit, then at higher speeds, all is normal except excessive fuel consumption, probably because of PCM errors reading sensors, throwing everything off, slight shudder in the idle, but not very noticeable.

I ordered a new PCM, start there, if that doesnt work, I will return and purchase a new harness. I'm out of options