no automatic shift

[95k150050]

i have a 95 k1500 5.0 with 4l60e 4x4. it will not shift automatically but i can shift it manually. i have a check engine light however can not pull codes. i jump terminals a and b on the diag connector and as soon as i turn the key on, it check engine light just flashes once and thats it. any advice? im thinking computer or shift solenoids truck has 189k on it

 

[Jglew82]

You are probably exactly correct on the issue, but it could be other issues such as TPS, VSS etc - hard to say without knowing the DTC. Run up to autozone or whatever is close to get your codes pulled.

 

[94burbk1500]

You are probably exactly correct on the issue, but it could be other issues such as TPS, VSS etc - hard to say without knowing the DTC. Run up to autozone or whatever is close to get your codes pulled.

I don't think 95 was true OBDII

 

[Jglew82]

I don't think 95 was true OBDII

OP's for sure isn't since they mentioned terminal shorting on A/B. Some places are still able to scan the aldl, but you might have to call around.

 

[98chevy2500SS]

Might be the ignition switch causing this, but you would have had codes pop up, 4 if I am not mistaken. My 97 started doing this sometimes, went into limp mode/manual. Replaced the ignition switch and it is finally shifting like it should. Does your RPM/Speedo/Odometer not work when this happens? If so, replace ignition switch.

Edit: These codes would have popped up: P0753 (Shift Solenoid A Electrical); P0758 (Shift Solenoid B Electrical); P1864 (DTC Definition Not Found); P1806 (DTC Definition Not Found)

https://www.1aauto.com/chevy-gmc-ignition-starter-switch/i/1azis00005?f=441749&y=1995

 

[evilunclegrimace]

i have a 95 k1500 5.0 with 4l60e 4x4. it will not shift automatically but i can shift it manually. i have a check engine light however can not pull codes. i jump terminals a and b on the diag connector and as soon as i turn the key on, it check engine light just flashes once and thats it. any advice? im thinking computer or shift solenoids truck has 189k on it

Unplug the TPS and see if the computer recognizes the fault. If it does the ECM is most likely ok. If it does not then the ECM is suspect for being defective.

 

[PlayingWithTBI]

I don't think 95 was true OBDII

^^^It's not. It is a 16 pin OBD1. 96 went to the OBDII

 

[94burbk1500]

OP's for sure isn't since they mentioned terminal shorting on A/B. Some places are still able to scan the aldl, but you might have to call around.

I've never found a place with aldl cables, but I also haven't tried all that hard.

 

[PlayingWithTBI]

I've never found a place with aldl cables, but I also haven't tried all that hard.

http://aldlcable.com/aldl.asp

 

[95k150050]

That's the thing. The cel never flashes at all so that's why I'm thinking the computer?? Also when I got the truck the tps was just laying on the intake so I found some bolts and re installed it, re connected the battery and as soon as I start it cel on but it will not do the flash dance for codes when I jump a and b on diag port