GMC Envoy P0894 Slipping transmission

P0894 code I have 2005 GMC Envoy. I already changed fluid and filter when driving it will shift in 1st and 2nd fine then when gets to 3rd it will just idle real high like it’s in neutral.

I have to keep giving gas and letting off until it hits gear. Is my trans shot or what all may it be?

ANSWER: P0894 code is a trouble code signaling a problem with a transmission component slipping. The powertrain control module is responsible for changing the gear ratios of the automatic transmission, as this helps control the vehicle’s speed, acceleration, fuel economy, and performance. When the ratio in one of the vehicle’s gears is not seen to be consistent with the what the PCM wants to see, the P0894 trouble code will be set.

You would have to have a mechanic scan the computer live data to watch what the transmission is doing and what the computer wants to see. Most of the time the problem actually is an actual component in the trans is causing a slip. In that case it would have to be removed and repaired. This will be an expensive repair.

Another possibility is that one of the shift solenoids has failed. But that cannot be diagnosed without a scan tool either. Also the mechanic will remove the pan and do some electrical testing on the solenoid. Specifically, an ohm reading. This will tell him right away id the problem is a solenoid or not. A shift solenoid is a fairly inexpensive repair. They cost about $80 plus 2 hours of labor as compared to a transmission overhaul of $1500 or more depending on if you go to a local shop or a dealership.

The fact that you can get it to shift by letting off then hitting the gas again makes me think this is a failing component inside the transmission and an expensive repair is in order.

REPLY: 2005 envoy, my car only has second and third when car hits 3rd it will just rev up until it ends up back in second. Changed fluids and filter didn’t help didn’t see no metal shavings in pan. 2005 envoy I have a bad camshaft sensor will that make my car not go into 3rd and 4th gear?

ANSWER: Yes, read above. Sounds like internal component problem. No, cam sensor will not cause your problem.

2005 envoy just bought car don’t know much about it. Only first and second gear will work fine automatic, or if I shift manually once it tries to go to 3rd gear it will jus rev up loud and eventually it goes back into second will not hit third at all. I changed the trans fluid and filter didn’t see no metal shavings in pan. Would this be a bad solenoid or would it mean that the clutch or something is burned out thanks.

GMC Jimmy Shudders

I have a automatic GMC jimmy and the truck shudders when accelerating in 1st but as soon as it shifts into 2nd the shuddering/missing completely stop and run perfect. It kinda feels like its not getting enough fuel. I changed the fuel pump and fuel filter around 10 months ago.I occasionally have to try and start it a few times before it will start. I would greatly appreciate it if you could get back with me. Thank you very much.

ANSWER: This may just be an ignition problem since that usually shows up under high engine load. I would suggest do a tune up first then re-evaluate the shudder condition before you condemn the transmission.