Hi, my automatic ‘98 Blazer LT 4WD won’t shift out of 1st gear when accelerating.


The moment it reaches around 2000 RPMs, it doesn’t shift into 2nd gear, but instead the RPMs climb up to 3000 and beyond if I give it more gas. At this point, the car stops accelerating and behaves like it is in Neutral.


Top speed is about 10 mph while going on uphills.


It stays in 1st gear no matter if I set it in Drive, 3rd, or 2nd gear. In 1st gear, I can feel the car engage and slow down more distinctly than the other gears. I can’t get it to manually shift up either.


Reverse gear, Park, and Neutral all work fine.


A few weeks ago, the speedometer began acting up, flickering between 0-30 mph, and then working normally once I hit 40 mph. Not sure if this would be linked.


I noticed starting last month that the car would rev up higher than usual when shifting from 1st to 2nd gear.


Odometer on the car reads around 166,000 miles. Transmission fluid and filter were changed about 5,000 miles ago. Fluid was black, but no large particles, and no transmission issues until now.


I replaced both shift solenoids, but this did not fix the shifting problem. I also did another fluid change after replacing the shift solenoids. Transmission fluid does not smell burnt after driving it.


I saw saw another post mention issues with the ignition switch being the cause. Or the DRAC module. Would that apply in my case?


If you need more details, please feel free to ask and I will do my best to include them.


Forgive me if I included any incorrect terminologies. I just started working on the Blazer myself about 6 months ago, I’m a beginner here, so I figured it would be helpful to get advice from more experienced fellow Blazer owners.


Any help or tips would be appreciated.


Thanks!
Donald

 

Welcome Donald, if you have a service engine soon light on more than likely it will have a code stored. Need to have it scanned. A cheap code reader wouldn’t get the transmission codes usually. Yes if speedometer is malfunctioning it will cause shift issues like you describe. No DRAC module on your vehicle. Get it scanned and let us know what codes you get.
Brad

 

Hello Brad! Yes, the check engine light is on. I scanned for codes with a basic Autel OBD II and CAN code reader that I had on hand, and only got one code: P0452 “Evaporative Emission System Pressure Sensor / Switch Low”

 

A friend has a neighbor who owns Blazers, and he said to replace the speed sensor if replacing the shift solenoids did not fix the problem.

Just replaced the speed sensor, and now the car shifts great! It also fixed the issue I was having with the speedometer.