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Chevy Blazer GMC Jimmy Maintenance and Repair



  • Do a search on google for 'transmission 1870' and the top 3 entries are all related to hard shifts.
  • AHH! I am at my wits end and hoping that someone with a previous expierience can help. I purchased my 1999 GMC JIMMY a little over year ago. I have had no problems with it, up until now. Of course, the warrenty is no longer in effect (isn't that always the way!) and my tranny seems to be gone. I had NO warning about this whatsoever, no previous slipping or problems, and all maintaince has been kept up to date, the care has truely been well taken care of.

    It started when reverse went out...completely. The rest of the gears are now sticking and slipping. Taking into the dealership I've been told that it needs to be rebuilt and the cost is going to be at least $1600. I have been researching online for the better part of the day and discovered that an incredible amount of Jimmy owners have had this same exact problem. Upon contacting GMC...they have assured me there is no recall on it, and I am on my own...of course. I have been to this website and about four others (including consumer affairs) and although there are many many posts regarding this action has been taken.

    What is the next logical step to getting GM to own up to what is clearly a big problem with the Jimmys and Blazers?!?!

    Thanks so much in advance!
  • DTC P1870 sets when the VCM (Vehicle Control Module) detects an unacceptable difference between engine speed and transmission output speed. Specifically, the DTC is triggered when the VCM discerns excessive torque converter clutch slip when the TCC should be engaged. The 4L60-E transmission has a TCC system that uses a degree of slip to smooth the engagement of the torque converter clutch. The VCM takes a number of actions when DTC P-1870 occurs. Among them: actuation of maximum line pressure, inhibition of TCC engagement, and no 4th gear shift when the transimission is in hot mode. All of this contributes to the hard shifting you experience. Although you mention the transmission has been serviced regularly, I would check the level and condition of the transmission fluid as a first step. If it is acceptable, the fix will require a thorough evaluation of numerous transmission components (shift solenoids, TCC solenoid, converter clutch valve, pump assembly, seals, etc.).
  • fenndfennd Posts: 10
    My '97 Blazer began shifting HARD from 1st to 2nd about 2 months ago while hauling a very light load in the back, right over the rear axle. Thinking it was just a fluke, I left it alone until it did it a 2nd and 3rd time. I took it to AAMCO and had a valve replaced (sorry, I'm not too familiar with the technical name), but the AAMCO man said it's a common failure in the Blazer/Jimmy transmissions. This thing aparantly distorts with heat over time, comprimising the pressure in the system, lending to the hard shifts.

    Before I dig myself deeper into what I don't know about, I'll finish by saying that I let AAMCO replace the valve for $119 and haven't felt a hard shift since.

    Hope this helps somebody.
  • I bought my 1999 ZR2 a year and a half ago, since day one i have had this problem that noone seems to figure out. when driving on a gravel road it bouces around too much the interior of the vehicle sounds like it is going to come apart, when driving on paved roads with cracks in it, it too does the same, the front end shimmys or vibrates alot. at times when coming to a stop sign or making a left/right hand turn a loud clunking sound can be heard even by a bystander outside the vehicle. Also there is a constant pounding that can be felt by the passenger on the floor,The lower balljoints have been replaced, Upper ball joints are tight.New shocks were put on front and rear. Everything on the front suspension seems to be tight. the noise that can be felt and heard coming from the R/front feels like a bad strut on a passenger car. Does the torsion bars have anything to do with this. this vehicle has been on the alignment rack many times and every time the same answer. Every thing apears to be tight.
     can anyone help with this?
  • I am looking at a 98 LS 4WD, 4 Dr Blazer. It runs really good and I had it checked out @ 2 different places plus the dealership checked it out. It has 72K and all the service records with it. It is in excellent condition. An older man owned it, and I actually called him about the Blazer and he told me in the 5 years he had it he replaced a water hose, new battery, and he put new tires on. He said it ran great for him. Right now I have a 2000 Lumina (piece of junk that burns a qt of oil in 5 days) with 63K. They are asking 10,988 for the Blazer, although I have 2500 negative equity in my car. The total price after trade but not including taxes is 10,525. Am I getting ripped off? The blazer comes with a 3 month 4K mile warranty. I don't know much about cars, please help!
  •      Price is OK with the trade. Low book is about $7700, & it's a high maintenance vehicle for most owners. Unless your winters have heavy snow you might want to consider another vehicle, especially since you've gotten along w/o 4WD thus far. If you can afford a new car & want a Chevy then try a Chevy Impala LS.
         I recently traded in my 1997 Blazer which served me well, but it had a fair amount of warranty service. Although new car payments are obviously more expensive than maintaining what I already had, the peace of mind I get with a new vehicle is why I got rid of mine.
         I gather you still owe on your Lumina & you may be getting rid of one problem & inheriting another. Tough decision. Good Luck.
  • spoomspoom Posts: 85
    Told 'em the gas gauge worked when it felt like it and gave them the last two recall notices (power mirror switch and seat belt ones) so they could have the GM dealer across the street "update" the vehicle on GM's dime. Picked up a new F 150 supercab 4x4. Truth be told, I think the similar GM Silverado gives more bang for the buck, but I will never give GM a dollar again because of the way I was treated over the years with this piece o poop Jimmy. If they had made things right to the tune of $300-something for the ball joints I would have considered the $30,000 + purchase of one of their products. Never mind the tranny, the wipers, the gas gauge, 2 of the 4 O2 sensors, or the endless SES light episodes, if they had treated me right I could have shrugged off the whole experience. Long after I forget the product I'll remember the company. Kinda a shame really, because it was quite a nice little truck when it was running-nice handling, wonderful ride, no rattles and better in snow than my 4Runner.
  • evolkevolk Posts: 9
    I am buying one this week, with oly 35,000 miles on it. Anything I should watch out for would be greatly appreciated.
  • dmetdmet Posts: 2
    Is there any way to stiffen the ride on my 1996 4WD/4door Blazer,besides replacing the shocks. It still rocks from side to side real bad. Can the torsion bars be tightened? If so, how?
  • Whatever you do, do not put 'LT' tires on as it will kill your ride. Stay with 'P' rated tires.
  • spoomspoom Posts: 85
    if you haven't already done so, take the time to read up on this whole thread. There's too much to go over again, but tons of things that kept cropping up on many different people's cars. Good luck. When they are behaving they are a great all-around SUV, but they can nickle & dime you worse than any vehicle I have ever owned (I'm 47 and have had at least a dozen) and the way GM treated me they will never get another dime from my household ever.
  • I am having problems with the fuel gage on my 1999 4wd Chevy LT blazer. I have a full tank and just about 3/4 tank full my gauge goes right to empty giving me a false reading. Im constantly having to stop and top off my tank on long highway trips is this a sensor problem inside the fuel tank or can this be an computer problem?? I need help.
  • cewecewe Posts: 2
    I own a 99 Blazer, and recently have been hearing a wierd engine sound (on and off). Especially when the engine is just turned on.
    I step on the gas to accelerate, and then step on the brake to make a full stop. The engine sounds is not normal, it sounds like the car's engine is about to die (for a good 5 seconds or so), but it never does (thang GOD). It happens for about 15 mins or so (as I drive along), and it (may) dissapear.
    I just changed the lower ball joints, front & rear brakes. Anyone has some ideas or has experienced the same thing ? Please advise.
  • Hey guys (and gals). I just took my mom's 1999 Chevrolet Blazer into a local dealer to get a tranny flush and oil change. While in the service bay, they informed me that the oil cooler lines were leaking, there was a vacuum hose leak under the dash that effects the HVAC system, and the serpentine belt was cracked. The car only has 63K on the odometer. Are these problems normal? I can understand the serp. belt, but the oil cooler lines?!? They wanted $400 to do those. I declined, needless to say. My grandmother's 2001 Blazer had the same problem, but replaced the lines with aluminum lines, I believe. Shouldn't this be a recall?? Or is it?? Any help is appreciated. Thanks a lot!

  • dmetdmet Posts: 2
    I think GM uses a vacuum module to operate the air vent system to direct the flow, for heat,defrost,a/c etc...if you have a leaky line it could affect the air volumn and direction.
  • Thanks for the reply. It's very helpful. That leaky vacuum line on the HVAC system was effecting directional air flow (i.e. flow would not change from defrost to defrost/feet when the dial was changed).

    How can the oil cooler lines hurt an engine? Is it just because coolant leaks or is there any other problems that may arise?

    Thanks again!

  • ramped1ramped1 Posts: 159
    I believe GM had a TSB (technical service bulletin) on the oil cooler lines a couple of years ago. As I recall, I believe the lines and fittings were replaced on the vehicles affected. I'm not sure if it covered your problem, and I'm also not sure whether the '99 model year was included. You may want to call the GM customer service line or check with a local dealer.
  • wilfj1wilfj1 Posts: 52
    I found a posting on the net as to the procedure to reset the code. It sounds like a no brainer but my buddy said be careful you may just mess up the computer memory and end up with a big service bill. Has anyone tried to re program their remotes , with what results.?
  • wilfj1wilfj1 Posts: 52
    did they make a 2000 lumina? I thought the last one was in 99. The Impala came out in 2000. small point. Blazer, Jimmy, for the value you can't go wrong. Did you buy it?
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