Howdy, Stranger!

It looks like you're new here. If you want to get involved, click one of these buttons!

Chevy Blazer GMC Jimmy Maintenance and Repair



  • jpmccrjpmccr Posts: 31
    OK Kiddies, heres the poop: 2001 Chevy Blazer LT, 94600 miles, auto, 4WD. I got a Service Engine Soon light (steady not blinking) this morning on the way to work. We have OnStar and they ran the GM Good Wrench Engine Diagnostic for me. It came back with the following info: Good Wrench Code PO155(or P0155) and listed it as Emission Control System Malfunction. What do I need to do since my truck has to be inspected next month. Is this something I can do or is it a Dealer/Mechanic job??? Please help . . . . .
  • repairdogrepairdog Posts: 948
    Easy one gramps:
    P0155 02 Sensor Heater Circuit Malfunction (Bank 2 Sensor 1)
    Replace the front O2 sensor on the passenger side up by the exhaust manifold - look under behind the front tire follow wires to pipe and sensor - check the wires and connector first and make sure they are connected. The rear sensor behind cat is bank 2 sensor 2. One on drivers side is bank 1 sensor 1 (only one). Advance and AutoZ read and erase codes free. About a $55 part. Confirm the code before buying the part.
  • Thanks Dog,
    You wouldn't be able to explain what circuit card and where it may be? Would you?
    I really appreciate your help.
  • jpmccrjpmccr Posts: 31
    Thanks for the information. So I am replacing the one on the front passengers side exhaust manifold. Why so many of these things?? 1 at the converter, and 1 on each side of the manifold? I guess there is a reason but beats me why. I talked to Advance and it is $56.96 (here in NJ anyway). BTW I am not that old just like the sound of it when I typed it in. :P
  • repairdogrepairdog Posts: 948
    As a note 99-01 have the wonderful addition of the secondary air injection pump that blows air into the exhaust manifolds for 1 minute at startup to prefire the cat (pump under radiator and lines and check valves on manifold). The O2 sensors are heated and the PCM monitors each side output vs the cat output and adjusts mixture alone with all other sensor inputs.
  • jpmccrjpmccr Posts: 31
    Again thanks for the information but here is the crazy part of the issue. On my way to pick up the part this morning I notice as I pull out of our development the Service Engine Soon light is out. GONE!!! So I am assuming that since our development has speed bumps, the connection must be loose. So I will check it out. The engine seems to be running fine. Go figure . . . . (I didn't want to spend $57 any way this weekend. TOO cold to be crawling around underneath a truck!) ;)
  • kduffykduffy Posts: 1
  • jtheifjtheif Posts: 4
    I having problems starting my truck in the cold it only happens when it gets cold. If I start it by crossing the starter it will start up (like touch the positive on the negitve nuts on the start it will start right up)other then that once i get it started and go some wherethen park shut off i have a problem restarting it it take several turns of the ignition before it starts back up. the starter i have is brand new maybe 2 months old the starter will click when the key is turned but the flywheel does not move till i cross the starter if anyone has any ideas it would be helpful
    Thanx Frustated Auto Guy :confuse:
  • repairdogrepairdog Posts: 948
    Same as other reply.
  • repairdogrepairdog Posts: 948
    Thats pretty high almost like a pinched off return line. Normal at KOEO is 60-65. The prime circuit is not same as run so check the fuel pump fuses (believe ECM related ones on these older ones) and relays.
  • jax6jax6 Posts: 1
    I have a 97 Blazer (2WD V6 4.3L) that is having the same buzzing behind the glovebox that others have mentioned. When headlights are on, DRL indicator flickers and comes on (sometimes with or without the buzzing noise) and headlights go out. Hitting the brakes, using the turn signals or hazards will make the buzz go in time to the blinking. We replaced the multifunction switch on the steering column and still the noise continues when headlights are turned on. :confuse: Anyone have any other fixes or ideas for this problem? thx.
  • :confuse: :confuse: The heater won't work, I know that the c02 sensor has to be replaced. The heater didn't work about a week ago, we just had a CD player put in and now the heater won't work?! I'm hoping someone knows something. Any suggestions?
  • Actually, a week ago the heater wouldn't work and we played with the knobs for a bit and it kicked on. but now today it won't work at all and there is a weird buzzing sound that you can hear outside of the car but not inside. I wonder if that's something seperate or related?
  • repairdogrepairdog Posts: 948
    Headlight relay chatter possibly. Think its behind the glove box on 97. Also the known problem ignition switch - actually the connector and wiring).
  • repairdogrepairdog Posts: 948
    Air in/clogged heater core will cause a strange sound in the core thats behind the dash pass side. Dex cool needs to be flushed 3/36 do not believe the GM 5/100 crap. If not done in the last 2-3 years get it flushed. If has been done buy 3' of 5/8 and 3/4 heater hose and remove the hoses at the firewall (cover dist so it stays dry) and flush the core with a garden hose and that may do it.
  • I've got the 4wd, so looks really tight to get to block side connection. Using basic tools, will you recommend way to lift engine 1" as you mentioned? Do you need to loosen engine mounts?
  • repairdogrepairdog Posts: 948
    Many people just use a block of wood under the oil pan and a floor jack off set to the drivers side, but the danger is cracking the rubber engine mount. After positioning the wood/jack, you access thru the drivers side wheel well flap, you can remove the long bolt that holds the mount to the frame and then you jack the mount lifts - but access is a pain. Same for that rear bolt on the line to the block which requires access from the front with an 18-24" extension. Then do not forget the little 3/4 inch long bolt holding the lines to the front edge of the block - again a pain so you have to find best access angle for small socket (think I used 1/4" drive racket on that one and all sockets are metric). Take your time.
  • I have a 99 Jimmy. Under normal acceleration it surges up and down until I'm at cruising speed. It seems to run ok until I step on the pedal and then it hesitates before speeding up.The fuel filter has been changed.If I put the pedal to the floor starting up it seems to stop the problem most of the time.
  • repairdogrepairdog Posts: 948
    This could be anything. What mileage and what have you done to it? Any SES codes? By 100k time for cap/rotor/plugs.
  • According to my mechanic the only code coming up relates to the 4wd.He said he's never seen this problem before. On another forum there was a reference to the LEGR valve getting a carbon buildup.It has 95,000 miles. Beside plugs and possibly plug wires what should I replace? The air filter was changed about 8,000 miles ago.
  • dep24dep24 Posts: 1
    This is the ignition. Same thing happened on my 97. I had to get it done at the dealer because by the time you mess around with keys and stuff it ends up cheaper at the dealer. Still not cheap.
  • jim102jim102 Posts: 5
    Thanks for posting this! I have the same problem. Any other info you may have, or pics would be greatly appreciated!
  • jim102jim102 Posts: 5
    I have a 99 gmc jimmy, I have replaced the fuel pump, and the wires. When I start it, it tries to start, then goes dead. I have to get in the back and wiggle the wires connected to the top of the pump, they are tight and in place, but do not seem to be getting a good connection for some reason. The wires were replaced about 6 months ago, but now for some reason have just started doing this. Anyone know what the problem could be?
  • jeff98jeff98 Posts: 1
    my 98 jimmy did the stall thing when it was damp outside and it was my coil wire. good luck
  • 2001 jimmy going crazy while driving check gauges,seat belt,4x4,abs,brake light and battery flash and all gauges go bake and forth except volts and compass flash also but when hit brakes everthing is normal soon as you let go does it again also once when shutting key off everything went blank lights radio etc. what is causing this loose starter wire????? or what help please
  • gibeaugibeau Posts: 2
    1995 Jimmy SLT Is going crazy, started with all dashboard lights and power door and window lights and overhead console lights flicking on and off three times in sync. Then it started flashing over and over(one-two-three-pause.... one-two three-pause...etc)but did not stop when I parked and took my key out. Then I noticed the parking lights and front signal lights where flashing in sync too. Also a beep when I took the keys out. It hasn't stopped and I had to take the battery cables off to stop the battery from draining over night.
    Please Help ....... its a code for something......
  • repairdogrepairdog Posts: 948
    What code #? A vac leak, cap/rotor failing, MAF sensor dirty, fuel pump failing (check pressures), clogged injector, loose wiring, etc. Doubt EGR on newer model but possible. That ignition issue below was 97 specific.
  • repairdogrepairdog Posts: 948
    Bad ground, fuel pump relay, or pump failing again if cheapo one are possible.
  • repairdogrepairdog Posts: 948
    Doubt starter wire cause that primary (small) wire is only powered in stsrt position to get starter to engage. How about the brake light switch up on the pedal having bare wires or internal failure. 2001 had a recall on the flasher/hazard switch and its free replacement and causes only the top mounted brake light to work. Check the battery and the terminals also, as well as alternator (free at most stores).
  • repairdogrepairdog Posts: 948
    Thats not the full digitak dash is it? If so thats the problem, if not is there a security system in the vehicle?
Sign In or Register to comment.