2003 GMC Jimmy. v6 Vortec 4.3 liters. Question: I've owned the Jimmy for about three years, haven't had to do a tune up yet. I would like to know what i need to get it done. I have no major complaints to report. Being used to owning old vehicles that needed tuned at least once a year, kinda got spoiled with this GMC truck.

 

Answer: Nothing extra special to do on this truck than any other vehicle. A major tune up would require replacing the air filter, spark plugs, spark plug wires, distributor cap and rotor, fuel filter, PCV valve, inspect the ignition coil, check all fluid levels and condition. If over 100k miles, suggest getting the transmission fluid and filter changed, coolant flushed and brakes inspected, as well as front end and steering components. Inspect the belt for cracking and wear, check the tires and battery and inspect for any leaks.


Scanner Won"t Read Codes

1996 gmc jimmy 4x4. 4.3 Vortec. Question: I am a truck mechanic but this has stumped me i hook up to my obd2 scanner the scanner powers up ok truck runs fine starts fine but obd says unable to find system engine light on airbag light on .

 

Answer: You have a Class 2 Serial Data Line problem. The power and ground work ok at the diagnostic port, but you've lost the serial data signal where the scanner can 'talk' to the vehicle. It can't find anything because it's getting no response on the data line. If you could pull codes, you'd probably find a few U1000 codes with loss of communication to whatever module can't connect with the others. This problem could be due to a broken wire, a bad connection, or even a bad module such as the PCM or SDM (airbag module). Since you have a check engine light and an airbag light, I'd start looking in that direction first. You can try disconnecting modules one at a time to see if the problem goes away and then you'd know what to replace or where your problem area is located.

 


Leave your comments

Post comment as a guest

0

    Comments
    Subscribe To These Comments-----   

    • No comments yet.

    Latest Articles

    Impala Flashing Engine Light

    I have a 2003/2004 impala i was driving it on the high way ...

    Hyundai Tucson 2016 A/C Blows ...

    2016 Hyundai Tucson. A/C worked great, parked the car for a ...

    Chevrolet Blazer Lost Power ...

    2000 blazer 4x4 lost power to drivetrain going down the ...

    Dodge Durango Timing Chain ...

    My 03 Dodge Durango 4.7L engine was blowing white smoke ...

    2002 Chevy Blazer Keeps ...

    My 2002 blazer keeps dying on me when I am driving, and ...

    How Things Work

    Windshield Wiper System Operation

    The windshield wiper motor module is part of the windshield wiper motor cover and controls wiper motor operation. The accessory voltage supply circuit to the windshield wiper motor assembly is used to operate the wiper motor in all modes. The windshield wiper motor is a 2 speed motor and is operated at low speed in all modes except HIGH.

    Read more...

    Common Engine Codes

    P0128 Coolant Temp Below Themostat Threshold

    An engine coolant temperature (ECT) sensor monitors the temperature of the coolant. This input is used by the powertrain control module (PCM) for engine control and as an enabling criteria for some diagnostics.

    Read more...