Fighting Trouble Codes
Q: I have a 2001 Rodeo with P0463 and P1860 codes. Where do I find these parts without paying markup through the dealers?
A: Those numbers are trouble codes stored in the PCM's memory and don't directly refer to parts. It's never a good idea to replace parts without first confirming the failure by means of the recommended diagnostic procedure. Code P0463 was set due to a high-voltage fault in the fuel-level sensor circuit. This may be caused by a bad sensor, the powertrain control module, or a short in the applicable circuit. Code P1860 shows up when there's a problem in the circuit driving the TCC (torque converter clutch) solenoid located in the automatic transmission. Again, it could be a defective TCC solenoid or the PCM, or an open or short to ground in the wiring between the two electronic components. Get it to a qualified shop to accurately diagnose the problems. After that, any parts store worth its salt should tell you if less-expensive aftermarket parts are available, or if you'd be better off with a dealer-only item.
Find the GM Noise
Q: I hope you can give me some peace and quiet. I purchased a 2002 GMC regular-cab Sierra with 30,000 miles on it, and purchased the extended warranty. The cab mounts/bushings/bolts make a clunking noise and scrunching sound when I stop or turn the vehicle into parking spots. I know the previous owner had the same problem. The dealer tried several times to repair the noise. It stays quiet for a couple weeks, but comes back. Can you suggest something for me to try or information I can give the dealer?
A: I haven't found any service information on body or cab-mount noises on 2002 Sierras. There have been clunk noises from the front coil springs corrected by a modified rubber insulator and also rear leaf-spring noises due to broken insulators at the end of the second-stage leaf. You may want to ask the technicians if they've conclusively narrowed down exactly which mount the noise is coming from. If not, they may want to use an electronic listening device to be sure they're focusing on the right area. Perhaps they only temporarily corrected the noise by lubricating the rubber mount as opposed to replacement. Or the noise could actually be emanating from a component near the mount, but not from the mount itself.