The Neighborhood Mechanic: Cracking codes
I know that car repairs are expensive. Cars are complicated. Case in point. A Lincoln Town Car comes in for service. The problem is the interior lights won't go off. I thought I would let you into my world for a moment. Here's just part of the self test straight from the manual. “Connect the NGS tester to the DLC located below the instrument panel. Using the NGS tester perform DATA LINK DIAGNOSTIC TEST. If NGS tester displays CKT914, CKT915 or CKT70 = ALL ECUS NO RESP / NOT EQUIP, see appropriate MODULE COMMUNICATIONS NETWORK article to diagnosis network concern. If NGS tester displays No/ NOT EQUIP for Driver Door Module (DDM) , perform TEST B: NO COMMUNICATIONS WITH DDM under SYSTEMS TEST. If NGS tester displays NO RESP/NOT EQUIP for Lighting Control Module (LCM) perform TEST A: NO COMMUNICATIONS WITH LCM under SYSTEM TEST.”
That's only one paragraph in an article several pages long. To top it off the tech or shop has to go and buy the tester (worth several thousand dollars). Complicated cars require complicated solutions. By the way the repair turned out to be a shorted switch.
Q. I had to stop at my dealer because the check engine light winked on and wouldn't go out. They explained that they would have to connect their computer to the car and read the car's memory. After a few minutes the verdict was that the light set because my gas cap was loose. To my horror they handed me a bill for 65 dollars. For a loose gas cap? Was I ripped off?
A. No you were not “ripped off.” In fact the shop was actually quite fair. In order to read the car's memory the tech will connect a diagnostic scan tool to the vehicle's data link. Once the codes (failure records) have been downloaded the tech will have to interpret the failure and diagnose the cause. Failure codes are recoded as groups of letters and numbers. Once decoded, the codes lead the tech to a series of tests he must perform. In your case it was a loose cap. Most shops charge an hour for this service.
That's only one paragraph in an article several pages long. To top it off the tech or shop has to go and buy the tester (worth several thousand dollars). Complicated cars require complicated solutions. By the way the repair turned out to be a shorted switch.
Q. I had to stop at my dealer because the check engine light winked on and wouldn't go out. They explained that they would have to connect their computer to the car and read the car's memory. After a few minutes the verdict was that the light set because my gas cap was loose. To my horror they handed me a bill for 65 dollars. For a loose gas cap? Was I ripped off?
A. No you were not “ripped off.” In fact the shop was actually quite fair. In order to read the car's memory the tech will connect a diagnostic scan tool to the vehicle's data link. Once the codes (failure records) have been downloaded the tech will have to interpret the failure and diagnose the cause. Failure codes are recoded as groups of letters and numbers. Once decoded, the codes lead the tech to a series of tests he must perform. In your case it was a loose cap. Most shops charge an hour for this service.
