Here is an interesting issue that may be affecting many people. The question is when you read a vehicle's trouble codes how accurate are the codes with regards to what the codes are actually telling you?
We recently had a Dodge Caravan with an ABS light on. We read the ABS codes and the ABS module gave us 5 codes. It told us all 4 ABS wheel sensors were bad and that we had a "low voltage" situation. Obviously it is not possible that all 4 sensors went bad at the same time and so we figured some type of low voltage situation was causing the problem. We started by looking at the wiring and eventually we replace the ABS module. The light initially went out but it immediately came back on during a road test. Out of desperation we decided to test the individual sensors and found that one was bad and we replaced it. After that the ABS light finally went out for good.
If all that was wrong was the one bad wheel sensor why didn't the ABS module throw just one code telling us that? What it gave us, the five codes telling us all the sensors were bad and "low voltage", misled us and steered us completely in the wrong direction. We replace a perfectly good and very expensive ABS module as a result. How common is this type of problem? It raises the question of how much trust can you really give to the trouble codes that these vehicle manufacturers are giving us?