2000 Isuzu Rodeo

Well I have a little twist to the gas gauge/light promblems currently listed. I am working on a 2000 Rodeo for a friend (I do quite abit of auto repair on the side). The vehicle has a CEL on testing indicates the code is 1627 (PCM A/D Conversion Failure). I think A/D means analog/digital. I can reset the code. However, within 10 seconds the code reactivates. At the same time the code reactivates, the gas gauge begins a slow sweeping motion full to empty and back. Additionally, the low fuel level light blinks continuously at the same time the trouble code activates. Thinking the fuel tank sending unit was creating the problem, I cut the signal wire from the sending unit to the PCM and reset the trouble code. Ten seconds later the code reactivates and the fuel gauge and light react as mentioned above. I obtained another PCM from a salvage yard (yes I know this is risky) and still the same thing happens. I have checked and pulled fuses, disconnected sensors, etc. and reset/clear the code and still it reactivates. Anyone have any ideas/suggestions??
One more thing, the horn is shorted (horn stays on all the time). Determined the problem to be in the horn relay, except I couldn't find it. Finally, discovered it is integrated as apart of the Alarm module behind and to the passenger side of the grove box. Only will cost approx $200 to replace the module according to a local dealership (amazing a regular horn relay costs about $5-7). Just a little info in case someone is interested.

Well I have a little twist to the gas gauge/light promblems currently listed. I am working on a 2000 Rodeo for a friend (I do quite abit of auto repair on the side). The vehicle has a CEL on testing indicates the code is 1627 (PCM A/D Conversion Failure). I think A/D means analog/digital. I can reset the code. However, within 10 seconds the code reactivates. At the same time the code reactivates, the gas gauge begins a slow sweeping motion full to empty and back. Additionally, the low fuel level light blinks continuously at the same time the trouble code activates. Thinking the fuel tank sending unit was creating the problem, I cut the signal wire from the sending unit to the PCM and reset the trouble code. Ten seconds later the code reactivates and the fuel gauge and light react as mentioned above. I obtained another PCM from a salvage yard (yes I know this is risky) and still the same thing happens. I have checked and pulled fuses, disconnected sensors, etc. and reset/clear the code and still it reactivates. Anyone have any ideas/suggestions??
One more thing, the horn is shorted (horn stays on all the time). Determined the problem to be in the horn relay, except I couldn't find it. Finally, discovered it is integrated as apart of the Alarm module behind and to the passenger side of the grove box. Only will cost approx $200 to replace the module according to a local dealership (amazing a regular horn relay costs about $5-7). Just a little info in case someone is interested. I am having the same trouble code problem with my 99 rodeo, if you figure it out please post, i will do the same. Thanks

I don't have experience in those, but I can tell you that a reputable salvage yard will give you a warranty (some are lifetime) for their parts- even for computers.
See if you can find a service/troubleshooting manual for that year and see if they have a flow chart.

Also look for vehicle specific forums on the web that might specialize in them.


Jason