P0335 - good sensor and wiring; next probable cause?

[swathdiver]

Did you know that the computer controls the alternator's charging of the battery Al? It tells the alternator to put on a heavier charge after a cold start and then cuts back or off if the battery is charged to wherever it wants it at. There are detailed explanations on it but I keep forgetting the terms!

In Florida, we've had very few batteries last more than two years no matter the rating/warranty. I can count them on one hand and they were AC Delco. But you've said it has passed 2 out of 3 tests. Either its acting up and that space cadet caught it or it's just fine.

 

[baskervi]

1. Ignition OFF, disconnect the harness connector at the CKP sensor.
2. Test for less than 1 ohm of resistance between the CKP low reference circuit terminal B and ground.
 If greater than the specified value, test the low reference circuit for an open/high resistance. If the
circuit tests normal, replace the ECM.

==> I've not done this but will do it tonight. ==> Just did it, and I got 0.2 ohms.

5. Ignition OFF, connect a fused jumper wire to the CKP signal circuit terminal A.
6. Ignition ON, momentarily touch the other end of the fused jumper wire to the battery negative post. The CKP Active counter should increment.
 If the CKP Active counter increments, test or replace the CKP sensor.
 If the CKP Active counter does not increment, replace the ECM.

==> I have an Ancel AD310 scanner, and it doesn't read the CKP active counter. I do have RPM, and that reads OK - from what I've read, that uses the CKP sensor. Autozone has a loaner code reader for around $250, so I can check that out for a bit.

 

[baskervi]

I just saw your comments about the battery. I didn't realize the computer controlled the alternator - I expected some electronic parts that controlled the charger, but not this computer.

Maybe this is a separate question, but what's your thought about purchasing a used computer off of eBay. I found someone who stated he can program it for our VIN? Thanks

 

[swathdiver]

I just saw your comments about the battery. I didn't realize the computer controlled the alternator - I expected some electronic parts that controlled the charger, but not this computer.

Maybe this is a separate question, but what's your thought about purchasing a used computer off of eBay. I found someone who stated he can program it for our VIN? Thanks

It's called Electric Power Management. You can find charts on the internet that shows how it works in certain situations.

If the price is right and the person has good feedback then I would deem it a trustworthy venture.

I forgot to mention something that you might find helpful Al, it's AllDataDIY. You can buy a subscription for your truck and have access to the troubleshooting guides, TSBs, codes, the shop manual, just about everything you need information wise to work on these things. I also bought a DVD from a guy on ebay (SeriousCTBuyer) that had the shop manual in pdf format. It's redundant but I like to switch formats for this or that. He also does downloads.

 

[baskervi]

This is great information. It'll take me a week or so to get everything together, but I'll post back as soon as I can and update the status. Thanks a million.