Astro AWD 2002 CODES........ C0310 and P1637

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jd_onair1
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Astro AWD 2002 CODES........ C0310 and P1637

Post by jd_onair1 »

As stated in another post the Service AWD light comes on every once in a while as well as the battery light. First the code the AWD is throwing is C0310 (Motor A/B Circuit Open) From what I have researched this is the Transfer case encoder motor. Any tips or info/ease of fix?

Secondly the battery light comes on and off when ever it seems it needs to. The Voltmeter is perfect, all lights work, not dim, never had a problem other than the light. But me being a perfectionist I don't like it one bit. I was told by a good friend (also mechanic) that his camaro had the same problem and code. He said his did it for 2 years and never had any problems. The code is P1637 (Generator L) anyone know how to fix this?

Thanks for the WONDERFUL/HELPFUL advice in advance!
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MountainManJoe
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Re: Astro AWD 2002 CODES........ C0310 and P1637

Post by MountainManJoe »

Please excuse me if I'm stating the obvious, but I believe in taking a methodical, common sense approach.

Circuit open means theres a discontinuity, or bad connection, so check all the wiring to the transfer case.

The battery light isn't just for the battery. I think it's for the whole charging system. Since you ALSO have a generator error, perhaps your alternator is malfunctioning.

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Re: Astro AWD 2002 CODES........ C0310 and P1637

Post by Cobra »

My service manual doesn't show the P1637 code but i believe it's for the lead that controls the lamp on your dash (which is the plugs on the rear of the alternator) it's goes to your ECM. Give this a read through
http://ww2.justanswer.com/uploads/mcvgr ... -Chart.pdf
Thats the best i was able to find online for the problem i should scan the page of my manual has a test procedure that doesn't use a scan tool just a 5amp fused test lead to trigger the light and digital multimeter to check voltages if you want me to scan it just say teh word
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v8famvan
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Re: Astro AWD 2002 CODES........ C0310 and P1637

Post by v8famvan »

Hi JD,

The C0310 code is not too common of a code for the vans to throw, but it does occur. The most likely cause of this is the transfer case encoder motor as you have already suspected. The simplest way to test this is to simply test the resistance accross the A (Black) & B (Red) terminals to the encoder motor. The resistance should be 0.5 to 35 ohms. If it is not in this range, tap on the encoder motor with a hammer while monitoring the resistance. If tapping on it causes it to go into the correct resistance range, then the encoder motor is no good.

The P1637 code will set if the voltage on the alternator control wire is something other than what the computer expects to see. Usual state for this wire is 10 volts. If there is a connection issue with this circuit - the light may come on. If there is a voltage regulator issue occurring - the light may come on & the alternator may still be charging. This is the most likely cause of your concern, an internally failing alternator.
James from B.C.
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