Charging system fault.
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Pro
Joined: Oct 2009
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From: Panama City Beach Florida
Charging system fault.
When I initially start my car it only shows about 11.5 volts, and then after a few moments of driving it kicks back up to above 13V. However it takes so long to do that , that it throws the engine code p1637 and says service vehicle soon. The car is a 04 z06 and has 38k miles on it.
What the hell?
What the hell?
Tech Contributor
Joined: Jan 2007
Posts: 19,347
Likes: 1,124
From: Dyer, IN
When I initially start my car it only shows about 11.5 volts, and then after a few moments of driving it kicks back up to above 13V. However it takes so long to do that , that it throws the engine code p1637 and says service vehicle soon. The car is a 04 z06 and has 38k miles on it.
What the hell?
What the hell?
Drifting
Joined: May 2008
Posts: 1,517
Likes: 319
From: Hewitt TX
Mine does the exact same thing at start up. I have been unable to find the problem because I have not had any time to pull the right side header to inspect the starter solenoid. Starter solenoid is where I would start the inspection. Good luck to ya!
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Pro
Joined: Oct 2009
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From: Panama City Beach Florida
I just ran a jumper cable from pos battery terminal to post on the alternator and there was no change in my problem... if there was an issue at the starter where it all connects together, this test would have had improved results. Am I not correct?
Drifting
Joined: May 2008
Posts: 1,517
Likes: 319
From: Hewitt TX
I believe you are correct because my issue goes away with the jumper installed. Hopefully Bill Curlee will chime in on this to help you out!
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Thread Starter
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Joined: Oct 2009
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From: Panama City Beach Florida
Guys, I still cannot figure this out. When I ran a jumper cable from pos battery terminal to the post on the alternator (to over ride the starter solenoid) the problem did NOT go away. I had my battery load tested. and it is fine. My connections at the posts on battery and alternator are snug.
The problem is strange. When I first start the car(cold start) it reads 14.0-14.1 volts, but after I drive around it drops to 13.4ish... If I turn the car off and then on again when its hot the alternator shows it only puts out 11-12 volts and then a few moments later boosts up to 13.-4ish again. I have the code p1637... could this simply be my alternator going bad. or am I missing something? I would hate to go buy another one if mine is not bad.
The problem is strange. When I first start the car(cold start) it reads 14.0-14.1 volts, but after I drive around it drops to 13.4ish... If I turn the car off and then on again when its hot the alternator shows it only puts out 11-12 volts and then a few moments later boosts up to 13.-4ish again. I have the code p1637... could this simply be my alternator going bad. or am I missing something? I would hate to go buy another one if mine is not bad.
Tech Contributor
Joined: Jan 2007
Posts: 19,347
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From: Dyer, IN
Thread Starter
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Joined: Oct 2009
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From: Panama City Beach Florida
battery voltage yeah hahaah I missed that. 3 hours of sleep here. Yeah. I tested what I thought was pin D and got .16 volts, but turns out that in fact was not pin d. So if my pin D checks out, and over riding my starter solenoid doesnt resolve my issue, its gotta be that my alt is bad huh?
Tech Contributor
Joined: Jan 2007
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From: Dyer, IN
Possibly, but I would want to isolate it. Have you tested the "turn on signal" from the PCM? I'm just wondering if the voltage you see (wherever you are reading it) is battery voltage on start up, before the field voltage turns on the alternator. In any case, I would verify you have 5 volts at pin B on startup.
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Joined: Oct 2009
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From: Panama City Beach Florida
going to my shop to hook up the voltmeter and test this stuff. Ill look for battery voltage at pin D with the car on or off? I will also be looking for 5 volts at pin B on startup..