Need electrical help! Code P1637
Le Mans Master
Joined: Feb 2012
Posts: 6,644
Likes: 479
From: OK
2000 coupe here with same code/dic "service engine soon" Intermittent. problem started a week ago, checked connections & upon looking at starter solenoid connections I noticed it wiggled allot but nut was on tight . I squeezed my arm into small accessible area after disconnecting spark plug wire (# 6) & I reached down to the bolt coming out of solenoid, grabbed by hand to feel & the plastic surrounding it disintegrated & bolt with wires attached comes out of solenoid altogether. So I found my problem. Now I have unstart able car. It also has Long tube headers so its a PITA to get to. I guess I need a new starter solenoid. Does the solenoid separate or do I need an entire unit? This sucks BTW. But its better than getting stuck on the road somewhere.
Melting Slicks
Joined: May 2000
Posts: 2,305
Likes: 5
From: Orlando,Fl,USA
True I will look for a new starter & be done with it.
Melting Slicks
Joined: Feb 2014
Posts: 2,725
Likes: 149
From: chicago area IL.
2000 coupe here with same code/dic "service engine soon" Intermittent. problem started a week ago, checked connections & upon looking at starter solenoid connections I noticed it wiggled allot but nut was on tight . I squeezed my arm into small accessible area after disconnecting spark plug wire (# 6) & I reached down to the bolt coming out of solenoid, grabbed by hand to feel & the plastic surrounding it disintegrated & bolt with wires attached comes out of solenoid altogether. So I found my problem. Now I have unstart able car. It also has Long tube headers so its a PITA to get to. I guess I need a new starter solenoid. Does the solenoid separate or do I need an entire unit? This sucks BTW. But its better than getting stuck on the road somewhere.
I have the old style kooks that go in from the top its a PITA to remove them
Melting Slicks
Joined: May 2000
Posts: 2,305
Likes: 5
From: Orlando,Fl,USA
Long tube Belanger headers with stage 8 lock bolts. It looks like it may be possible to squeeze out the starter but not sure until under car.
Melting Slicks
Joined: May 2000
Posts: 2,305
Likes: 5
From: Orlando,Fl,USA
I got the sucker out. Wasn't as bad as I thought. Jacked up 12" off ground & dropped front wheels on some steel ramps I had, plenty enough room to get under there Got the header off & 3 bolt flange connection without any difficulty. I pulled out the 2 bolts & removed wires, bingo, that was it. Now waiting for new starter in mail. 1 week delivery time. I spent about 3 hrs removing & probably need 4hrs to get it back in. Now to lick my wounds & take a boatload of ibuprophen until next time.
Melting Slicks
Joined: Feb 2014
Posts: 2,725
Likes: 149
From: chicago area IL.
I got the sucker out. Wasn't as bad as I thought. Jacked up 12" off ground & dropped front wheels on some steel ramps I had, plenty enough room to get under there Got the header off & 3 bolt flange connection without any difficulty. I pulled out the 2 bolts & removed wires, bingo, that was it. Now waiting for new starter in mail. 1 week delivery time. I spent about 3 hrs removing & probably need 4hrs to get it back in. Now to lick my wounds & take a boatload of ibuprophen until next time.
I did H/C/I on the 10th still have the scars lol
Melting Slicks
Joined: May 2000
Posts: 2,305
Likes: 5
From: Orlando,Fl,USA
Just put in new starter & started right up. Damn code P1637 still showing up but voltage reads 13.5?? WTF. If a fusible link is bad (I didn't see anything unusual while under there) would car even start? Oh yea minimal scars but some Indian burn marks on arm from squeezing in tight space.
Melting Slicks
Joined: May 2000
Posts: 2,305
Likes: 5
From: Orlando,Fl,USA
I had alternator tested as Good on a bench today so I may need to look at those fusible links one more time. Volts show 13-13.3 when driving but drop to 12.5- 12.8 when A/c is on & lights on. If I bump down the blower to low volts will climb up a bit.
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Tech Contributor
Joined: Dec 1999
Posts: 32,910
Likes: 2,402
From: Anthony TX
CI 6,7,8,9,11 Vet
St. Jude Donor '08
If its the IPC volt meter or digital DIC reading,,, you are NOT seeing TRUE battery voltage.
You are seeing the voltage reading being supplied buy the "IGNITION SWITCH" which is way different than the voltage read directly off the battery or BaTT terninal on the alternator.
The ignition switch is fed directly off the battery buss BUT,,, the contacts inside the ignition switch can get dirty corroded burnt and will cause a voltage loss (as seen on that IPC meter).
Test the voltage out of the Cigar lighter or directly on the Battery terminals for a true picture of what the charging system is doing.
You will need a good DC Volt/OHM/AMP meter if you own a C5!
6th Gear
Joined: May 2015
Posts: 6
Likes: 0
Only reason i ask is because i had a similar issue on my Pontiac G8. I purchased an aftermarket alternator through Amazon that was brand new, appeared to work and charge properly but would still throw faults. Sent it back for an exchange, and the same thing happened with the replacement. I wasn't until i spend the cash on an OEM unit from the dealership for it to work properly. You can find a thread to reference here http://www.g8board.com/forums/showth...ght=alternator
Last edited by G8One2; Jun 5, 2015 at 12:41 AM.
Melting Slicks
Joined: May 2000
Posts: 2,305
Likes: 5
From: Orlando,Fl,USA
Bill Curlee : Yes I was using the dash gauge & DIC readings. They were bouncing between 13.3 to 12 but know always in the 11's. I ran some readings with a hand held meter & got these readings. With ignition switch off
S pin 7.8-8.1V
F pin 0
L pin 0.1v
With switch in on position:
S pin 7.6-8.0
F pin 0.1v
L pin 9.75 v
Battery shows 11.8V when running meter from Pos to Neg post.
I ran a heavy gauge wire from pos battery post to alt battery & got the same 11.8 v read.
Stroker 87: No I still have the original Alternator.
S pin 7.8-8.1V
F pin 0
L pin 0.1v
With switch in on position:
S pin 7.6-8.0
F pin 0.1v
L pin 9.75 v
Battery shows 11.8V when running meter from Pos to Neg post.
I ran a heavy gauge wire from pos battery post to alt battery & got the same 11.8 v read.
Stroker 87: No I still have the original Alternator.
Melting Slicks
Joined: May 2000
Posts: 2,305
Likes: 5
From: Orlando,Fl,USA
BUT !!!! I fixed the sucka. it was the wire connection off the starter solenoid. I didn't catch it last time. Right where the wire connects to the ring it was loose & only hanging on by a thread. It broke off upon inspection. It would be the D wire, ( thick red wire with fusible link), not the larger battery one. I also replaced the other small wire while I was there. It now runs in charging mode & code is history) Thanks for all the help
Tech Contributor
Joined: Dec 1999
Posts: 32,910
Likes: 2,402
From: Anthony TX
CI 6,7,8,9,11 Vet
St. Jude Donor '08
Used a multi meter for readings.
BUT !!!! I fixed the sucka. it was the wire connection off the starter solenoid. I didn't catch it last time. Right where the wire connects to the ring it was loose & only hanging on by a thread. It broke off upon inspection. It would be the D wire, ( thick red wire with fusible link), not the larger battery one. I also replaced the other small wire while I was there. It now runs in charging mode & code is history) Thanks for all the help
BUT !!!! I fixed the sucka. it was the wire connection off the starter solenoid. I didn't catch it last time. Right where the wire connects to the ring it was loose & only hanging on by a thread. It broke off upon inspection. It would be the D wire, ( thick red wire with fusible link), not the larger battery one. I also replaced the other small wire while I was there. It now runs in charging mode & code is history) Thanks for all the help
Good job! Now,,, Drive it like you stole it!!
Bill
Melting Slicks
Joined: Sep 2007
Posts: 2,138
Likes: 139
From: Port St Lucie Florida
I have been getting this code P1637 H as well, I took off the passenger side header and went to the solinoid on the starter. I did notice that the main large bolt, when I tried to loosen it the whole solinoid turn slightly, not the actual bolt but the whole solinoid , could this be the problem, the terminals at the alt are tight along with the grnd wires, I checked. Hope bill can advise this.
. Are you sure it wasn't the nut along with the wires turning??
Either way, that shouldn't be happening.
Melting Slicks
Joined: Sep 2007
Posts: 2,138
Likes: 139
From: Port St Lucie Florida
Its weird because on the DIC I am getting code p1637 in history not current, sometimes it comes on sometimes not. My voltage seems ok on the DIC initial start up 14.2 then gradually going to 13.5 volts.
Last edited by corvet786c; Feb 11, 2016 at 02:37 PM.
