Volts read "sys" not 14.3
Thread Starter
Racer
Joined: Jan 2005
Posts: 418
Likes: 45
From: Houston Texas
Volts read "sys" not 14.3
96 stock LT1 with no mods (electrical or otherwise). Garage Queen hasn't been driven in a month. Key-On/Engine-Off initial reading before startup was 12.1, and it started right up and ran fine. Volts immediately went to 14.6 +/- (Alternator charging).
After 20 minutes of driving, I noticed the volt reading settled down to 14.3, but would intermittently switch between 14.3 and "sys". Nothing in the handbook I could find. Before I drag out the Helm and spend an afternoon reading thru that, can anybody shed some light on this issue?
In keeping with another recent post, THANKS in advance! All help and positive comments are always appreciated, just not always acknowledged in the excitement of solving our various problems.
After 20 minutes of driving, I noticed the volt reading settled down to 14.3, but would intermittently switch between 14.3 and "sys". Nothing in the handbook I could find. Before I drag out the Helm and spend an afternoon reading thru that, can anybody shed some light on this issue?
In keeping with another recent post, THANKS in advance! All help and positive comments are always appreciated, just not always acknowledged in the excitement of solving our various problems.
Thread Starter
Racer
Joined: Jan 2005
Posts: 418
Likes: 45
From: Houston Texas
No codes, but my reader is giving me an "E". I pulled the TPS off just to check the reader, and it gave me the proper code. Reinstalled the TPS and again got the "E". I have misplaced my book that came with the code reader, so I can't look up what "E" is supposed to mean. Looks like this is gonna be a "Helm" day.
Thread Starter
Racer
Joined: Jan 2005
Posts: 418
Likes: 45
From: Houston Texas
Originally Posted by bogus
there are two code sources... the PCM and the CCM. You need to pull CCM codes...
Melting Slicks
Joined: May 2004
Posts: 2,524
Likes: 10
From: Lufkin Texas
St. Jude Donor '05-'06
Originally Posted by DMGroh
I'm plugging my reader into the link just under the steering column. I assumed that would give me whatever codes I needed. Is there another place to pull codes? Do I need another type of reader?
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Thread Starter
Racer
Joined: Jan 2005
Posts: 418
Likes: 45
From: Houston Texas
Originally Posted by skateparkdave
Uhh hello! Read my post above. Your dash is a reader. The # will be the module. Example: #1 = ccm Then whatever if any code will follow.
Thread Starter
Racer
Joined: Jan 2005
Posts: 418
Likes: 45
From: Houston Texas
Seems like I wasted money on that code reader and need to put the paperclip back into the tool box!
Here's what I have:
1: H31-H33-H35-H37
9: H64
A: blank (no codes)
1.0: Blank (no codes)
One of my manuals indicates the H3x is the left & right rear wheel sensors (malfunction & continuity)
The H64 is the TPS which I intentionally caused-this should be a non-issue.
Here's what I have:
1: H31-H33-H35-H37
9: H64
A: blank (no codes)
1.0: Blank (no codes)
One of my manuals indicates the H3x is the left & right rear wheel sensors (malfunction & continuity)
The H64 is the TPS which I intentionally caused-this should be a non-issue.
Melting Slicks
Joined: May 2004
Posts: 2,524
Likes: 10
From: Lufkin Texas
St. Jude Donor '05-'06
Ok, now we're getting somewhere.
My notes and code sheets are for my 1990 and they dont show codes 31 and 37 at all. The "H" stands for history. Which means they could be old and now fixed but not cleared. To clear codes just unhook the negative terminal of your battery for 15 seconds and reconnect. Then run the car for a while and check for current codes.
My list shows code 33 to be MAF circuit, then 35 to be IAC circuit.
It shows 64 to be a lean exhaust O2 sensor code but thats for module 1 and not 9 which is ABS/ASR module per list above so I dunno.
Hope this helps.
My notes and code sheets are for my 1990 and they dont show codes 31 and 37 at all. The "H" stands for history. Which means they could be old and now fixed but not cleared. To clear codes just unhook the negative terminal of your battery for 15 seconds and reconnect. Then run the car for a while and check for current codes.
My list shows code 33 to be MAF circuit, then 35 to be IAC circuit.
It shows 64 to be a lean exhaust O2 sensor code but thats for module 1 and not 9 which is ABS/ASR module per list above so I dunno.
Hope this helps.
Last edited by skateparkdave; May 6, 2006 at 03:06 PM.
Racer
Joined: Apr 2005
Posts: 408
Likes: 0
This is from the 96 service manual. A 1 indicates these are stored codes for the ccm.
h31-lcd data circuit shorted to b+ or ccm internal open
h33-data clock shorted to b+ or ccm internal open
h35-data strobe circuit shorted to b+ or ccm internal open
h37-m clock circuit shorted to b+ or ccm internal open
These all point to either a wire in the lcd circuit shorted to a 12 volt power source, the lcd display has an internal problem or the ccm itself is bad.
9 indicates the abs/traction controls system.
h64-throttle position signal malfunction
A indicates the Diagnostic Energy Reserve Module which is part of the airbag system and no codes are set.
The ccm then displays a 1.0 when it has finished.
Every module in the car has its own set of codes, and the ccm can display them, as you've already done, but the codes do not necesarily cross reference to other years and a code 31 for the pcm is not the same as a code 31 for the ccm. Hope this helps.
h31-lcd data circuit shorted to b+ or ccm internal open
h33-data clock shorted to b+ or ccm internal open
h35-data strobe circuit shorted to b+ or ccm internal open
h37-m clock circuit shorted to b+ or ccm internal open
These all point to either a wire in the lcd circuit shorted to a 12 volt power source, the lcd display has an internal problem or the ccm itself is bad.
9 indicates the abs/traction controls system.
h64-throttle position signal malfunction
A indicates the Diagnostic Energy Reserve Module which is part of the airbag system and no codes are set.
The ccm then displays a 1.0 when it has finished.
Every module in the car has its own set of codes, and the ccm can display them, as you've already done, but the codes do not necesarily cross reference to other years and a code 31 for the pcm is not the same as a code 31 for the ccm. Hope this helps.
Last edited by lt4red; May 6, 2006 at 04:13 PM.
Thread Starter
Racer
Joined: Jan 2005
Posts: 418
Likes: 45
From: Houston Texas
The '96 Helm manual (for my '96 car) shows me those LCD codes, but in another section of the manual also shows the same code numbers applying to the rear wheel sensors. The "9.H64" code correctly (I feel) points to the TPS, but that should be a PCM code, not an ABS code ???
So at this point, I don't know if I have a wheel sensor problem or an LCD problem.
Anyway, I cleared the codes per the manual using the trip/odo and holding the eng/met. Now, I only get the C12, which I assume means that all is well. However, this method did not clear the 9.H64. I'll do that by disconnecting the battery terminals. A little preventative maintenance on the terminals is probably needed anyway.
So at this point, I don't know if I have a wheel sensor problem or an LCD problem.
Anyway, I cleared the codes per the manual using the trip/odo and holding the eng/met. Now, I only get the C12, which I assume means that all is well. However, this method did not clear the 9.H64. I'll do that by disconnecting the battery terminals. A little preventative maintenance on the terminals is probably needed anyway.
Racer
Joined: Apr 2005
Posts: 408
Likes: 0
Originally Posted by DMGroh
The '96 Helm manual (for my '96 car) shows me those LCD codes, but in another section of the manual also shows the same code numbers applying to the rear wheel sensors. The "9.H64" code correctly (I feel) points to the TPS, but that should be a PCM code, not an ABS code ???
If these codes were displayed under "9" then yes they would be for the wheel sensors. Remember each system has it's own set of codes. If they are displayed under heading "1" then these are ccm codes.
Thread Starter
Racer
Joined: Jan 2005
Posts: 418
Likes: 45
From: Houston Texas
The 31-37 codes were under the "1." which indicates CCM, thus the LCD/clock/square wave thing(?) described in the manual. I'll disconnect & charge the battery, clean the terminals, and road test tomorrow and report back. Thanks for the help so far.
I thought I had read hundreds of tech issues on this site and the others (GM, LT1, etc), and this is the first I've heard of the paperclip trick working on the 16 pin connector. Does it only work on the Corvette, or any 16pin car?
I thought I had read hundreds of tech issues on this site and the others (GM, LT1, etc), and this is the first I've heard of the paperclip trick working on the 16 pin connector. Does it only work on the Corvette, or any 16pin car?
Melting Slicks
Joined: May 2004
Posts: 2,524
Likes: 10
From: Lufkin Texas
St. Jude Donor '05-'06
Originally Posted by DMGroh
I thought I had read hundreds of tech issues on this site and the others (GM, LT1, etc), and this is the first I've heard of the paperclip trick working on the 16 pin connector. Does it only work on the Corvette, or any 16pin car?
