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Error codes on OBD2 for a '94

Cruise

Active member
Joined
Jan 24, 2002
Messages
38
Location
Barrie, Ontario, Canada
Corvette
1994 coupe
1994 LT1

I need some help deciphering what these error codes mean.
I have a 16 pin DLC and I grounded the #4 and 12 pin, that was recommended for me to do.

The error codes that came up, were as follows:
1 H32
1 H34
1 H36
1 H38
4 H22
9 H64

Can anyone help?
 

compyelc4

Well-known member
Joined
May 1, 2002
Messages
607
Location
Dayton, Ohio
Corvette
'95 LT1 Coupe, Comp Yell; C6 Roadster, Vel Yell
Cruise,

I hope to learn something from this thread. I hope one of us can help you. Where did you get the info to short those particular 2 pins. Actually I am quite surprised to hear that you have a 16-pin in your '94. I could have sworn that they started that crap with the '95. Live and learn! You can just about bet that you do not have an OBDII compliant ECM. Your system should be set up for the OBDI. Anyway I can find no reference to those code types. 16-pins should read the same code types as the 8-pin, which I thought you should have.

Looking at your connector from top to bottom and left to right, which of your sockets actually have pins in them?
 

compyelc4

Well-known member
Joined
May 1, 2002
Messages
607
Location
Dayton, Ohio
Corvette
'95 LT1 Coupe, Comp Yell; C6 Roadster, Vel Yell
To continue, what method did you use to get the alpha-numeric codes? For instance, when shorting 9-pin terminals A and B on OBDI compliant systems the check engine light winks the codes. What the heck did your dash flash at you to get the alpha-numberic characters?

I have a Tech II and have not run across codes like that.

Ted
 

Rabbit

Well-known member
Joined
Dec 19, 2001
Messages
956
Location
sonoma ca usa
Corvette
2004 C5 coupe, MSGM & 2014 Cad SRX Crystal red
I think the 16 pin DLC started in 94. The 95's are OBD I with some OBD II parameters for compliance in 96.

This site will give you some good info.

http:
//www.c4vettes.com/indepth_launch.htm:J :J :J :J :)
 

Rabbit

Well-known member
Joined
Dec 19, 2001
Messages
956
Location
sonoma ca usa
Corvette
2004 C5 coupe, MSGM & 2014 Cad SRX Crystal red
I screwed something up here!


Try this................................

Click here: C4 Corvette In Depth Information - www.c4vettes.com :duh
 

Cruise

Active member
Joined
Jan 24, 2002
Messages
38
Location
Barrie, Ontario, Canada
Corvette
1994 coupe
I asked Gordon Killebrew about the issues that I was having and
he mentioned that it might be related to the Opti spark.
( ASR not working, passing gear not engaging, erratic idling )

He then told me to join the 4 pin and 12 pin, to get my error codes.

The pin connector that I have has 16 locations, but only 10 of them have pins inside.

Looking down at the connectors:

o x x X x x o x Top row
x o o X o x o x Bottom row

The 2 capitol X's are the number 4 pin on the top and the number 12 pin on the bottom row. The smaller x's are the other pins.

After I disconnected my battery after the first error codes, I reconnected the battery and drove the car for about 100 miles on Friday.

The error codes that I now have read:

1 C12
4 H22
9 H64

Can anyone help?
 

Hib Halverson

Technical Writer for Internet & Print Media
Joined
Jan 10, 2001
Messages
13,453
Location
CenCoast CA
Corvette
71 04 12 19
First, some history...
The LT1 engine for MY94 was in the "first" part of GM's so-called "early roll-out" of OBD2 emissions controls. There were a few other GM platforms for MY94 that were also involved.

In 1994, the engine controls had partial OBD2 capibility in that some of the sensors and actuators were present along with some of the PCM programming. In MY94 any OBD2 DTC that occured was stored in memory but did not turn on the MIL. Back then, dealer service depts. were instructed to check any early roll-out car for OBD2 codes as a method of gathering information on how the system worked in the field. This gained GM some very valuable information in preparation for the official implementation of OBD2 in MY96

You cannot read OBD2 codes unless you have a Vetronix TECH1A, TECH2 or Mastertech.

The codes listed in this thread are not OBD2 codes.

You did the right thing by killing power to clear codes then road testing for 100 miles.

1 C12 means you have no fault codes stored for the CCM

4 H22 is the IP display version of PCM DTC22, a fault in the throttle position sensor (TPS). It's a history code which means it was not present when you read the ECM memory. That may be because you did that with the engine off. It is not indicative that the problem has gone away.

9 H64 is the IP display version of ABS/ASR DTC64 which is a TPS fault. Again, this is a history code that was not present when you took data.

Both of these DTCs require a TECH1 or equiv. scan tester and a factory service manual for the DIY to solve. Additionally, ASR DTC64 may require the Kent-Moore J39700 "Universal Breakout Box". If you have access that that equipment and are a DIY experienced in diagnostic work, you can fix the problem yourself. If you are going to use the DIY diagnostic approach, I suggest you use the scan tester to solve DTC22 first, clear codes, then road test. It is possible, if you fix DTC22, that may also solve the other code.

If you're not a DIY, you need a service facility experienced in GM diagnostics.
 

vigman

Motor head!!!!
Joined
Feb 13, 2001
Messages
3,471
Location
Valencia, CA,USA
Corvette
88 Convert ( SOLD ) /1973 coupe 4 speed/1964 Vert!
A thought

Are these codes coming up on the dash in the speedo window?


In that year... (I have to whip the book out )

The H means HISTORY

And C means CURRENT

Vig!
 

compyelc4

Well-known member
Joined
May 1, 2002
Messages
607
Location
Dayton, Ohio
Corvette
'95 LT1 Coupe, Comp Yell; C6 Roadster, Vel Yell
Cruise-

Where are you seeing those codes? On the dash? Are the alpha characters present too?
 

compyelc4

Well-known member
Joined
May 1, 2002
Messages
607
Location
Dayton, Ohio
Corvette
'95 LT1 Coupe, Comp Yell; C6 Roadster, Vel Yell
Cruise et al-

I just found the following entry at a site referenced a few posts back: "For 1994 and later models, you will need to recover the codes using a special procedure involving the speedometer and the odometer as explained in the service manual....."

Does anyone know what the service manual says for a '95 with a 16-pin connector? Does anyone know the procedure? Is this the procedure you followed Cruise?
 

Cruise

Active member
Joined
Jan 24, 2002
Messages
38
Location
Barrie, Ontario, Canada
Corvette
1994 coupe
I appreciate your replies everyone, to my problem.

Answer to the question above:
The codes came up on my dash, at my speedo location.

The codes were in large letters / numbers ( probably 2 inches high ) and the related numbers were smaller, about a half inch high.

It looked like this

1. C12 ( but these characters were a lot larger )

The procedure I used, was from the instructions that Gord Killebrew told me to do.
I counted 4 pin locations from the top left and connected the #4 pin and connect it with the #12 pin.
I then turned my key on and waited for the characters to start flashing.
Once it was done, it stayed on 1.

I do have another question:
Does anyone know of any other website that is similar to this, but for Ford Expeditions?
My wife drives that truck and I am having transmissions troubles with it.
 

Rabbit

Well-known member
Joined
Dec 19, 2001
Messages
956
Location
sonoma ca usa
Corvette
2004 C5 coupe, MSGM & 2014 Cad SRX Crystal red
The procedure Cruise used will work on a 95. The 16 pin connector is numbered left to right, 1 thru 8. The bottom is, left to right 9 thru 16. Ground pins 4 & 12 & then turn ignition "on" but not to start.
After turning the ignition on the CCM will display any DTC"S & the module to which they apply in an automatic display sequence. The CCM is module 1.
The PCM/ECM is module 4. The ABS/TCS EBTCM is module 9. The DERM is module A

During display each DTC is displayed for 3 secs, The end of the DTC list for each module is indicated by "___" being displayed in the speedo..

If you need more please e-mail.

A C-12 indicates no stored DTC"S for the CCM.

When all DTC"S have been displayed the trip monitor will display 1.0 & the speedometer will be blank.

I think....................:hb
 

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