Help! 93 corvette no start no crank issue

[John Robinson]

Ok you too lets get something straight here. In response to the op question and posting of the codes he was getting I went to my 93 fsm and indicated in red what the fsm dtc code title was for. Having done that I then went to my archives and posted the dtc diagnostice sheets for the code 41 and 64 along with a copy of were the ground points were located. My objective was to open as many doors as possible of the things that could cause his problem. I sensed that the op was mechnically inclined since he had swapped out parts from a friends car to get the instrument panel to come to life. I feel it is not my place here to tell someone that their problem is only one thing. I can not know that since I am not doing the checking and following the diagnostic procedures as specified in the fsm. I wanted to help the op understand that before he invests in a lot of parts there were other things to eliminate as possible area's of trouble. Now you might want to ask yourselfs why I had all of these codes etc scanned into my computer. Could it be that I have been down this road on my 93 and I am helping the op find his own path to resolving his problem. I appreciate what you both have contributed in the past some of which has been helpful to me. But think about how this forum must look to someone who is new and only posted 4 times. If you must disagree do so in the private message section and not on the op post. I invite the op to contact me privately if I can be of further help.

 

[vigman]

Ok my take on the situation

The OP states
"I have been trying to get it running since I got it."
I borrowed another CCM from a friend out of a 1993 covertible (This will invalidate the stock key VATS/Keypass pellet.. UNLESS you replace chips I believe )
When you turn the key to crank the engine I get a no crank issue from the starter.
If you jump the starter solenoid at the relay to a ground, the starter will engage when the key is in the run position.

So here's the drill.....
1) You need to measure your buddies key pellet to unlock his CCM,and substitute the correct resistive value into the 2 pin connector ( Wht/Blk and PPL/Wht ) that GOES to the wiring harness ,and unplug the connector going to the the pass key going up to the column. (Wht/Blk pin E12 on CCM and PPL/Wht F5 on CCM)

2) On the CCM pin F4 will go LOW ( ground ) when the pass key is correct ( and everything is powered up correctly ).

3) The starter enable relay F4 (CCM) goes to relay pin 2 ( Blk/Yel ) of the coil of the relay.
The HOT relay coil feed, pin 5 (yellow) comes from pin E of the PARK /Neutral switch.

4) Test #1 Verify with a 12 volt test light that RELAY pin 5 goes HI ( or hot ) in only park & neutral.

5) The Vats/Keypass relay ( control side ) pin 1 is yellow (large gauge) and pin 4 Purple (large gauge) goes to the starter solenoid...


So even if you jump the starter relay.. the rest of the CCM will not be happy till the resistor is the proper value...
AND it would be helpful to know how you jumped the relay.....

Additional.. without knowing what other damage has happened to the car, condition of the rest of the electrical system... this will get " interesting..
The CCM connector is the green one
data comes from 1993 shop manual
Pages 8D-14 through 18


Mike

 

[Schrade]

H-72 I agree with Schrade



Again, the type of damage would be helpful finding faults...
In my G... When the owner got into an accident ( hit a building head on.. DUHRRRR ) the shifter ( and switch ) were toast...
He used the shifer & wheel as a brace for impact grip....so if the selector switch is broke... no park neutral signal.. no crank, no fire...
and VATS if you have that will prevent a crank....IF you have that ( a pix of the keys would help here )

Thanks vigman, but he was right, and I made a mistake callling module 9 H64 an O2 sensor circuit.

I can admit when I was wrong.

I DON'T need that character's help doing it.

If the shifter P/N switch is faulty ;how come the OP can crank the engine over if he jumpers the starter enable relay as he stated in his first post ........................?

Does the solenoid jump BY-PASS the ignition switch-to-gear selector circuit??? Let's see the circuit / diagram???

 

[vigman]

This statement gives me pause....

"the starter will engage when the key is in the run position"...

I now know how the circuit is designed to do ( doing a bit of studying ) ... it's now the variables of:
Wrecked car and OP's experience..combined with outside parts...

I would assume, as you did, that the car should crank if the relay is properly jumped in START...
"the starter will engage when the key is in the run position" ( run ) being the ???

Jumping the coil doesn't PROVE the Park Neut switch is 100% functional ( In my mind ) ...
If it were my car... I would confirm the relay closes in park AND neut.. and doesnt in any other selection..
( But I'm paranoid like that )

Oh and.....does everyone agree that the VATS resistor needs to be replaced ( faked out ) to move to the next step?

I'm not 100% sure if changine the EEprom will take the keypass / VATS info along with it....
( And if it were my CCM on loan. I wouldn't want to be silicone swapin' )

Mike

 

[vigman]

Oz you just proved my question

With your schematic, the starter should only engage in start.. not run with the bypass going from to ground from relay pin 2...

1 in 15 hahahah better odds then Vegas....

Ok so I hope the OP reads this and reports back

 

[cowansauto]

If we had an idea of the damage... it might eliminate some of the variables....
Did 93 still have Vats or was it Keypass?

The car was really not damaged that much. Here's a picture of the damaged hood/front bumper area removed.



Thanks for all the replies and suggestions. I'm trying to play catch-up now. With all the response, Im a little overwhelmed on where to start.

1. In reference to "engaging the starter by jumping the starter relay", I did this by grounding pin 30/Black-Yellow wire at the starter relay to the metal dash bracket. When I turned the key over all the way forward to the start position, the starter would engage but I could not get the engine to fire over and run.

2. The CCM was taken out of a 1993 Corvette Convertible parts car at the friend's salvage yard. That car did not have a column in it when I pulled the CCM out. So I take it the VATS values would be different between the two CCM's since its incorporated into the CCM on this model?

I know the value of my key 0.887K Ohms and tried the wire/resistor bypass trick (soldered in resistors to match the OHM's value of the key I have/Attached a connector with the resistors connected to the connector at the column that goes to the VATS module) before & after the CCM change to determine if the key swtich was at fault and got the same results=No Crank

3. With the original CCM installed, I could not get the DTC's to show up at all since the LCD was gone. Even on a friends nice Snap-On tablet, the CCM was not displaying any data to the tablet

 

[Schrade]

If your inflated ego
"You don't know as much as I do. You can't diagnose as good as I can, and you can't communicate as well.....I think you're a horse's ass.."

had let you read what I previously posted it might have saved you getting on your high horse and being abusive?

Old saying

"tis better to appear a fool than open one's mouth and remove all doubt"

If you read my posts carefully, you'll note that I say, "I think ... this, or that".

I think the 64 is O2 sensor out of normal range.

Can't be wrong guessing. What did you offer? Schematic? Welcome even?


And if you listen to politicians, the ONLY thing you hear them [post on the vette forums] is, "He's wrong / His stuff doesn't work"

I still think you're a horse's ass. Or a politician... take your pick.

If someone learns something 'cause I make a mistake, who gets credit? YOU??? Nope, cause you wouldn't have said squat if I hadn't offered it.

 

[Schrade]

The only way the engine will crank is by jumping the relay or the starter posts.

OP - can you draw on the schematic exactly which leads you are jumping, when you say that EITHER of these 2 bypasses gets the engine to crank?


]]]]]]]]]]]]]]]]]]]]]]]]]]]]]]]]]]]]]]]]]]]

The engine would crank over or not?
.....

If you had read OP's posts as critically as you read mine, you would have seen this:

Thanks for the attachments. By looking at the steps, it seems necessary to get the engine cranking first though. The only way the engine will crank is by jumping the relay or the starter posts.


If you wouldnt mind, could you attach the steps for a No Start issue from your 93 service manual?
Here is what I have from All Data DIY (sometimes helpful, sometimes not)!

I missed a couple of points too, but you NEVER see me busting on ANYBODY'S posts here.

I don't think anything more need be said pal...

 

[cowansauto]

Post # 38
When I turned the key the starter would engage but I could not get the engine to fire over and run.
If you know what that means you are a better man than me

With the starter relay grounded, the starter will engage in the start position but the engine will not run. The engine just keeps turning over and over.

im going to check the fuel pressure again in a little bit. Should there be any fuel pressure at all in start or when the starter is engaging in the method above if the Secuirty system is not getting the proper codes (Narrowing down the issues completely)?

i also have a VATS interrogator that I might could borrow to get the resistance the new CCM requires.

 

[Schrade]

With the starter relay grounded, the starter will engage in the start position but the engine will not run. The engine just keeps turning over and over.

im going to check the fuel pressure again in a little bit. Should there be any fuel pressure at all in start or when the starter is engaging in the method above if the Secuirty system is not getting the proper codes (Narrowing down the issues completely)?

i also have a VATS interrogator that I might could borrow to get the resistance the new CCM requires.

Can you post a vid like you did for the first post, of exactly how you're getting the starter to spin the motor?

You get the motor spinning, but is the Ig System on? Is there spark? We don't know what's broken in THAT circuit?

Yes, you should get around 40+ lbs FP, under NORMAL conditions... If you don't, you'll have to test the FP circuit.

I don't have that schematic, but if I post any way to get started on it, someone else will bust on my stuff again, and MAYBE post THAT schematic :eyerole

 

[cowansauto]

I can get the starter to engage by jumping the wires at terminals 87 (large Purple) & 30 ( Large Yellow) together Or by grounding a wire to terminal 85 (black/yellow wire).

UPDATE-
1. Noticed no spark earlier and that the connector to the ignition control module was broken. Replaced module, cleared codes, turned key off, waited 10 sconds and checked the codes again:
#1 C12,---,
#4 ---
#9 H72, ---


2.Cleared codes,

3. Cranked engine grounding black/yellow wire. Engine only cranked again as usual. Checked codes afterwards and the #4 H41 code is back. Is this because of how I was attempting to crank the engine?

#1 C12,---,
#4 H41, ---
#9 ---

DTC 41 =Ignition Control (IC) Circuit (Open Circuit)

 

[Schrade]

It's obvious that you know how to read the schematics - good work there...

So we don't know where the open is in ignition circuit.

And we don't know if you can generate fuel pressure...

I still say that the gear selector switch Mod 9 H-72 could be the starting point. Does the computer look for something that is NOT there? Or does it see something that IS there, but is WRONG???

Someone in particular (won't say who :L ) won't post that, until I say one or the other...

 

[Schrade]

Put me in my place, and solve OP's problem. No more BS, like http://www.corvetteactioncenter.com...rms-up-then-no-fuel-pressure.html#post1112555 , just solve the problem.

Unless you ARE the problem.

And here's YOUR solution (swap Schrade for vetteoz):

 

[cowansauto]

Guys thanks for the help so far. Unfortunately with all the bickering that is going on, this thread has become nearly impossible for me to read without becoming confused. This isnt my first visit to a new forum that I registered at, but it has been one of the worst first time experiences. I do however, understand that this type of behavior does not exemplify the entire board or its members and will continue to use this website.

For my sake, I would appreciate it if the authors edit any comments on this thread that do not offer positive comments or suggestions to the issue with my Corvette and not regarding issues between one another. This would make the post a useful tool for the next reader and certainly give the site a better appearance to those that visit.

-Aaron

 

[KANE]

We have a lot of members who know their stuff. We also have a lot of members who have a lot of pride in what they know. Let's keep the focus on Vette problems.

Back and forth about who knows more of what is quickly draining any value from this thread.


KANE
Corvette Action Center Moderator

 

[vigman]

My take in the 1st step from here

So if the new CCM is from a wrecking yard.. it MIGHT be a good move to change the Eprom but someone else would need to VERIFY if that will take the Vats/Keypass value with it...
( or maybe your CCM has no chip in it.. ) How many miles on the car, what area do you live in, and a front end pix might be helpful ??

Thanks for clarity on how you got it to crank.. makes MORE sence now...

I think finding the correct resistor value would be my next move..
GOOD PLAN=i also have a VATS interrogator that I might could borrow to get the resistance the new CCM requires.
I made my own a while back...I included a resistor table so you could old skool it..
Pick a value.. try it.. ( No start ) disconnect the battery.. wait 5 min re connect the battery repeat till cranks on it's own.

I would do this BEFORE chasing other issues.. once you get the car running ( or at least trying to fire, or at minimum crank W/O magic jumpers at the relay ) the error codes will have more meaning..
As OZ suggests you could do the 30HZ bypass, that would be another work around to the Vats/Keypass issue.

This might be good general info for the resistor values:
http://www.thirdgen.org/vats_passkey_system

Or the 30 Hz magic box:
http://www.bakerelectronix.com/products_vats/

93 has opti spark in it ( that might be a whole other kettle of fish to deal with ) , A spark check might be a good idea at this point at least you might get baby to BURP with some starting fluid...
One step at a time.....


Mike

 

[vetteoz]

So if the new CCM is from a wrecking yard.. it MIGHT be a good move to change the Eprom
but someone else would need to VERIFY if that will take the Vats/Keypass value with it...
( or maybe your CCM has no chip in it.. )

No chip in the CCM , it is just programmed to look for a set fixed resistance value from the key pellet
If you swap a VATS module ( early cars ) or the CCM ( on '90+ cars ) you need the matching key to go with it ( 1 in 15 applies )
The memcal (PROM) in the ECM is programmed to look for the fuel enable signal from the CCM which is generated after the CCM
sees the correct key
VATS on the memcal can be disabled with a custom tune on a new EPROM
VATS Delete Chips

 

[vigman]

Thanks OZ!

I couldn't remember that to save my life~
More clarity =GOOD

 

[Schrade]

Guys thanks for the help so far. Unfortunately with all the bickering that is going on, this thread has become nearly impossible for me to read without becoming confused. This isnt my first visit to a new forum that I registered at, but it has been one of the worst first time experiences. I do however, understand that this type of behavior does not exemplify the entire board or its members and will continue to use this website.

For my sake, I would appreciate it if the authors edit any comments on this thread that do not offer positive comments or suggestions to the issue with my Corvette and not regarding issues between one another. This would make the post a useful tool for the next reader and certainly give the site a better appearance to those that visit.

-Aaron

I apologize cowansauto. And I apologize to the other guy too. It takes a lot to start me to name-calling.,,

And I apologize to the mods / admin too. I'm sure sponsors don't appreciate such on the boards.


sigline edited too - sorry about that...

 

[Crazyace909]

Just a thought about the VATS I remember once that I unlocked my drivers door manually from the passengers side once and when I opened my door and got in and tried to start my vette it wouldnt turn over. Confused I tried several times. I then thought mabye the security system wasnt picking up that I had unlocked my car so I unlocked the drivers door with the key and then tried to start it and it started right up.

Just a thought from my own experience.

But it may not work for all. Worth a shot though..

Larry M

You may have to put your Body Control Module back in though.