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Speedometer reads 0 always.

Ethan

Well-known member
Joined
Jul 14, 2001
Messages
68
Location
Elgin Tx. USA
Corvette
1991 L98 Coupe
Need help just replaced vss sensor and gears in tranny look good .What else could be wrong on a 91 Vette with Lcd spedo display.Always reads 0 no indication of speed is this connected to the lockup converter plug also? Thanks Ethan
 
Do you know how to enter self diag's?

There is a series of button's to press on the DIC panel to enter diag's.

Have you done this?

Any SES light?

Vig!
 
Woof

CCM error polling ( Repost )

I will also add some other clever stuff later to amaze & confuse. ( so check back )


If your ALDL connector looks like this, you can proceed,If not ( more pins than this) STOP!
This is for ODB style 1

F E D C B A
G H J K L M

I think 94 was the first year of ODB 2

But..My Actron scanner states it will check up to a 95.. which I have not done personally

( Made the same mistake with another post )

If your looks like the above..proceed


You can pole the CCM and get ALL the error codes for the CCM system


TURN OFF KEY..FIND ALDL CONNECTOR
(UNDER DASH LOWER THAN YOU KNEE WOULD BE)

To read the CCM

Key Off
Have pen & paper ready
Jump pins a & g in tha ALDL connector paperclip will do (Top left A bottom right G)

turn key on
This will start the Auto diag of the CCM
The numbers where the speedo lives will give you codes eg C 51 or H 51
(the C means current H means History)
and below there will be another number
( eg 1.1, 2.1 etc)
These will tell you the MODULE at fault.

Write this info down
Repeat as needed
To exit
Key off
Remove the jumper

Manual Navigation
At the end of the AUTO Error display it will park you into Manual diagnostics mode.You can have all kinds of fun here.

There are many different MODULES CCM,ECM,ABS, ETC
Each of these modules has TEST?s ( more than one)

Some TEST?s you can input VALUES ( eg from the CCM you can put in a number to test the door locks..and from the number you input you see a result, and you can reverse it so you hit a switch.. the CCM will tell you that it see?s that input..Neat HUH?)

So on the DIC buttons
FUEL info= Previous value
ENG/MET= Next value
GAUGES= Previous test
TRIP ODO=Next test
FUEL RESET=Previous module
TRIP RESET= Next module

Terms
CCM= central control module
ECM= engine control module
ABS= Automatic Braking System



Modules
Display CCM DTC?s = 1.2
Display CCM status= 1.3
Cycle CCM outputs= 1.4
Clear CCM DTC?s= 1.7
Display ECM DTC?s = 4.1
Clear ECM DTC?s-= 4.7
Display ABS/ASR DTC?s = 9.1
Clear ABS/ASR DTC?s = 9.7

Display CCM status
MODE 1.3
Hit TRIP/ODO till 1.3 is selected.
Hit ENG/MET(next test) till your at the test you want to see.
If you overshoot hit FUEL INFO( last test)
This will let you run thru all the inputs the CCM "see?s"
Input ID
01= Pass Key/FUEL
02= English or Metric
03= Door Key Switch
04= Right Door Ajar
05=Left Door Ajar
06= Key in the Ign.
07=Rear Hatch ajar
08=Power locks Unlock
09= Power locks Locked
10=Parking Lights
11=Rear defogger (press the button a few times so see the state change)
12=Seat Belt (drivers only)
13=High Beam (lights need to be on DUH!)
14= Low Oil level sensor

Test CCM outputs
MODE 1.4
Hit TRIP/ODO till 1.4 is selected.
Hit ENG/MET(next test) till your at the test you want to see.
If you overshoot hit FUEL INFO(last test)
This will allow you to make the outputs of the CCM switch on or off
The last digit of the odometer will indicate a 1 for on and a 0 for off
HOW DIGITAL CAN YOU GET!


Outputs
01= Change oil light
02= Check gauges light
03= Fasten seatbelt light
04= Security light
05= Hi Beam
06= Chime slow
07= Chime fast
08= LCD Blank
09= Rear window defog
10= interior lights
11= Low oil light
12= Starter Enable relay ( IF you have the right key in)
13=Delayed acc.buss relay
14= BBBBBBEEEEEEEEPPPPP (horn)



Clearing CCM Codes

Jump pin's A & G
Key ON
Press the Trip/ODO button till the 1.7 appears in the module window.

HOLD the ENG/MET button till ( --- ) shows up in the speedo window.

You have now cleared the CCM errors,
( now if there is still a problem.. this will come back and report an error the next time you poll.)

Key off

Remove Jumper

Mike
 
anyways

Hey, man,, did u get any codes on your car,,, is there a code,, 24 i think it is,, its speed control


anyways, i used to get a speed control code, all the time

but i had other engine problems
i finally replaced my ECM and the code cleared, maybe yours is more worse then mine

thats all i know,,
 

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