Check Engine Light - Forums - Official C4 Vette Registry

SPONSOR AD

Support our Vendors! | Advertise Here

Topic: Check Engine Light

in Forum: C4 General Discussion

Already a Member?
Login
Not yet a Member?
Register for Free!

Check Engine Light (1/3)
9/29/15 12:43pm

cruiserdon
Standard Member
Send Private Message

Lenexa, KS - USA

Vette(s):
1991 Coupe, dark red with saddle interior, automatic. Original car, no customization.

Joined: 9/25/2015
Posts: 1

My '91(standard coupe/automatic) has been thoroughly code checked and mechanically performs well within specs. The car is always driven in the overdrive position for the auto transmission and shifts properly. However, the "shift now" indicator lights comes on, on the dash right between 55-60 mph while accelerating, closely followed be the CES light on the control panel coming on and staying on until the end of the drive regardless of speeds up and down during the run. As I said, everything with the ignition, fuel system, EGR, etc., etc., has been checked out. Our theory now is that this is likely something within electronics getting some form of false message to trigger the shift indicator well after the transmission has already shifted up.

Let me hear from you if have shed any light on getting this distraction eliminated from an otherwise highly enjoyable ride.

Quote

Our Sponsors help support C4VR

Re: Check Engine Light (2/3)
10/1/15 10:40pm

Adams' Apple
Standard Member
Moderator
Send Private Message

Duncanville, TX - USA

Vette(s):
1985 Coupe-L98/Auto,Bright Red/Carmine. 1974 Coupe-L48/4speed, Medium Red Metallic/Black Deluxe.

Joined: 3/18/2009
Posts: 2230

I don't understand why your automatic car would have the "shift now" light in the first place. I'd have to check into that. Have you tried pulling any codes out of it while the CES light is on? That would give you/us an idea of what the PCM thinks is going on, and would give you a starting place to diagnose the issue.

______________

Joel Adams
My Link

(click for Texas-sized view!) NCRS

"Money can't buy happiness -- but somehow it's more comforting to cry in a CORVETTE than in a Kia"

Quote

Re: Check Engine Light (3/3)
10/7/15 8:20pm

Phat98
Standard Member
Send Private Message

Crystal Springs, MS - USA

Vette(s):
1973 Mille Miglia Red LS5 1981 Claret Red 1982 White 1985 Silver Metallic 1988 Yellow 1993 Torch Red ZR-1 1994 Torch Red Coupe LT1 1996 Dark Purple Metallic LT4 2000 Torch Red 2001 Light Pewter 2003 Z06 Millennium Yellow 2009 Atomic Orange

Joined: 7/29/2011
Posts: 33

Check your vacuum lines...

______________

1973 Mille Miglia Red LS5 - SOLD

1981 Dark Claret Metallic - SOLD

1982 White

94 Torch Red LT1

96 Dark Purple Metallic LT4

02 Black Convertible - SOLD

03 Millennium Yellow Z06
09 Atomic Orange Z51

Quote

Our Sponsors help support C4VR