Diagnostic Code 24, Speed Senor - ZR-1 Net Registry Forums

HIZNHRZ · 05-28-2012

Driving home from a day trip last weekend the speedometer of my 91 ZR-1 stopped working. Along with the speedometer, the trip meter, mpg, gas tank range funtions, and my odometer stopped working as well.

Among other problems I'm getting an error code 24 from the ECM and error codes H41 and H24 from the CCM. It appears I've got a bad Speed Senor. It looks like the the code 41 is the CCM being pissed off that the data link between the ECM and CCM has been broken.

I can find diagrams of the Speed Sensor mounted in the tranmission Extension Housing but I can't find a sensor part number. Anyone know if this is a ZR-1 unique part or common to all ZF 6-speed transmissions. Also, anyone replaced the Speed Sensor before? If so, should I also buy a replacement O-ring? Anything else?

Thanks.

VetteMed · 05-28-2012

Should be the same PN for all ZF 6-speed cars, ZR-1 or base.

I haven't replaced one, but It seems like a fairly simple process.

GM PN for 91-95 is 10456089
GM PN for 90 is 25007224 - 25007308 (both listed on Kurt's website - whiteracingproducts.com

VetteMed · 05-28-2012

ROckauto also has a few different brands, including the Delco 10456089.

tpr60 · 05-28-2012

Changed one on a friends Z years ago, little tight to access even on a lift. Seam to remember something about the electrical connector being different on a 1990 then on later years??? Change the o-ring.

HIZNHRZ · 05-28-2012

Andrew, thanks for the part number. Found a few of them already...

05-28-2012	#1
HIZNHRZ Join Date: Apr 2004 Location: Germantown, MD Posts: 738	Diagnostic Code 24, Speed Senor Driving home from a day trip last weekend the speedometer of my 91 ZR-1 stopped working. Along with the speedometer, the trip meter, mpg, gas tank range funtions, and my odometer stopped working as well. Among other problems I'm getting an error code 24 from the ECM and error codes H41 and H24 from the CCM. It appears I've got a bad Speed Senor. It looks like the the code 41 is the CCM being pissed off that the data link between the ECM and CCM has been broken. I can find diagrams of the Speed Sensor mounted in the tranmission Extension Housing but I can't find a sensor part number. Anyone know if this is a ZR-1 unique part or common to all ZF 6-speed transmissions. Also, anyone replaced the Speed Sensor before? If so, should I also buy a replacement O-ring? Anything else? Thanks.

05-28-2012	#2
VetteMed Join Date: Mar 2009 Location: Orlando, FL Posts: 1,828	Re: Diagnostic Code 24, Speed Senor Should be the same PN for all ZF 6-speed cars, ZR-1 or base. I haven't replaced one, but It seems like a fairly simple process. GM PN for 91-95 is 10456089 GM PN for 90 is 25007224 - 25007308 (both listed on Kurt's website - whiteracingproducts.com __________________ 2004 Z06/Z16 LeMans Commemorative Edition 1991 ZR-1 #302 White/Gray (sold) 1991 ZR-1 #1147 Red/Saddle (sold)

05-28-2012	#3
VetteMed Join Date: Mar 2009 Location: Orlando, FL Posts: 1,828	Re: Diagnostic Code 24, Speed Senor ROckauto also has a few different brands, including the Delco 10456089. __________________ 2004 Z06/Z16 LeMans Commemorative Edition 1991 ZR-1 #302 White/Gray (sold) 1991 ZR-1 #1147 Red/Saddle (sold)

05-28-2012	#4
tpr60 Join Date: Feb 2011 Location: Salinas, Ca Posts: 159	Re: Diagnostic Code 24, Speed Senor Changed one on a friends Z years ago, little tight to access even on a lift. Seam to remember something about the electrical connector being different on a 1990 then on later years??? Change the o-ring.

05-28-2012	#5
HIZNHRZ Join Date: Apr 2004 Location: Germantown, MD Posts: 738	Re: Diagnostic Code 24, Speed Senor Andrew, thanks for the part number. Found a few of them already...