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Ron
Ron, ASE Certified Technician
Category: Ford
Satisfied Customers: 23821
Experience:  23 years with Ford specializing in drivability and electrical and AC. Ford certs and ASE Certs
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ZX2 speedometer not working

Expert:  eddie replied 7 years ago.
ill do the best i can to help,first have you checked for codes,fuses(10amp fuse in engine compartment OBD11)the 10 amp fuse in passenger compartment,does the cruise control work,have you checked continuity from instrument cluster at pin 11 connector a blue wire to ground.ground connector is somewhere near starter moter. should be 0 olhms straight path to ground.blue and white wire from vss sensor connect to battery junction box(left side of engine compartment above wheel well).also measure resistance between ground and instument cluster harness connector c pin1(green wire)resistance should be more than 10kohms.If resistanced is more than 10kohms than replace the fuse.Im new to this web site so please good feedback and accept.Ill do what i can to help you.
Customer: replied 7 years ago.
Thanks for the reply.

P0500 - Vehicle speed sensor malfunction.
Reset it twice and it comes back.

No cruise control.

Traced VSS wires to battery junction box - 12v at box and wires in good shape.

I'll check the resistance here shortly.

Is connector C the black harness?
Customer: replied 7 years ago.
double post.
Expert:  eddie replied 7 years ago.
im still studing the diagram,flow chart indicates to check continuityat vss pigtail.If resistance is not170-270 replace the speed sensor,if resistance is 170-270ohms replace the pcm.DTC500 indicates faulty vss,open or shorted circuit,or faulty pcm
Customer: replied 7 years ago.
I'll run to the junkyard and get a pcm tomorrow since i need a clockspring and dome light also.

Just curious, what voltage do the instruments use? I had an 8.5 v reading on the VSS wires at the instrument cluster.
Expert:  eddie replied 7 years ago.
most american vehicle use a 5 volt reference.also if you install a new pcm you might have to reprogam the ignition key and possibly the vin number to the new pcm.8.5 volts doesnt sound right,even with a 12 volt battery.also have you checked the fuses with a test light? will be home about 7 oclock disafternoon.will work with more on this problem.
Customer: replied 7 years ago.
Do you have a pinout diagram you can send me for the instrument cluster and three harnesses? [email protected]
From what i've read, some wire colors are different due to outsourcing.

Facing the dashboard, there are 3 wiring harnesses going to the instrument cluster. On the left (white), on the bottom right (white) and top right (black). Is the top right harness connector C?

Please clarify when the fuse should be replaced:
also measure resistance between ground and instument cluster harness connector c pin1(green wire)resistance should be more than 10kohms.If resistanced is more than 10kohms than replace the fuse.

From your first post:
All fuses checked ok.
The blue wire is +, so i can't check continuity, just 12v.

Resistance is around 235 ohms. Put in a new PCM, no change:
i'm still studing the diagram,flow chart indicates to check continuityat vss pigtail.If resistance is not170-270 replace the speed sensor,if resistance is 170-270ohms replace the pcm.DTC500 indicates faulty vss,open or shorted circuit,or faulty pcm


Customer: replied 7 years ago.
I just remembered that the horn stopped working around the same time as the speedometer. I think i lost ground to the horn, so i attached the negative horn wire to the negative cruise control wire, now the horn works.
Customer: replied 7 years ago.
Relist: Other
Continuing conversation.
Customer: replied 7 years ago.
Relist: I still need help.