No Speedo - ABS light

AllOut0606 · 06-05-2007, 02:25 AM

So i took my truck to local retards aka my sh**ty ford dealer (not saying all ford dealers are bad) and after paying the $90 they came to the conclusion that the cause for no speedo, odometer, ABS light, and flashing OverDrive light was caused by a faulty GEM. So i bought the GEM and put it in tonight. After 4 hours of painstaking work, i replaced the GEM. It would have been faster, but i was using an allen key instead of a star key to get the screws holding it out. Cleaned up and took it for a spin. The new GEM did absolutly f***ing nothing. I'm pissed.

Is there something other then a GEM or rear speed sensor that could be causing this annoying and expensive problem?

Symptoms - No Speedometer, No odometer, Flashing OD light, and ABS light - which means my ABS isnt working. Cuz i went sideways trying to stop in the rain last night.

PLEASE HELP!!

**trick76cj5** · 06-05-2007, 02:38 AM

That sucks!

What's GEM stand for? I've always hear that part called the VSS. Did they hook a code reader up to see what kind of info they were getting from it? Sounds like you could have a broken/chaffed/grounded wire somewhere.

**plainredtruck** · 06-05-2007, 02:54 AM

It's just a late-night, wine-addled guess, but here goes . . .

It's probably the VSS which resides in your differential housing. Much cheaper (and easier to get to :sofa ) than the GEM, or another sensor (ABS sensor?).

Hie thyself to the local PSD guru who has AE or an NGS scanner and see if that person can help you.

I've replaced both the GEM and the VSS on my truck. When the GEM failed, I couldn't even start my truck. I don't remember precisely the VSS symptoms, but I do remember the Speedometer not working.

Wish you well.

prt

AllOut0606 · 06-05-2007, 03:14 AM

Quote:

Originally Posted by plainredtruck

It's just a late-night, wine-addled guess, but here goes . . .

It's probably the VSS which resides in your differential housing. Much cheaper (and easier to get to :sofa ) than the GEM, or another sensor (ABS sensor?).

Hie thyself to the local PSD guru who has AE or an NGS scanner and see if that person can help you.

I've replaced both the GEM and the VSS on my truck. When the GEM failed, I couldn't even start my truck. I don't remember precisely the VSS symptoms, but I do remember the Speedometer not working.

Wish you well.

prt

how does one get to the VSS and what does that stand for?

GEM = General Electronics Module

**trick76cj5** · 06-05-2007, 04:23 AM

The VSS (vehicle speed sensor) is located on top of the rear differential. I believe there is 1 10mm bolt that holds it in place. When the VSS goes out you loose your speedo, abs, the SES light comes on. . .all symptoms you are describing. They are very easy to replace. . .and are basically cps's so are very commonly failing parts on our trucks. . .but i don't think they're too pricey, i can't remember, brian replaced mine w/my tranny. . .guess you could say i paid 4300 for mine, and he threw a tranny in for free

. Sorry, it's late, i'm going to bed now. Let us know if that works for you.

AllOut0606 · 06-05-2007, 12:42 PM

i have replaced two of VSS, i didnt know what you were talking about because i call it a rear speed sensor. i tried replacing those before i bought the GEM. It didnt fix the problem. Thanks for the input everyone.

Any other things causing this?

UnlimitedDiesel · 06-05-2007, 01:17 PM

Check your wiring going to the VSS. There should be two wires, and sometimes they get corroded at the frame. I will try to explain to the best I can. "USUALLY" we see this corrosion right where the wiring comes off of the frame and starts its journey down to the VSS. it is around the shock area I believe. Also check the plug at the VSS, Sometimes there is corrosion there also.

S&Dqtrhrs · 06-05-2007, 01:17 PM

No sense in guessing...It requires meters and probes to check everything it could be...Without being there to assist, I'd highly recommend you visit your local library and hit the better manuals they carry...Usually they will print the info you need at a nominal price and save you the migrain....It could be anything from corrosion to 1 of numerous grounds...Read the proper section and you will get some excellant tips...

UnlimitedDiesel · 06-05-2007, 01:21 PM

No one is guessing here. We are all making suggestions that we have seen in the past with our own trucks or others, that have had the same issue. I am not against going to the library, but common sense tells me that If he checks for the problems that we have all stated at least he will have a good starting point if we are all wrong.

S&Dqtrhrs · 06-05-2007, 01:37 PM

I'm not trying to offend anyone...Not knowing all the circumstances of available tooling and experience,and knowing if he looks at a wiring schematic, he will see all the places that issues could and will arise.. You are absolutely right, they are all good starting places...

06-05-2007, 02:25 AM	#1
AllOut0606 TDG Mafia Member # 70 Join Date: Jan 2007 Location: Maryland Posts: 426 Points: 1,708 Thanks: 1 Thanked 0 Times in 0 Posts	No Speedo - ABS light So i took my truck to local retards aka my shty ford dealer (not saying all ford dealers are bad) and after paying the $90 they came to the conclusion that the cause for no speedo, odometer, ABS light, and flashing OverDrive light was caused by a faulty GEM. So i bought the GEM and put it in tonight. After 4 hours of painstaking work, i replaced the GEM. It would have been faster, but i was using an allen key instead of a star key to get the screws holding it out. Cleaned up and took it for a spin. The new GEM did absolutly fing nothing. I'm pissed. Is there something other then a GEM or rear speed sensor that could be causing this annoying and expensive problem? Symptoms - No Speedometer, No odometer, Flashing OD light, and ABS light - which means my ABS isnt working. Cuz i went sideways trying to stop in the rain last night. PLEASE HELP!! __________________ 2000 F250 7.3L CC Lariat 4X4 SB;* Performance:TS Performance Tuner///K&N Intake///Custom 5" Straight Pipe///6.0 Intercooler///B&M Trans Cooler///Foil Delete///Zoodad///CCV. Interior: Autometer Gauges: Pyro, Trans, and Boost///Alpine In-Dash DVD Player///Audiobahn Sound System///Cobra 29 CB. Exterior: Pro Comp 4" Lift///36" Super Swampers///16" wheels///Dual Hadley Peterbilt Horns///Viair 380c Compressor///Two 3 gallon air tanks///20% Tint///Warn Standard Hubs. -Marshall-

06-05-2007, 02:38 AM	#2
trick76cj5 Supporting Vendor Join Date: Jan 2009 Posts: 297 Points: 3,231 Thanks: 2 Thanked 21 Times in 10 Posts	That sucks! What's GEM stand for? I've always hear that part called the VSS. Did they hook a code reader up to see what kind of info they were getting from it? Sounds like you could have a broken/chaffed/grounded wire somewhere. __________________ -Brad Desatnik

06-05-2007, 02:54 AM	#3
plainredtruck Senior Member Join Date: Dec 2008 Location: Hickory Tavern, SC Posts: 4,090 Points: 26,679 Thanks: 275 Thanked 444 Times in 285 Posts Images: 11	It's just a late-night, wine-addled guess, but here goes . . . It's probably the VSS which resides in your differential housing. Much cheaper (and easier to get to :sofa ) than the GEM, or another sensor (ABS sensor?). Hie thyself to the local PSD guru who has AE or an NGS scanner and see if that person can help you. I've replaced both the GEM and the VSS on my truck. When the GEM failed, I couldn't even start my truck. I don't remember precisely the VSS symptoms, but I do remember the Speedometer not working. Wish you well. prt __________________ '99 F250 X-cab 2wd powered by DP-Tuner My Photography addiction Mafia # 27

06-05-2007, 04:23 AM	#5
trick76cj5 Supporting Vendor Join Date: Jan 2009 Posts: 297 Points: 3,231 Thanks: 2 Thanked 21 Times in 10 Posts	The VSS (vehicle speed sensor) is located on top of the rear differential. I believe there is 1 10mm bolt that holds it in place. When the VSS goes out you loose your speedo, abs, the SES light comes on. . .all symptoms you are describing. They are very easy to replace. . .and are basically cps's so are very commonly failing parts on our trucks. . .but i don't think they're too pricey, i can't remember, brian replaced mine w/my tranny. . .guess you could say i paid 4300 for mine, and he threw a tranny in for free . Sorry, it's late, i'm going to bed now. Let us know if that works for you. __________________ -Brad Desatnik

06-05-2007, 12:42 PM	#6
AllOut0606 TDG Mafia Member # 70 Threadstarter Join Date: Jan 2007 Location: Maryland Posts: 426 Points: 1,708 Thanks: 1 Thanked 0 Times in 0 Posts	i have replaced two of VSS, i didnt know what you were talking about because i call it a rear speed sensor. i tried replacing those before i bought the GEM. It didnt fix the problem. Thanks for the input everyone. Any other things causing this? __________________ 2000 F250 7.3L CC Lariat 4X4 SB; Performance:TS Performance Tuner///K&N Intake///Custom 5" Straight Pipe///6.0 Intercooler///B&M Trans Cooler///Foil Delete///Zoodad///CCV. Interior: Autometer Gauges: Pyro, Trans, and Boost///Alpine In-Dash DVD Player///Audiobahn Sound System///Cobra 29 CB. Exterior: Pro Comp 4" Lift///36" Super Swampers///16" wheels///Dual Hadley Peterbilt Horns///Viair 380c Compressor///Two 3 gallon air tanks///20% Tint///Warn Standard Hubs. -Marshall-

06-05-2007, 01:17 PM	#7
UnlimitedDiesel <<< Fire Hoses Join Date: May 2007 Posts: 80 Points: 2,929 Thanks: 0 Thanked 8 Times in 4 Posts	Check your wiring going to the VSS. There should be two wires, and sometimes they get corroded at the frame. I will try to explain to the best I can. "USUALLY" we see this corrosion right where the wiring comes off of the frame and starts its journey down to the VSS. it is around the shock area I believe. Also check the plug at the VSS, Sometimes there is corrosion there also. __________________ 95 Ford F-250 2wd, New Engine, Full Billet Auto, Twin Turbos, Spearco 6.0 IC, 455cc FAST "Fire Hose Rocket" Injectors, Gen3 Big Oil 498hp/900ft lb's - 5/29/2008 TRUCK PICS http://good-times.webshots.com/album/569105257cBxDXW RDRCM #23

06-05-2007, 01:17 PM	#8
S&Dqtrhrs Member Join Date: Jun 2007 Posts: 94 Points: 35 Thanks: 0 Thanked 0 Times in 0 Posts	No sense in guessing...It requires meters and probes to check everything it could be...Without being there to assist, I'd highly recommend you visit your local library and hit the better manuals they carry...Usually they will print the info you need at a nominal price and save you the migrain....It could be anything from corrosion to 1 of numerous grounds...Read the proper section and you will get some excellant tips... __________________ 1989 Ford F-250 4x4 5 speed 7.3 IDI 1991 Ford F-350 crew cab dually 2wd 5.9 cummins dodge od auto 5 quarterhorses

06-05-2007, 01:21 PM	#9
UnlimitedDiesel <<< Fire Hoses Join Date: May 2007 Posts: 80 Points: 2,929 Thanks: 0 Thanked 8 Times in 4 Posts	No one is guessing here. We are all making suggestions that we have seen in the past with our own trucks or others, that have had the same issue. I am not against going to the library, but common sense tells me that If he checks for the problems that we have all stated at least he will have a good starting point if we are all wrong. __________________ 95 Ford F-250 2wd, New Engine, Full Billet Auto, Twin Turbos, Spearco 6.0 IC, 455cc FAST "Fire Hose Rocket" Injectors, Gen3 Big Oil 498hp/900ft lb's - 5/29/2008 TRUCK PICS http://good-times.webshots.com/album/569105257cBxDXW RDRCM #23

06-05-2007, 01:37 PM	#10
S&Dqtrhrs Member Join Date: Jun 2007 Posts: 94 Points: 35 Thanks: 0 Thanked 0 Times in 0 Posts	I'm not trying to offend anyone...Not knowing all the circumstances of available tooling and experience,and knowing if he looks at a wiring schematic, he will see all the places that issues could and will arise.. You are absolutely right, they are all good starting places... __________________ 1989 Ford F-250 4x4 5 speed 7.3 IDI 1991 Ford F-350 crew cab dually 2wd 5.9 cummins dodge od auto 5 quarterhorses

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