2012 E-350 speedo reading fast
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Tuned
Joined: Apr 2006
Posts: 410
Likes: 1
From: West Virginia
2012 E-350 speedo reading fast
Hi guys, I could use a little help. I have a 2012 E-350 box truck, former moving truck, Budget I think. The problem I'm having is the speedometer is reading fast by about 4 MPH on average (GPS). A few days ago is was way off, say 30 mph. It has two sensors on the trans, input and output, none on the axle. Which one would cause the problem? Should I just replace them both? Or is it something else I'm missing? Thanks in advance.
(edited...the speedo is reading fast, not slow. If it shows 25 I'm doing 21, again by GPS)
(edited...the speedo is reading fast, not slow. If it shows 25 I'm doing 21, again by GPS)
Senior User
Joined: Jan 2010
Posts: 199
Likes: 9
4 mph off is not unheard of. I would first compare the tire size that's on the vehicle with what the door jamb sticker specifies.
Now 30 mph off is definitely not right. The gauges themselves are a common issue on these vehicles so I would get a scan tool that shows live data (forscan, torque pro, etc) and check to see what the sensor is outputting. At least then you will know if you should be looking at the sensors or the cluster itself.
Now 30 mph off is definitely not right. The gauges themselves are a common issue on these vehicles so I would get a scan tool that shows live data (forscan, torque pro, etc) and check to see what the sensor is outputting. At least then you will know if you should be looking at the sensors or the cluster itself.
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Tuned
Joined: Apr 2006
Posts: 410
Likes: 1
From: West Virginia
Tire size is correct, and all tires are the same size. The other day I was doing around 55 by speedo, then is just slowly got slower and slower. Settled in around 25. I stopped shut off the truck, picked up materials for a job. Maybe 15 min. When I started up and took off for the job site the speedo was back to about 4 mph off. Really makes me mad because the speed governor is turned on at 75 mph, on the highway I can only do a max speed of 71.
Fleet Owner
Joined: Aug 2010
Posts: 21,255
Likes: 1,657
From: Reynoldsburg, Ohio
Your speedo issues could be within the instrument cluster itself---that year had the CAN-bus network system fully integrated. Its possible the ECM is at fault as well. Check with several well-respected and knowledgeable local independent shops for someone who can dig into the CAN-bus network to determine if your sensors are at fault. Until that time I'd not change the sensors hoping that's the cure or fix.
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Tuned
Joined: Apr 2006
Posts: 410
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From: West Virginia
Well I hate to hear that. I live in a small town, 14,000 people in the entire county and one Ford dealer in the four counties around me. I don't trust any of them (local shops) to know what they are doing. Heck the Ford dealer has only been there for a hand full of years, so they have no older truly experienced techs working.
Cargo Master
Joined: Sep 2012
Posts: 2,112
Likes: 286
From: Eastern TN
Can you confirm with an OBD scanner that has vehicle speed display?
Bucking the advice trend and with no technical knowledge, let’s assume the speed governor signal doesn’t come from through the gauge cluster in a CAN system (it does in some older cars), in which case the problem is upstream of the speedo and speed governor. I don’t read of a lot of speedo problems with these vans so maybe try a good used sensor. Question is whether sensors are calibrated to diff ratio and tire size or any E-series sensor will work with your truck.
If your truck has ABS or traction control, the speed signal might not come from the transmission or just one sensor.
Sixto
07 E350 5.4 176K miles
Bucking the advice trend and with no technical knowledge, let’s assume the speed governor signal doesn’t come from through the gauge cluster in a CAN system (it does in some older cars), in which case the problem is upstream of the speedo and speed governor. I don’t read of a lot of speedo problems with these vans so maybe try a good used sensor. Question is whether sensors are calibrated to diff ratio and tire size or any E-series sensor will work with your truck.
If your truck has ABS or traction control, the speed signal might not come from the transmission or just one sensor.
Sixto
07 E350 5.4 176K miles
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