When you click on links to various merchants on this site and make a purchase, this can result in this site earning a commission. Affiliate programs and affiliations include, but are not limited to, the eBay Partner Network.
Hi, I have 1992 F150 XLT 2WD 5.0 V8 E4OD extended cab. The speedometer displays a wrong speed. Lets say I'm going 60 km/h but the speedometer displays around 100 km/h (60 mph). So when I'm driving, I have too look at mph scale and that number would be roughly my actual speed in km/h. Also my dash seems to have been replaced by the previous owner, because it is showing lower mileage (km) than what is recorded in Carfax.
Has anyone seen this? What would you recommend to check?
Someone replaced the cluster or at least the speedometer. The speedometer is calibrated for the tire size of that vehicle. You will need to recalibrate it for your tire size. There are a limited number of times that can be done so hopefully there is at least one left.
Either that or someone replaced the rear end with one that has lower gears? (just replaced the gearset)?
Or they reprogrammed the PSOM when it had big tires on it?
It will need to be reprogrammed for your current tire size and rear axle ratio
It has been a real long time since I have programmed one
I believe it starts with axle ratio, and then moves on to tire size when using a NGS
Either that or someone replaced the rear end with one that has lower gears? (just replaced the gearset)?
Or they reprogrammed the PSOM when it had big tires on it?
Going with the axle gear change theory, how do you explain the lower mileage than what what was last recorded on the Carfax?
I agree with those saying cluster has been replaced with a used cluster. Odometer mileage is saved in the cluster as well as the tire ratio so if it was changed they have the mileage that came with the replacement cluster and different tire size than they had on the truck. Also if you didn't know the speed signal goes through the PSOM where it is converted to a DC voltage and sent to the ECM. The ECM uses the signal to control the transmission, so besides having correct speed on the speedometer you want to calibrate the PSOM to the correct tire size for correct shift points.
Thank you all for your replies! @My4Fordtrucks I tried calibrating the speedometer for the tire size, but it did not work, I suspect there are no calibrations left. @ThisOldBob The transmission does shift very early in my opinion, which does make sense, as the speedometer is displaying higher speed than the reality.
So I picked up a used PSOM from a junkyard and will try installing it, see attached images. From what I understand, I just need to replace the board that is behind the speedometer, correct?
Rezvani's Latest Post-Apocalyptic Monster Is a Ford F-150 Raptor Underneath
Slideshow: Called the Fortress, the 850-horsepower pickup combines Raptor underpinnings with military-inspired features, survival equipment, and a starting price of $285,000.
