04 F150 speedometer question

Therich81 · Post by **Therich81** » Wed Oct 13, 2010 4:07 am

Hey I noticed that the speedo on my trinity and the one in my truck do not read the same, the one in my truck is about 4-5% faster. Which one would be the accurate one?

Post by **mikel** » Wed Oct 13, 2010 11:45 am

That is odd...what is the name of the PID?

Therich81 · Post by **Therich81** » Sun Oct 17, 2010 10:04 pm

Sorry it has taken me so long to reply, work etc. The PID is under performance and is named "Engine RPM(RPM)". There is also a PID named "Engine speed(RPM), and both seem to read the exact same values.(4-5% lower than the truck's dash speedo.)

Post by **mikel** » Mon Oct 18, 2010 10:11 am

any chance your speedo is off due to tires or gear swap?

Therich81 · Post by **Therich81** » Mon Oct 18, 2010 7:18 pm

I do run different size tires, but was under the impression that i could recal my speedo using the trinity. My summer setup is 285/50r20 and i set the revs/mile to 636 i think it was, and now with my winter setup 315/70r18 i have the revs/mile set to 570 iirc. Does those numbers only change the speed readouts on the trinity itself? or is it a recal on the truck speedo as well?

Post by **mikel** » Tue Oct 19, 2010 9:46 am

correcting the size in the tune should correct the speedo, yes, but the question I am asking is, which is really odd?

Can you verfy via GPS if the Trinity speed or speedo speed is correct?

Therich81 · Post by **Therich81** » Tue Oct 19, 2010 5:16 pm

I do not own a GPS or know anyone who does. I might be able to find an iPhone app. if i find anything out i will let you know.

Therich81 · Post by **Therich81** » Thu Oct 21, 2010 10:07 pm

Well according to my iPhone GPS app, they were both out by a good margin. the trinity was the closer of the two. My app read 92km/h, the trinity read 100km/hr and my truck speedo read 105km/h.

I ended up tuning the revs/mile to match the gps speed with my speedo on the truck just to keep mileage accurate. Will just fill that guage spot with a different PID.

Still unsure as to why/how the readings are different by 5%, but not really an issue.

Post by **mikel** » Fri Oct 22, 2010 8:57 am

Odd, Im checking into it.

Therich81 · Post by **Therich81** » Wed Oct 27, 2010 8:15 pm

Hey Mike, I think I figured out what is happening. I started my truck up in test mode (hold the odo/trip button when starting the engine) and cycled through the displayed units to speed, and the digital displayed speed matches what the trinity is reporting. So it would seem that the needle on my trucks speedo is the incorrect one, and the trinity is fine.

Post by **mikel** » Thu Oct 28, 2010 10:31 am

Nice, good find.

04 F150 speedometer question

04 F150 speedometer question

RE: 04 F150 speedometer question