Faulty Speedometer 2022 Gladiator Willys

[ApexJeep]

Curious if anyone knows much about speedometers. When I get above 40 MPH, my analog speedometer is about 2mph faster than the digital readout. I‘ve tested it with a GPS based app on my iphone. My app is matching the digital readout. I have heard that if the analog speedometer is off, it can affect your accrued mileage, which is not a good thing!

Anyone know how this is fixed? I’ve read a new Instrument / speedometer cluster might be needed. I’m just not sure how that part in particular would impact accrued mileage. Anyone with any experience with this? Calling the dealership tomorrow.

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[ShadowsPapa]

Curious if anyone knows much about speedometers. When I get above 40 MPH, my analog speedometer is about 2mph faster than the digital readout. I‘ve tested it with a GPS based app on my iphone. My app is matching the digital readout. I have heard that if the analog speedometer is off, it can affect your accrued mileage, which is not a good thing!

Anyone know how this is fixed? I’ve read a new Instrument / speedometer cluster might be needed. I’m just not sure how that part in particular would impact accrued mileage. Anyone with any experience with this? Calling the dealership tomorrow.

Yup - my 2020 Overland has been like that from November 12th, 2019.
It may have been that way before that date but Jeep was still transporting it to the dealer before that date.
I got rid of the digital display on the 2nd day of ownership.
Without the digital numbers, which IMO look clunky and amateurish with no style, it doesn't bother me. Those numbers are ugly.

 

[NC_Overland]

I think you should have it lemon lawed.

they’re all like that. I joked because you’re over thinking it too much.

 

[CerOf]

So, does one pull speed data from the gps and the other from a wheel speed sensor?

 

[chadinsc]

you could adjust it with one of the tools for tire sizes. just play with the numbers until you get the right one to make it accurate. i have heard dealers can set it for different tire sizes alao

 

[ApexJeep]

So, does one pull speed data from the gps and the other from a wheel speed sensor?

i’m curious as well. I get it seems like a minor problem, but it is 2.8%….so when I’ve driven 10,000 miles, it’s going to read 10,280….I’d prefer that not to be the case. Ive owned Tazers before and they can set your tire size and gear ratio to correct the speedometer, but I’m bone stock. i don’t believe they offer an adjustment for the speedometer alone.

 

[ShadowsPapa]

you could adjust it with one of the tools for tire sizes. just play with the numbers until you get the right one to make it accurate. i have heard dealers can set it for different tire sizes alao

Mine is adjusted and accurate - by ODOMETER - which is the ideal way.
When my odometer says I have moved 17.5 miles, the GPS says I have gone 17.5 - and yet I have that 2 mph difference on mine and it's always been that way.
It was that way before I set for tire size and it's that way after - there was no difference at all.
I'm wondering if it's how the analog speedometer was assembled......... the pointer may be off or the scale is off.

This is not a tire size issue. (yes, there are multiple ways, multiple tools, to calibrate the speedometer or set tire size.)
Yes, dealers could but many won't.

but it is 2.8%….so when I’ve driven 10,000 miles, it’s going to read 10,280….I’d prefer that not to be the case.

How do you know which the PCM is pulling the miles driven from? Hmmm? Is it using the digital or the analog?
Mine is exactly spot-on as far as odometer.
I set my trip meter to 0 miles.
I fired up my Garmin and set the trip tracker to 0 miles.
I drove over 17 miles and compared.
Both read the exact same amount to the tenth of a mile.
GPS matches my truck's odometer.

So - how do you know your odometer isn't accurate? How do you know it's not saying 10,000 when you have driven 10,000?
Are you sure the odometer isn't tied to the digital speedometer? (the lower reading)?

 

[sharpsicle]

Don't overthink this. An analog readout being off by 1 or 2mph at high speed is trivial at best. This happens across all manufacturers. Some even do it to the tune of 5mph over actual speed on purpose. There's a thread out there where we discussed this in detail, but in the end there's no problem here and no fix to be had.

In regards to it getting "more inaccurate" as you speed up, that's not really true either. You're dealing in percentages when it comes to accuracy but then observing discrete numbers to say "it's worse". In reality it isn't. 1% or 2% off at a lower speed like 25mph is at or below +½mph. You probably won't notice that on an analog cluster. At 50mph it's +1mph. You might notice that easier. But that doesn't mean the problem started at 50mph. The same level of accuracy exists at all speeds, you just notice it more as you go faster. Again, this is something that exists on all manufacturers that use analog speedometers. There's no problem here.

As @ShadowsPapa mentioned, odometer is the real accuracy that you really want dialed in. If the odometer reads correctly, but the speedometer needle is just a tiny bit higher than where you think it should be, don't worry about it. Don't test the GPS against your analog speedometer, test the GPS against your total miles travelled.

 

[ApexJeep]

Good points, probably best to zero out the trip odometer and measure a straight road to get the distance traveled to see if it accurate. I’d rather not have to take it to a dealer to be honest!

 

[Bananaman]

You know, it could be the way the gauges are positioned. I noticed it too, but then I thought, I'm looking at these at an angle. If you move your head to look at the gauge straight on the reading is slightly different. Same with the tach. It's a Jeep thing? LOL

 

[ShadowsPapa]

Good points, probably best to zero out the trip odometer and measure a straight road to get the distance traveled to see if it accurate. I’d rather not have to take it to a dealer to be honest!

Your dealer won't do a thing about the difference between the SPEEDOMETER readings.
If they did, they'd have to deal with thousands of them.

Here's how mine is currently configured (from my 2020 BCM)


VehConfig 4:
___________________
Transfer Case High Ratio (0-16.382): 1.000
Axle Ratio (0-65.534): 3.730
Transfer Case Low Range Reduction Ratio (0-65.534): 2.720
Dynamic Tire Circumference (All or Rear) (0-65534 mm): 2508.000 mm

Note the dynamic tire circumference.
My tires are 32.07 (advertised typically as 32.1" diameter tires)
The actual measured circumference of a circle that is 32.07 - 32.1 is 2559 mm to 2561 mm
So if you measure the tire or go by the advertised numbers, it's going to be imperfect.
I set mine by GPS miles driven, not speedometer.

These are the numbers I am most concerned with - what's the PCM say about it...........


CARB Freeze Frame:
___________________
Fault code: P0303
PCM Mileage since MIL On: 0.00 miles
PCM Odometer: 950.27 miles
Open Loop - Bank 1: No
Closed Loop - Bank 1: Yes

(the above captured from a pretty darned new Jeep)

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