Speedometer off and blinking TPMS

macleanflood

JK Enthusiast
Joined
Jul 4, 2022
Messages
112
Location
Fall Creek, OR
Just bought this 2012 JK. 3.8. 6 speed. 30/44. Stock 3.21 gears. Replaced the bald 35s with Mickey's...love them other than they're 33 and 3/4"... should have bought 37s if I wanted 35s. Aftermarket 18" rims.

Whole ton of codes:

C107C - brake switch 1 bad - end of the switch looks mushroomed so I might start here.

C1000 - brake pedal switch 1 performance

C2103 - system voltage high

C2101 - high battery voltage

C121C - Torque requested not possible

C1078 - tire revolution range performance

U1084 - radio, freedom top is leaking...got a new seal, eventually replacing radio...have a cheap $20 Walmart Dual AV unit and a Schotche tell the can bus the radio exists harness...which might not be doing what it should.

P0513, BA124 - incorrect immobilizer key, key code not programmed...Jeep came with an ACE hardware transponder key... another place to start might be a dealer key. JScan can't read the pin. Dealer wouldn't give me the pin either...had to try.

C1501, 2, 3 and 4 - tire pressure internal component failure. Tire shop checked all the senders and they're good. Odds of all four readers failing are low...seems to point to a wiring issue.

Speedo is off despite setting it correctly and incorrectly in JScan. Using an endorsed reader.

TPMS light started coming on after the new tires...and after I switched it back on after some trails running 15psi.

Original tires were from 2011. Discount Tire had fun debeading them.

Thoughts?

-Mac
 
After resetting the speedometer you need to double check it with a GPS.

You should not have that tall of a tire with those stock gears.
 
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A regear is planned, as well as a Metalcloak Game Changer 2.5 or 3.5, highline fenders and other supporting mods towards 37s.

Debating between a Super 30 kit with an e-locker...same thing I installed on my 97 TJ...or just buying a bolt on 44.

What I think you're saying is that the sensors are way out of their normal range and cannot operate correctly...hence the codes?

Basically the sensors count how many times the tire rotates and the computer does some math and everything squirts down the can bus to the speedo. I didn't think there would be an upper and lower limit to that range...and if there is one someone ought to be contacting JScan and having them add a warning or two to others.

I don't think a regear is going to fix ABS, TPM and key issues... would like to get to these codes sorted before tossing a lot of money at mods.

-Mac
 
The transmission shifts according the speed of the Jeep so if the speedometer isn't calibrated correctly then the transmission won't shift like it's supposed to. Then the tall tires and wrong gears make it worse, if you was to drive on flat roads all the time you might be ok for a while.

The TPMS is best just to delete it, most of us do that check our tires regularly.

The ABS could just be a wheel speed sensor and a scanner will tell the problem.
 
The transmission shifts according the speed of the Jeep so if the speedometer isn't calibrated correctly then the transmission won't shift like it's supposed to. Then the tall tires and wrong gears make it worse, if you was to drive on flat roads all the time you might be ok for a while.

The TPMS is best just to delete it, most of us do that check our tires regularly.

The ABS could just be a wheel speed sensor and a scanner will tell the problem.
It's a 6 speed...well more like a 3 or 4 speed unless I was planning on a Bonneville land speed record attempt.

JScan reports the codes seen...no more, no less.

I'll inspect the wiring...but I'm starting with a real key and a new stop switch.

Thanks!
Mac
 
It's a 6 speed...well more like a 3 or 4 speed unless I was planning on a Bonneville land speed record attempt.

JScan reports the codes seen...no more, no less.

I'll inspect the wiring...but I'm starting with a real key and a new stop switch.

Thanks!
Mac

Ok my JK had 35's on it when I bought it with a 6 speed manual and 3.21 gears. It was terrible with those gears and I very seldom used 6th gear. I put some stock tires on it and it's just like it's supposed to be, I already have to much in it to change the gears.
 
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