2006 KJ - ABS, Traction Control, ESP/BAS, Brake Light

jfitz93

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I’m going to start a new thread on this because I feel like I hijacked another thread by mistake. Sorry about that guys. I’m making this new one becasue I haven’t seen a thread that includes the brake light as well.

I recently bought a 2006 KJ that had the ABS, ESP/BAS, and traction control lights on. The Jeep drove like a top, didn’t have a speck of rust, 4WD was strong, and got a heck of a deal on it. I figured I could self-diagnose the lights and feel good about the deal.

Since the cheap-o OBD readers don’t read ABS related codes, I took it to O’Reilys to get a scan. Here’s the codes I got:
-C102B (ABS) “Right Rear Wheel Sensor Circuit”
-U1418 (ECM) “Implausible Right Wheel Distance Signal Received”
-C2102 (Steering Angle Sensor) “System Voltage Low”

I did a ton of research on the lights, mostly from this forum, and the first repair I landed on was the wheel speed sensors. I replaced both sides with OEM replacements and took it down the road a few miles but no luck. Second round of research took me to the wiring itself. I checked all wiring that I could get to and stripped away the protective plastic and didn’t find any rubs, kinks, or disconnections. Since I was getting code info from the right rear sensor, I went ahead and bought a new connector for the wheel speed sensor and spliced it in. Took it down the road, still no luck.

I still drive the Jeep occasionally, mostly on weekends, but don’t want to go to ******* it just in case it may further complicate the issues. Again, it runs like new. But recently, the brake light has also been coming on (the light that illuminates when the E-brake is engaged) and turning back off after some driving. I can’t find any info for the new symptom.

My next guess is maybe the tone ring is damaged or failed? I was also told on another post it could be the clockspring, but not exactly sure. Any help is appreciated guys thanks for reading.

-Jared


TL;DR - dash is lit up like a Christmas tree. ABS/ESP/TC issues. Send help or beer for the shop.
 

DadOSix

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So - liberties are notorious for electrical gremlins.

1st order of business -
System voltage. Anytime I see low reference voltages, i want to check the battery and alternator.

If sitting at 12v not running, and at least 13.5 or so, charging, then I figure on looking further.

2nd order. Get some grounds checked and established. A bad ground on a jeep will run you ragged.

Oem only for sensors, etc. imsee you are ahead of the curve here. i learned it the hard way, like most, with a wheel speed sensor issue on right front. A/z special was junk. Ended up replacing the hub and sensor as a unit.

On the wiring, it might LOOK good, but could be corroded with the 'green crusties' as Eric O. Of youtube's South Main Auto fame. He is a great diagnostic guy and general trouble-shooting tips.

If you have access to, or a buddy with a more detailed scanner / scope, you can watch the to e ring performance to determine if there is an issue at that point.

Keep diggin'!
 

lfhoward

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The brake light on the dash can also mean low brake fluid, which happens as the pads get worn down and the volume of the brake system increases. Check your brake pads— they might be getting thin and need replacing.
 

LibertyTC

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Could it be a bad ground wire at the parking brake switch itself hmmm..??
Call a dealer explaining your issues and ask if there was any recalls, or any KNOWN ABS ESP etc issues regarding these codes.
 
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Duster

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I have been through kind of similar recently. Here is my advice.

Take the right rear wheel off.
Take the 2 bolts out of the right rear caliper and pry the caliper up.
Hit the face of the rotor between the studs with a hammer a few times til you can slide the caliper off.
Look back in there for gunk, trash, etc.

You will see on the axle a thing that looks like gear teeth. That is the tone wheel for the sensor. Look around and down clockwise until you see the sensor sticking through next to it. 3:00 I think. If you haven't already found something, take the bolt off the back side that holds it in place. Push the red clip up in the connector. Press down on the black part of the top of the connector and pull the sensor out of the connector. If it won't pull out, go back to where you pushed the red clip up and take something and pry the black H up over the red and the sensor will come out. Trace the sensor wire as far as you can and check for chaffing. Also check your rear wheel bearing for play, especially if it looks like the tone ring has touched the sensor.

If you find nothing, just go buy one of these sensors. They are $20-$25. There is no way to test them like other sensors unfortunately. I suggest O'Riellys or Autozone for this purchase because their scanners pick up ABS codes as you know. Plug the new one in, bolt everything back together and go for a test ride. If it doesn't clear immediately don't fret. Drive it over where you bought the sensor and have them scan it again, like hey I bought this sensor here and it should have cleared the code in 100 feet.

Once they scan if they get the same, ask them to clear it. Drive around the block and if it sets again, go right back. Then you will have a fresh code list after the sensor install. If that sensor is still coding you know you have a wiring issue or issue with the ABS controller. If not you know that is good.

For the steering angle sensor, I swear I read a reset procedure somewhere for that once. Search for it. I think left twice back to center, right twice back to center. Can't remember.
 

LibertyTC

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That is some good information right there^^ = bookmarked.
I'm so glad My 04 KJ has none of this ABS, ESP/BAS, and traction control stuf to worry about.
 

DadOSix

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That is some good information right there^^ = bookmarked.
I'm so glad My 04 KJ has none of this ABS, ESP/BAS, and traction control stuf to worry about.
It is really interesting when it starts acting up! None on 04, but 06 has it on mine.

Other point of interest is when the esp system thinks you are skidding, it will throttle adjust and your jeep magically begins to slow down. Neat trick in traffic!
 

LibertyTC

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My Jeep doesn't even have tire pressure monitoring.
I do believe this is the reason I still have hair !;)
What ever happened to keep it simple stupid?
 

jimfry

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I’m going to start a new thread on this because I feel like I hijacked another thread by mistake. Sorry about that guys. I’m making this new one becasue I haven’t seen a thread that includes the brake light as well.

I recently bought a 2006 KJ that had the ABS, ESP/BAS, and traction control lights on. The Jeep drove like a top, didn’t have a speck of rust, 4WD was strong, and got a heck of a deal on it. I figured I could self-diagnose the lights and feel good about the deal.

Since the cheap-o OBD readers don’t read ABS related codes, I took it to O’Reilys to get a scan. Here’s the codes I got:
-C102B (ABS) “Right Rear Wheel Sensor Circuit”
-U1418 (ECM) “Implausible Right Wheel Distance Signal Received”
-C2102 (Steering Angle Sensor) “System Voltage Low”

I did a ton of research on the lights, mostly from this forum, and the first repair I landed on was the wheel speed sensors. I replaced both sides with OEM replacements and took it down the road a few miles but no luck. Second round of research took me to the wiring itself. I checked all wiring that I could get to and stripped away the protective plastic and didn’t find any rubs, kinks, or disconnections. Since I was getting code info from the right rear sensor, I went ahead and bought a new connector for the wheel speed sensor and spliced it in. Took it down the road, still no luck.

I still drive the Jeep occasionally, mostly on weekends, but don’t want to go to ******* it just in case it may further complicate the issues. Again, it runs like new. But recently, the brake light has also been coming on (the light that illuminates when the E-brake is engaged) and turning back off after some driving. I can’t find any info for the new symptom.

My next guess is maybe the tone ring is damaged or failed? I was also told on another post it could be the clockspring, but not exactly sure. Any help is appreciated guys thanks for reading.

-Jared


TL;DR - dash is lit up like a Christmas tree. ABS/ESP/TC issues. Send help or beer for the shop.
 

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Johnny O

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AutoZone does code scans with a good reader too.

I recently battled this nearly exact issue after destroying both front sensors while installing a lift.

Lessons I learned:
1. Gotta have good battery voltage. (13ish vdc at full charge)
2. There are quality control issue with ABS sensors right now. I went through quite a few before I got a good one. And no, it wasn't an expensive Mopar.
3. If you are seeing the unexpected distance code, I all but guarantee you got one of the bad ones...my Bert ground the face right off the hall effect pad outright destroying the Mopar and throwing the distance code on the Amazon special. The sensors that finally worked were a Duralast though the driver side was an Amazon cheapo.

Good luck.
 

Lobato

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This exactly thing happened to me today driving in the highway. All three lights came on, and all of the sudden off again. One thing I feel sometimes is that my ABS is kicking in too soon; I barely touch the brakes and I can feel the action of the ABS on the pedal. I feel like it could be a wore off brake pad, but I just came here to see that I am not alone with this issue.
EDIT: I plugged my OBD scanner and got the code U1417 and C1027 for the ABS. I believe both of them are pointing to a bad sensor on the rear left wheel.
 
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Johnny O

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This exactly thing happened to me today driving in the highway. All three lights came on, and all of the sudden off again. One thing I feel sometimes is that my ABS is kicking in too soon; I barely touch the brakes and I can feel the action of the ABS on the pedal. I feel like it could be a wore off brake pad, but I just came here to see that I am not alone with this issue.
EDIT: I plugged my OBD scanner and got the code U1417 and C1027 for the ABS. I believe both of them are pointing to a bad sensor on the rear left wheel.
Correct. You need a new sensor. Good luck finding one that works. Currently serious quality control issues across all brands.
 

jfitz93

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All right guys sorry for the long delay! Been working like a dog and getting paid like a pup. But finally found some free time tonight.

Put my KJ back on the lift tonight. In the past month I bought some new pads, rotors, spark plugs and coil packs. They’ve been collecting dust for several weeks while I’ve been working. Nothing related to the ABS issues but just some tune up maintenance that I’ve been wanting to do.

Anyway, when I was replacing the right rear rotor I took some time to check out the tone ring. Looked surprisingly clean and ship shape in there. No noticeable cracks or gunk stuck around it. As far as I can tell, the tone ring checked out.

HOWEVER, Since I had the Jeep on the lift tonight, I could get a really good look at the wiring back there (first time around, it was only lifted on a floor Jack so I couldn’t see much). I grabbed the multimeter tonight and tested the right rear connector. It was reading just under a half a volt. Tested the other rear, and it was testing from 4-7 volts or so. That led me to believe it can’t be coming from the module below the seat, it had to be isolated from where the wires split to both rear sensors and down to the right rear sensor. Ran up the wiring from the connector And I’ll be if I didn’t find just the smallest bit of chewed up wiring underneath one of the zip ties holding the harness in place. Wasn’t much, but I could see just the faintest bit of exposed wiring. It’s about 6 inches up from where I spliced the new connector in. I’m feeling hopeful that may be my culprit. I’m thinking of replacing the wiring all the way down. Any ideas on what size wiring?

Lastly, the brake light has went from coming off and on to full illuminated at all times. Parking brake is also not functioning. Parking brake cable looks good though. Not sure where to go on that one but I’m gonna tackle the new wiring first. Hopefully I get some more free time soon.

Appreciate all the responses!
 

JRB

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I haven't had this problem with my kj yet, but other vehicles with the brake light like that was in the brake pedal switch contact. Either a bumper pad rotted away never making contact with the switch, or issues with the switch itself depending how it's designed.

Usually when the pad deteriorates there's traces of it on the floor. Hopefully something that easy, or easier, as opposed to chasing around more wires ;)
 

jfitz93

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Update:

Restored power to the right rear speed sensor tonight! Man that felt great after weeks of chasing a ghost. Unfortunately, after driving down the road several miles my lights are still on. Interesting enough, the brake light did go out though…coincidental maybe? Idk, electronics are funny like that.

I’m going to go to O’Reillys to use their scanner to clear the ABS codes and see if thats all it might take. I’m really hoping so.

Will update again soon
 
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