Replacing a Throttle Position Sensor on a Jeep Wrangler

It's always best to do any work yourself, then you can be sure it was done right, plus it will save you a considerable amount of cash. If at all possible, I try to do all required minor repairs to any of our out of warranty vehicles. In this case it's our 2003 Jeep Wrangler TJ.

The check engine light came on a couple of weeks ago with the code: PO122 (throttle body sensor/switch) 

Details:

P0122 - Set Condition: Throttle Position Sensor voltage at the PCM is lower than 0.1 of a volt for 1.3 seconds.

POSSIBLE CAUSES
TP SENSOR SWEEP
INTERMITTENT CONDITION
(K7) 5-VOLT SUPPLY CIRCUIT OPEN
(K7) 5-VOLT SUPPLY CIRCUIT SHORTED TO GROUND
TP SENSOR
(K22) TP SENSOR NO.1 SIGNAL CIRCUIT SHORTED TO GROUND
(K22) TP SENSOR NO.1 SIGNAL CIRCUIT SHORTED TO (K4) SENSOR GROUND CIRCUIT
TCM INTERNALLY SHORTED THROTTLE POSITION SIGNAL CIRCUIT
PCM

Step 1 Overview

This is a pretty straight forward replacement. I checked around with a few shops in my local area and the price to replace this part was anywhere from $100.00 - $180

Since replacing the TPS I've noticed an increase in MPGs (around a 10-15% increase) as well as better acceleration on hills and while passing.

Comments

[Ratfink4u]

Thanks for the helpful tips! My zip is back when mashing down the pedal and the over revving has quit! 12 mins start to finish!

[sdeberge]

2003 TJ w/ 17,000 miles and TPS problems: intermittent check engine light and the dealer wanted $225 to replace the TPS, so I bought one for $35 and did it myself.

Sent the first TPS back because the motor died unless I kept a foot on the gas, it shifted funny, and revved higher than normal before taking a long time to shift. It had none of these problems with the original TPS, just the occasional engine light.

Second TPS looks like its no good either. First start-up the engine ran at 2000 or so RPMs for a minute, then slowed to normal (the engine was warm). Once I started the test drive the engine died unless I kept my foot on the gas and has the same shifting problems. If I take my foot off the gas slowly, it will keep running but a really low RPMs.

The engine runs fine and there are no shifting problems with the original TPS back in there.

Any suggestions? Some blogs say that OEM is the only replacement part that will work right. Other blogs say you have to disconnect the battery overnight to re-set the engine control module so it will learn the new TPS. I didn't turn it clockwise to set it in place - could skipping that step cause the starting position to be off and result in these problems?

[gdhenson]

Non OEM is fine. That is what I put in mine. The only reason you needed to turn it counter clockwise what to get the metal bit to fit in the slot, if it fit without turning you should be fine. A 5 minute battery disconnect is all you need to reset all of the computer data.

Are you getting any codes or is the check engine light coming on? In the meantime I run this by my buddy that is a local mechanic and see what he says.

Also, I'm a member of a Jeep group here in St Louis that is a wonderful source of information. Everyone of the message boards are helpful and we have numerous mechanics in the group.

http://www.midwestjeepthing.com/

[melissaalexander]

I have a 2004 Wrangler that I bought 8/18/11. Daddy replaced the TPS 2 wks after I got it. Having issues again, but this time I will be replacing w/your assistance! Thanks for posting the instructions!

[gdhenson]

Feel free to ask if you have any questions. I've owned Jeeps since the 80s, I might be able to help you

[atombomb1945]

Not only do I have the same model and year Jeep, I also have the same issues you describe here (RPM's race, pain to pass someone on a hill, idiot light keeps coming on). I have asked friends and mechanics on this issue, and no one has been able to figure it out. One shop told me that I would have to do a few hundred $$$ worth of work. Now, thanks to you, I have a better idea of what to do and where to look. Awesome.

[gdhenson]

Very cool - I hope this helps. Feel free to post any questions you might have. I'll be replacing the A/C blower resistor this weekend and will post a new instructable for that. I also have the photos for adding new sway-bar linkage, I'm working on the instructable for that today.