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Ask sprinkles08 Your Own Question
sprinkles08, ASE Certified Technician
Category: Jeep
Satisfied Customers: 22655
Experience:  Chrysler/Dodge/Jeep Master Certified, ASE Master and Advanced Certified, Trans and Hybrid Specialist
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I have a 2012 jeep liberty jet, when I need to accelerate

Customer Question

i have a 2012 jeep liberty jet, when I need to accelerate quickly the etc (z)light comes on now if I accelerate gradually everything is fine. this happens daily. from what i've read online it might be the etc module
JA: Are you hoping to fix this yourself?
Customer: yes
JA: Great! What have you tried so far?
Customer: nothing, except looking online as to what may be causing the problem including possibly changing the throttle body completely
JA: Is there anything else important you think the Jeep Mechanic should know about your Jeep?
Customer: that's about it ive change the air intake to a larger dual intake but I don't see how that would cause the acceleration to be affected negatively.
JA: I'm sending you to a secure page on JustAnswer so you can place the $5 fully refundable deposit now. While you're filling out that form, I'll tell the Jeep Mechanic about your situation and connect you two.
Submitted: 1 year ago.
Category: Jeep
Expert:  sprinkles08 replied 1 year ago.

Hello and welcome to JustAnswer!

There are literally dozens of things that will cause the ETC light to come on. It's coming on because the powertrain control module is seeing an issue that will prevent it from correctly controlling RPM's and is setting a fault code. The first step in diagnosing the problem is to see what codes are setting. Do you know what codes are setting?

Customer: replied 1 year ago.
No i don't, the only light that comes on is the (z) z is a lightning bolt. I can go as fast as I want and can gradually get the even get the rpm's as high as it normally would as if I were to slam the gas peddle. It's when I actually need to accelerate quickly an d press the gas all the way is when nothing happens.
Expert:  sprinkles08 replied 1 year ago.

Do you have a scan tool or code reader? If not, do you have a big chain parts store such as Autozone? Most parts stores will read codes for free in the parking lot. The first step in diagnosing the problem is to determine what codes are setting and then testing can be done from there.

Customer: replied 1 year ago.
I don't have one and yes there is an autozone by my apt. The only problem is I'm at work now and won't be able to get there till tomorrow.
Expert:  sprinkles08 replied 1 year ago.

The first thing you'll need to do is determine what codes have set. I've seen issues with some aftermarket code readers not seeing ETC related codes for some reason, so it's possible that they'll tell you there are none found. Rest assured if the light is coming on then there are codes set.

As I mentioned there are dozens of possible causes for the light to come on. The problem may be with the accelerator pedal position sensor, there may be an internal failure in the throttle body (TPS, throttle control motor or physical binding of the blade), there may be something foreign blocking blade movement (which is something you can check before having codes read).

The problem may be a vacuum leak or intake restricted, or an incorrect perception of either. If there is truly an intake restriction or vacuum leak then the light will come on, but if the MAP sensor signal is inaccurate then it can set a leak or restriction code when there isn't actually an issue. Depending on what has been done with the air intake that may be an issue. If it is creating a restriction then the MAP signal won't match the throttle angle and a code is going to set.

The problem may also be with wiring or connections to any of the components, or an internal failure of the powertrain control module. It's possible that the problem could be in the PCM but it isn't that likely.