Really need your advice whether my daughters car is safe to drive or not as she needs to return to school later this morning

[tankueray]

Drive by wire systems usually have fail safes in place to prevent acceleration due to faulty readings from the IAC or MAP sensors; it's the whole CanBus thing, one computer refuses to work if another one is reporting an error or not reporting at all. If the ETC light was flashing, that's usually a sign of a "fatal error" for lack of a better analogy. It should have dropped into limp-home mode and refused to accelerate over 20mph (look in the owner's manual, it should explain it). These newer cars also don't have vacuum systems like you're used to, they use electricity (voltage, resistance) to sense and control most systems. That code explanation saying the word vacuum was a red herring, only the very expensive (i.e., tool truck) OBD II readers or the dealer/factory ones will expand to the real issue.

This is definitely related to the issue that the shop worked on, but that's not to say that they caused it. Most shops (and even dealers) just fix what the code tells them and don't do a lot of troubleshooting. You'll have to find an independent mechanic for that.

Before you spend any more money:
Being that it seems to reset itself after being shut off for a while, have them check for bad relays. Also have them check the throttle body for carbon build-up, check the battery connections, and replace the PCV valve and check it's connecting hose for cracks. I've fixed more gremlins on GM's with those couple of solutions than you can imagine....and they're really cheap.

If your weather is better than it is up here and you want to do it yourself before tomorrow, swap out the same relay from a known working system, like the A/C (check the fuse box diagram for locations and types), replace the PCV yourself, and take off the air cleaner, flip the throttle body flap and look inside with a flashlight. If there's soot, spray some B12 Chemtool in there and use a toothbrush if you need to scrub. Do not spray cleaner through the MAP like starting fluid on an old car, you will destroy the MAP, go straight to the throttle body. Also check the air cleaner shroud from the filter to the throttle body for any damage that might be letting extra air in.

But the real answer is the car just wants to go to College Station instead of Austin.
Good luck and Gig 'em.

 

[tankueray]

Also, are the symptoms (not just the light) only happening in stop-and-go/city traffic or does it also happen at highway speeds? I can't remember the function, but the mechanic should know, it's part of the emissions system and it usually doesn't cause a problem with mostly high-speed driving. I think it's the fuel tank carbon canister, EGR, and one other device on the top of the engine (along with the PCV) - one of those gets clogged or hasn't ever been replaced, it can cause those symptoms. (Note: EGR doesn't usually need replacing, the others are consumables.) The carbon canister is the first one I look at in a 4WD or vehicle that gets any off-road or dirt road use.

For future reference, check the cat and make sure it's still there too. That would cause the entire dash to light up, but nowadays it's a good idea to make sure it's there before you leave a car anywhere overnight.

 

[CliffordK]

She just got the jeep out of the dealer service department on Friday, 2/9/24 which they stated they had to fix the electronic throttle control.
...
The check-engine light came on Saturday morning [2/10/24]. I was able to get the jeep into a shop to run the error codes. These are the error codes:
-P0507: Idle speed performance higher than expected
-P2173: High airflow/vacuum leak detected

You need to check the codes again. It is quite possible the vacuum leak code went away. I had thought the idle speed was related, but it could be related to the electronic throttle control (or something else) that they supposedly fixed earlier.

As mentioned, and OBDII reader is fairly cheap and can be picked up at any auto parts store. The parts stores may even loan you one.

Unfortunately not all code readers are the same with some with more features and much more expensive than others.

-the engine light came on,
-the electronic throttle control system light was flashing red
-the traction control light came on…

You need to see the new codes. It almost sounds like an intermittent wiring fault to me.

Look for any abraded wires.

 

[tstex]

Thank you very much guys. Just got back from church.

A lot of good knowledge on these boards. The jeep is at a shop parking lot about 25 miles from home, so no overnight troubleshooting op’s.

I’m going there in the morning to ascertain if they can run a more detailed error code Ck. I’ll try to remember a lot of what was stated here so when i see the codes, might be able to connect some dots.

As far as symptoms, nothing from my daughter was detected at full Hwy speeds; only when the traffic slowed down to stop & go. I guess it was that momentary stopping that put her in pure idle mode. She said all was well until she hit 0-10mph traffic and after 10-15 mins is when the errors popped up on the dash and the initial 1 sec acceleration surge. She then drove 500 more ft b4 exiting and parking it. She stated nothing as acute as the 2 sec surge, but the next 500 ft & exiting the car “just didn’t fee right”…

I hope this encapsulates a description that makes sense.

Finally, going to CS would be much better. This daughter was going back to San Marcos.

Tstex
Class of 83

 

[Jstpssng]

dropped jeep off at credible auto shop

It's in the hands of the pros now. Hopefully they know what they are doing and the only danger remaining is to your wallet.

 

[Torvy]

Glad it worked out. I have a daughter at Tech and I drove my truck behind her car up there the first time. She drives our little 06 Matrix with manual everything. Good run around town vehicle. Lubbock is 7 hours away, so didn't want to risk it on the road.

Being a girl dad is hard. Fortunately, a guy in her friend circle up there is a mechanic. Just in case. She managed to shear a lug stud the other night, so off to the shop.

 

[2manyrocks]

The good news is your daughter is safe and hopefully, her jeep will get repaired so that she can depend on it.

 

[tankueray]

Finally, going to CS would be much better. This daughter was going back to San Marcos.

And she's still in school so there's still time to win the battle! Lol. (She's in good hands over there. One of the smartest people I've ever met and a great mentor went to SWT. Another good friend and smartest people I know was the head of the CS department at Texas State for a while.)

The thing I couldn't remember is the EVAP system, having run into similar issues across many GM models, albeit not drive by wire, I can almost guarantee the answer is one of those cheap parts or fixes. There seem to be universal issues across makes that come from the same few sources. I even had a similar issue in a brand new Hyundai (which is drive by wire) - I stayed the night with friends in the Woodlands, a week or so later, my car started freaking out, thankfully not trying to accelerate though, just surging then acting like it would die (totally used to this with the Yukon I traded in, so I was more pissed than scared). When I could get up to 60mph, it went away. After a few days it went into and stayed in limp home mode. I took it to the dealership, and a $500 soldering job later it turned out that rats had chewed the EGR wires that night in the Woodlands. They shredded my inner hood cover, I saw that the next day, I just didn't expect that they got under the engine cover. (Also, I keep a soldering iron in my car toolkit, so I was really pissed then.)

For quick reference:

• Electrical (relay, wiring to any of the below components, bad ground strap, or battery connections).
• EVAP System (carbon canister, PCV, EGR, canister purge valve, gas cap).
• Intake (carbon buildup in throttle body, cracked line/hose/housing that could let more air in/reduce vacuum).
• Least likely and most expensive: intake or exhaust manifold gasket, O2 sensor, crankshaft sensor, fuel system, or any faulty expensive component with a high hourly rate for R&R (unless it's a clogged or tampered with cat).
• Possible: any of the above if related to a previous repair, replacement, or aftermarket upgrade.
• Most Likely: Flux Capacitor - https://www.oreillyauto.com/flux-capacitor

A good mechanic can easily physically inspect or query the computer for issues pertaining to all the cheap fixes, but I'd expect them to take no less than a day to run through them all (4-6 hours).

Mandy
Class of '99

 

[tstex]

UPDATE #2: Hopefully the last one

The car repair shop in Katy Tx, the codes came back as a vacuum leak. They stated that there was a tear/leak in the hose near the PCV. You guys called it !!!! They ran a complete diagnosis on it w their computer and this seems to be the sole area of failure.

They said they had to order OEM/Dealer parts and was about a 2-3 hr wait. Stated with diagnostics, parts and labor, about $252 drive out. To get my daughter back to school safely, that's a pretty fair price to me.

I am still wrestling with the Jeep Dealership in her college town, and they are stating they have no record of her paid invoice or anything ?? My daughter paid cash to get our car last friday 2/9/24 at noon, so I am going to look into "who did what" and get to the bottom of it. She did not receive a typical service type invoice that shows parts, labor, etc, but rather a receipt print out as if you bought take out food.

Lessons learned:

-buy a good code diagnostic reader [any recommendations?]
-look at how to infuse smoke into closed systems to discern leaks in hoses/other
-have my daughter ask for more specifics on invoices and to always put your car invoices into an envelop that is stored in glove compartment. [does anyone store gloves in this area, or is this from Henry Ford's days] ;-}

I will post back after she makes the trip back to school and provide the results. Thanks again to everyone and safe travels to you and your family. best, tstex

 

[CliffordK]

Some dealer shops are very good. Others not so much. And error codes can always be a little cryptic to interpret.

Back to your original post.

-P0507: Idle speed performance higher than expected
-P2173: High airflow/vacuum leak detected

She just got the jeep out of the dealer service department on Friday, 2/9/24 which they stated they had to fix the electronic throttle control.

It is quite possible those are the same error codes that your daughter had when she went to the dealer.

So, fix the vacuum leak first then evaluate the idle speed performance.

The dealer may have done the work backwards, fix the idle speed, and ignore the vacuum leak.

And thus, they likely installed a part she didn't actually need.

I doubt you'll be able to claw back the payment.

Hopefully this afternoon her car will be fixed right.