I purchased a 2007 Jeep Grand Cherokee Laredo at a large dealership on Tuesday. Leaving the lot I got a check engine light and the tire pressure warning light. Took it back and service dept reset the code. The dealership replaced the throttle body when they serviced it on trade in according to Carfax.
Drove 5 miles home and lights came on again. Called and was told to bring it the next morning. I took it back and after 4 1/2 hours they told me to come back the next day because they ordered the wrong parts.
Went back on Thursday and they replaced 4 TPMS sensors and the solenoid. Total cost of $1300 no charge to me. Drove 4-5 miles and parked, Got back in about an hour later and within one mile the lights came on.
Took it back in to the dealership on Friday and they reset the code again and test drove it “up to 50 mph” and no lights. I left again and drove about 10 miles and the lights on.
So after replacing the throttle body and solenoid any ideas? The dealership is not happy and I won’t find out if they will do anything else until Monday. I’m not sure what to look at next so anything from you would be appreciated.
P0507 refers to the Idle Control System RPM being lower than expected.
Don’t believe Carfax. They provide more bogus information than Satan. Have serious doubts that the dealership replaced the throttle body. And if they did, it was probably the wrong part.
They replaced 4 TPMS (Tire Pressure Monitoring System) sensors? Why?
And a solenoid? What solenoid? Why? Was it the Purge solenoid? The Exhaust Gas Recirculating System solenoid?
Here’s my suggestion. Have the codes read by a reputable shop and post them all here.
I got a real bad feeling about this one. I fear you may have a purge system problem, which might be expensive to repair (it purges HC vapors from the charcoal canister, and those things are expensive), but I think a new set of codes is warranted. I wouldn’t trust the dealer that sold you the Jeep. I suspect they know what’s actually wrong and are “brushing you off” 'cause they know it’ll be expensive to repair.
Beyond that I got nothin’. Anybody else?
PostScript: if the future it would be wise to have any used vehicle you’re considering thoroughly checked out by a good test drive and an independent mechanic before signing anything.
They replaced the tpms sensors because the warning light was on. First flashing and then solid. The solenoid was Part number: 52090419aa which comes up solenoid purge valve.
I’ve taken it to Autozone a few times. The one before they changed the solenoid was Idle Air Control Higher Than Expected. The two autozone scans after the solenoid repair says I need to replace the throttle body.
I fully agree I messed up here but hopefully I can get it right now.
Thanks again everyone.
p.s. Looking around for symptoms of purge system problems I found difficulty starting as one of them. One of the Autozone guys and one of the intake guys from the dealer have commented on how touchy the starter is. It is very sensitive and starts with the slightest touch. So no problems there. It actually runs well enough. Idles in park around 800-900.
Today I had to do a u-turn and had to reverse to line up and the truck hesitated when I pressed the gas before engaging and again when I put it back in drive. Don’t know if that’s normal for Jeeps though. I also felt it hesitate once today while driving.
p.p.s. Could this error code P0507 be dangerous at all while driving? And is there any way to scan the vehicle for a history of codes and resets? To see if they were actively hiding this?
The most common cause of a P0507 code is a vacuum leak, usually somewhere in the intake manifold. When there is a leak somewhere in the intake manifold, it causes a different fuel/air mix for some cylinders than others which causes the idle to be higher. You usually get a slightly rough idle but you would probably have to had experienced the vehicle before the leak to notice the roughness.
The dealership should be able to track down the vacuum leak fairly easily. Also it could simply be a mis adjusted throttle stop screw or gunk build up on the idle control valve stem.
Good ideas above. High idle speed problems can be difficult to track down. There’s a lot of different stuff that can cause that symptom. The tire pressure issue isn’t related, but the purge valve could be. PCV system problems can cause it too. So ask you shop to double check the purge valve and pcv systems are working correctly. If they are, they’ll have to determine if there is any unmetered airflow getting into the engine, the brake power booster is a common source for this, and that the throttle valve is moving freely, and not sticking b/c of pcv or egr gunk built up on the backside. Some vehicles host a separate device called the idle air control (IAC) and if yours has one, it should be a suspect too. My Corolla had a high idle problem a while back and after a lot of wondering, I finally traced it to the idle air control. Another idea, If you feel lucky, replace the thermostat. If the engine coolant isnt’ getting as hot as it should it will cause the idle rpm to be too high.
If the selling dealer is trying to solve the problem it would not be a good idea to involve another mechanic. That might give them reason to stop working on it. Also you might calmly talk to them about possibly taking it back and letting you choose something else from their lot.
That’s the thing though. They’ve had it in the shop 4 times over 4 days and the problem isn’t fixed. Three of those times all they did was reset the CEL and send me on my way. I’ve sat in the waiting room for over 8 hours last week and still nothing fixed.
Not sure taking it back a 5th time will do other than delay me until the loan gets finalized,
