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Clayso, Master Automobile Technician
Category: Chevy
Satisfied Customers: 880
Experience:  ASE Master Certified Automobile Technician. 30 Years Experience.
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My 2009 Malibu periodically has a hesitation when I am

Customer Question

My 2009 Malibu periodically has a hesitation when I am driving. This mostly occurs in city traffic and sometimes on the highway at higher speeds. When at a stop it acts like it wants to stall out and sometimes does. The Service Traction, Service ESC lights come on occasionally when this occurs.
Have changed the transmission fluid, spark plugs and had a new sensor put in under the gas pedal. The car has 95,000 miles on it.
Any ideas what causes this. Of course when I take it to the mechanic it won't act up.
Submitted: 1 year ago.
Category: Chevy
Expert:  Clayso replied 1 year ago.

Hi Leann, I'm Clay a certified master automobile technician with 30 years of automotive repair and diagnostic experience.

Does the check engine light come on at any time?

Also have you mechanics mentioned any Diagnostic Trouble Codes (DTC)s? DTC's that start with a PO and 3 numbers and or a P and 4 numbers.

Some modules can send data messages to the Electronic Brake Traction Control Module (EBTCM) making it turn on the traction control and/or Electronic Suspension Control (ESC) lights. With your hesitation and stalling problems I'm sure there are existing problems and the mechanics just aren't looking in the right places.

Let me know.

Customer: replied 1 year ago.
Posted by JustAnswer at customer's request) Hello. I would like to request the following Expert Service(s) from you: Live Phone Call. Let me know if you need more information, or send me the service offer(s) so we can proceed.
Customer: replied 1 year ago.
No the engine light never has come on.
Expert:  Clayso replied 1 year ago.

The reason I ask is some driveability problems don't occur enough to set codes, but do cause issues like you are experiencing. Also I'm wondering why they would install an Accelerator Pedal Position Sensor. Is the shop you're using a driveability shop?

Customer: replied 1 year ago.
I don't know what a driveability shop is. This is the mechanic I use all of the time. Because the car would not act up after I took it to him 2x, he made this suggestion while not guaranteeing it would fix the problem. I will provide him with your response from your first e-mail and see if he thinks I need to take it to the dealer
Thank you for your help
Expert:  Clayso replied 1 year ago.

You're very welcome. Driveability shops have technicians with strong diagnosis abilities in problems like you're experiencing. Hesitation, stalling, no starts, computer control problems.... The hard part is getting the vehicle to act up when the tech is looking at data on a scan tool. Vehicles that don't set codes are the hardest. Your tech did the right thing by recommending a service with the understanding this might not be the cure.

I have a couple of suggestions for them to look at. The link below is a service bulletin from GM concerning a hesitation problem that maybe useful.

1. TSB - PI0090A Intermittent engine hesitation or flutter without Diagnostic Trouble Code (DTC) (inspect and correct intake camshaft position (CMP) sensor bank 1 connector terminals for intermittent conditions or poor connections).

2. Check and make sure there is no oil getting into the air intake system and contaminating the mass air flow sensor. If so GM has released an updated PCV tube and camshaft cover to correct this condition.

There were a couple more issues I've noticed with this vehicle, but there were DTC's present, where you have none.

I hope this information is helpful. If you or your technician have any questions or run into any problems let me know.

Kindly rate my assistance in a positive manner so I may have credit for helping you.
Positive ratings are greatly appreciated.