Forums Forums (
-   Aura General (
-   -   Yet another Service ESC/Service Traction question (

MerrittK54 09-09-2017 04:38 PM

Yet another Service ESC/Service Traction question
Hi guys, we own a 2009 Saturn Aura 2.4L with 87,000 miles. Began having the Service ESC/Service Traction DIC messages with the steady SES light and constant traction light symbol last year. Engine misses and runs rough, but driveable. I also noticed that the fuel consumption is a little higher; no surprise there.

I have a code reader and it always shows P0201. We also have the Verizon Hum module, and they report the same P0201 code, but at other times they report P0301 and P0014. Last year I took the car to the dealership, and they replaced the intake cam position sensor. They noted on the service report that is the problem comes back that the throttle body would have to be replaced. It was better for a little while, but came back just as before.

Do you think I need to replace the exhaust CMP or the #1 fuel injector? Maybe the intake CMP has failed again? Any and all advice is welcome. I understand that a new throttle body is rather pricey.
thanks a bunch!

fdryer 09-09-2017 05:55 PM

Re: Yet another Service ESC/Service Traction question
In theory, a faulty throttle body would affect all cylinders together as opposed to seeing a single injector(#1) error code, P0201. If your Aura has drive by wire throttle, the electrically operated throttle does nothing but control air intake flow to the engine. With (presumed) dual position sensors (for safety), throttle actuators are controlled by the ecm. The electronic pedal sends signals to the ecm with the ecm commanding throttle opening. I'm no expert on EFI systems and wonder how GM(?) determined throttle body fault if replacing the intake cam sensor was P0014 related. Does your engine have variable valve timing? If P0201 remains, there may be a simple test requiring hands on troubleshooting.

If injector#1 is faulty, the engine should have a rough idle and run erratically. One way to verify injector fault - disconnect the injector connection and start up. Each injector tested should result in the other two or three cylinders still running. The faulty injector won't change engine running when disconnected from wiring. Since its 12v, disconnecting while idling won't present any hazard. If clips are used, removing all four will allow quick disconnect/reconnect otherwise plastic connectors may be difficult to unlock so care is needed to prevent damaging plastic connectors. Some familiarity is needed to disconnect one injector from power before trying to isolate one injector from others. At the least, injector#2 and #1 can be tested individually to see how the engine runs.

With the ESC and traction control indicators on, this may be a tell tale indication of a power problem - battery, their connections, drive belt and alternator. Has anyone checked battery voltage and alternator output? Is the drive belt tight?

MerrittK54 09-10-2017 06:43 AM

Re: Yet another Service ESC/Service Traction question
Thanks fdryer for the input. Do you have a procedure or know of a video for accessing and replacing the fuel injectors? I looked on Youtube, but to no avail.

I also see a number of videos having to do with cleaning the throttle body, but those who post them caution that if done incorrectly you can induce more problems.

fdryer 09-10-2017 07:47 AM

Re: Yet another Service ESC/Service Traction question
2 Attachment(s)
I have a drive by wire system and removed my throttle actuator for cleaning when replacing the #@$^&@(*@#$ thermostat buried in the 'V' section of my V6 engine. The only warning from service manuals is to refrain from drowning throttle with solvent. Small air passages may swallow solvent and enter into the electronics to create mayhem if not dried out before installation and use. I cleaned mine with a rag soaked in solvent, jammed a wooden handle to prop open the strong spring loaded throttle plate and scraped off hard deposits. The two injector rails with injectors were removed for access to the t-stat. If anything were to go wrong during t-stat replacement with almost all upper engine parts removed, I wouldn't be able to discuss anything positive about my experiences. Nothing went wrong except my sore lower back from bending over during the two day ordeal (I move slowly during complicated procedures so I don't have extra parts laying around).

While I do not have knowledge of 4cyl engines, a fuel rail is a fuel rail. This includes the injectors and associated wiring connections/harness. Once familiarized with upper engine layout, its just a matter of figuring out what needs to be removed for access to things and either taking pictures with a digital camera or cellphone to review later when mystery parts suddenly appear (immediately forgotten where they belong when removed). I wouldn't suggest performing anything above and outside anyone's skill level as each of us has limits on abilities. Discussions about troubleshooting possible injector failure is for advanced skills requiring some knowledge of EFI systems, fuel pressure awareness, electrical and mechanical skills as they are involved when meddling with our cars. If the two images are the same 2.4L engine in your Aura, the fuel rail is in the back between the engine and firewall. Not easy access for troubleshooting.

Are you able to make any initial assessments about battery/alternator voltages and drive belt tension? These might be the first things to check to rule out electrical issues before moving on to advanced troubleshooting.

MerrittK54 10-07-2017 10:40 AM

Re: Yet another Service ESC/Service Traction question

I may have solved my problem. Since my last post I have been making careful observations of the codes and when they appear. The two codes that show up 99.99% of the time were P0201 (fuel injector) and P0301 (#1 cylinder misfire). First, P0201 would show up and cause the ESC & traction control DIC messages to show up, along with the traction control icon. This was followed closely by the SES light, and code P0301.

So with nothing really to lose at this point, I went ahead and replaced all the spark plugs, and the #1 coil pack. After clearing the codes once more, I took it on a test drive and could not reproduce P0301 anymore. Maybe a coincidence, but the car did not act the same. I felt pretty good about knocking out 1 code for around $60.

Next, I did some more research into the P0201 code. One site I visited suggested checking the #1 injector for the correct resistance value. I couldn't figure out how to disconnect the connector from the #1 injector. This is where the photo comes in. This connector is where all 4 injectors meet electrically before the wiring goes elsewhere for the engine. I disconnected this connector and traced each individual injector to its associated pin and checked all the resistance values. Much to my chagrin, all 4 injectors ohmed out to the nominal value of 13.3 - 13.6 ohms. I was really hoping that the #1 would fail.

So, I figured I'd blow out both sides of this connector and put it back together. I found it difficult to snap this connector back together, which was strange since it came apart rather easily (maybe too easily?). But I finally heard & felt it snap. Just for good measure, I cleaned out the throttle body while I had access. I then put it all back together and went for a drive.

I am happy to report that we have driven the car for a week, and she runs beautifully (so far). I've read posts where others thought they had solved their problem, with their cars driving well for a number of days, only to have the same issues return. This may well happen to me, we will see.

My conclusion is that possibly the main injector connector may not have been completely engaged. Why else would it come apart much easier than going back together? And yes, I realize that I did a couple things at once, like blowing out the connector and cleaning the throttle body, and that those actions may have contributed. But like many of you, my time is limited and I didn't want to have to go through all this again if I didn't have to. Hopefully this is a final fix and that this might help others of you solve this issue!:yes::us:

fdryer 10-07-2017 05:18 PM

Re: Yet another Service ESC/Service Traction question
My guess is you lucked into a loosely connected O2 sensor. Hopefully, in the next few weeks without any more repeat of the same error codes, this solved the problem.

The main reason for these superbly designed plastic locking connectors may be to guard against heat, cold and vibration from allowing connectors to disconnect on their own to present mystery problems.

All times are GMT -5. The time now is 06:19 AM.

Powered by vBulletin® Version 3.8.9
Copyright ©2000 - 2018, vBulletin Solutions, Inc. The Saturn Enthusiasts Site.