[srt42]

Strange, I started the car and the engine was surging between 1000-1500rpm at idle. I had no throttle control, the ESP BAS light was on, along with the Service Engine Soon light. I drove it home from a relative's house this way and when I started it up the next morning, all was fine. I see a couple of other people have seen something similar. I hope it's a one-time occurence.

The only thing interesting that led up to it happening was the ESP kicked on several times due to slippery roads from rain, prior to parking it for a couple hours. I wonder if this is a flakey ESP issue?

Of course, in hindsight, I realize I should have shut the car off and then start it again. That seems to be the temp fix.

Code P2112: Electronic Throttle Control - Unable to open

 

[Rambit]

According to the service manual:

When the key is first turned to the on position, the throttle is closed and opened to test the system.

If the TP Sensor does not return to Limp Home Position at the end of this test, this DTC will set. One trip fault and the code will set within 5 seconds. ETC light is flashing.

Possible Causes are:

• THROTTLE PLATE STUCK AT OR BELOW LIMP HOME POSITION
• (K126) ETC NEGATIVE CIRCUIT SHORTED TO BATTERY VOLTAGE
• (K124) ETC POSITIVE CIRCUIT OPEN
• (K126) ETC NEGATIVE CIRCUIT OPEN
• (K124) ETC POSITIVE CIRCUIT SHORTED TO GROUND
• (K126) ETC NEGATIVE CIRCUIT SHORTED TO GROUND
• PCM

One of the pliminary things to do is inspect the throttle body for debris. Did you go into limp mode at all?

It's probably easier to attach this portion than to copy/paste everything.

Bernie

 

[srt42]

Thanks for the info Bernie! How was I supposed to identify Limp Mode?

 

[Rambit]

Thanks for the info Bernie! How was I supposed to identify Limp Mode?

Hi Brian. Here's an explanation of what Limp Home Mode is:

EMERGENCY RUNNING FUNCTION
In order to ensure a safe driving state and to prevent damage to the automatic transmission, the TCM control module switches to limp-home mode in the event of critical faults. A diagnostic trouble code (DTC) assigned to the fault is stored in memory. All solenoid and regulating valves are thus de-energized.
The net effect is:

• The last engaged gear remains engaged.
• The modulating pressure and shift pressures rise to the maximum levels.
• The torque converter lockup clutch is deactivated.

In order to preserve the operability of the vehicle to some extent, the hydraulic control can be used to engage 2nd gear or reverse using the following procedure:

• Stop the vehicle.
• Move selector lever to P.
• Switch off engine.
• Wait at least 10 seconds.
• Start engine.
• Move selector lever to D: 2nd gear.
• Move selector lever to R: Reverse gear.

The limp-home function remains active until the DTC is rectified or the stored DTC is erased with the appropriate scan tool. Sporadic faults can be reset via ignition OFF/ON.

I was just curious if you had gone into limp mode because you mentioned slippery roads that probably caused your tires to spin. Going into limp mode under those conditions is not unheard of and usually clears with restarting. The last sentence above explains that.

By the sounds of things I would say you can chalk this up to one of those "sporatic" things because I'm assuming all is back to normal now.

Bernie

 

[srt42]

Yeah, I agree, this was a sporatic event. The interesting part here is that ESP kicked on numerous time in my 15 minutes of driving the car that day and it was functioning normally when I parked it. The failure happened when I started it back up to go back home. It was stuck in an interesting mode. It stayed at 1500 rpm's and if you approached the appropriate speed, it would shift gears. I was definitely in a limp-home-mode.

 

[srt42]

Well, it happened again today. This time I turned the car off, restarted it, and it worked fine. I apparently have something starting to fail. This car has been rock solid and now this issue comes out of the blue.

 

[srt42]

It looks like TSB 18-035-05A might be the answer, which has been superceded by 18-018-06.

 

[srt42]

I took it into the dealer and at no charge, they performed the flash per 18-018-06. It fell out of warranty in May, so I was pleasantly surprised they did it at no charge.

He stated a couple of things I found very interesting. He stated that they performed the 18-018-06 flash and other TSB flash fixes to bring the car up-to-date. However, he could not provide the TSB's. He also stated that they no longer require you to experience a problem before having a TSB performed.

After having the flash done, I headed down the road and realized my Cruise control stopped working. I took it right back and they said they had to reread a flash for a different module to fix the problem that was introduced by the other flash. Very strange!! But, everything seems to be working now. Hopefully, P2112 will not rear it's ugly head anymore!