Car starts but runs really rough at idle and won't go when in drive. I put my reader on it and got P0113 and P0102 so I figured simple fix - needs new MAF sensor (my understanding is that the IAF sensor is built into MAF sensor). Put new MAF sensor in and no change. My freeze frame data is showing Fuel Press = 0, IAT = -40f, MAF = 0. Any ideas?
2011 CTS 3.0L P0113 P0102
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Service manuals are available from Helms, but they're expensive - nearly $500 for the paper version. There is a software service manual available online for up to 2009 model year, but that won't help you. I don't have any advice for how to troubleshoot an electrical problem without schematics.
You didn't post the miles on your car (an important detail) but it's 12 years old so probably high mileage. So your motor mounts are broken. Symptoms are the engine moves under torque, and vibration can be felt through the chassis at idle.
Also the transmission mount degrades, as does the driveshaft carrier bearing rubber isolator. I just include these as a point of information related to vibration, not necessarily the motor moving around.
You didn't post the miles on your car (an important detail) but it's 12 years old so probably high mileage. So your motor mounts are broken. Symptoms are the engine moves under torque, and vibration can be felt through the chassis at idle.
Also the transmission mount degrades, as does the driveshaft carrier bearing rubber isolator. I just include these as a point of information related to vibration, not necessarily the motor moving around.
I have no reason to believe your car is any different from all the other gen 2 CTS'. The motor mounts are known to fail. Why don't you post the miles on your car, you realize that is germane to the discussion?
Edit: the wiring harness chafe point isn't near the motor mount. I can't remember where as I dodged this bullet personally, might be behind one of the cylinder heads. There is a TSB on it.
I did replace the rear axle carrier bushing a while back - it was clunking, like the sound of a bad U joint when shifting into gear. I have 230k miles on the car and it has been remarkably trouble-free for the most part, just a few issues like wheel bearings, throttle body, water pump - typical maintenance.
At that mileage all the rubber components I mentioned need replacing, if they haven't been already. The motor mounts are oil-filled, although in yours the oil is long gone. You'll be amazed at the difference, but they won't fix your electrical problem. Presumably you've already replaced the timing chains?
It does sound like you're in need of the schematics and troubleshooting procedure, which I don't have for your model year. Maybe someone else has them? It's not that realistic to troubleshoot a modern car without appropriate tools and documentation. Good luck!
these cars don't have an issue with motor mounts but yours have been in there for 230K miles so they may (are) worn out by now...
the suggestions here are that the fluid filled motor mounts may be worn out and worn motor mounts may be the cause of your "rough idle"...through engine shake
good luck with your CTS
Bill
Yes, they do. This is well-known.
I wouldn't refer to the motor mounts as a problem, more of a wear item. Depending on the condition of the mounts on receipt and the kind of car you were transitioning from, you may, or may not notice the decline. When they're shot, an unmistakable vibration is usually felt while sitting idle while in gear.
If your scan tool is capable, check the following at warm idle; MAF flow (55 lb/min +/- 1) , Long term fuel trims (LTFT) (<10), fuel pressures- in tank (55-60 psi), high pressure (600 psi +/- 100 psi). The values in parenthesis are what I observe from my engine at around 185 deg coolant temp at idle. They are reference points for a start. If your idle readings of these values deviate by what can be considered an extreme amount it should clue you in to possible causes.
I figured it out after getting the wiring diagram. The was no voltage at the MAF connector so I chased down the ground and found that the cable had been cut. It’s a big thick cable that was cut clean. I haven’t taken a car in for work for 30 yrs, but I recently took it in to the local shop for an oil change because it was cold out and I was busy. Rat [email protected]$!s sabotaged my car!
That's insane, and to be honest a bit surprising. Wouldn't the (allegedly) nefarious mechanic realize your car wouldn't run when you came to pick it up, drawing suspicion? Are you sure it isn't the result of being pinched between the engine and the chassis when the motor moved under torque? I guess a clean cut would look different, but that is just so strange.
Just a ground cable, not a wiring harness bundle? That's nuts!
You're the one with the cable in hand, all I can see is an imperfect photo. You have to admit that seems like an odd thing for a shop to do while changing your oil. Chafing from engine movement? That doesn't look like wire cutters to me.
Wow. Just WOW.
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