I jus started throwing a wierd group of codes and I dont really know where to go to solve the problem . It looks like I may have short to ground somewhere in the car . The codes are :

U0069 Vehicle Communication Bus E (-) Open
B2229 Air Bag Passenger Circuit Short to Ground - Loop #2

Those 2 will set within a minute of starting the car , and will reset within 10 minutes of clearing them . So there not random flukes .

This code just started coming up today .
P0121 Throttle Position Sensor/Switch A Circuit Range/Performance Problem

Any help on what I should do , or where I can look on the first 2 codes . I gotta assume , theres 1 shorted wire causing both codes to set ?

And on the TP sensor , does this mean the TP sensor is going bad ? Is bad already ? It just comes up in normal driving , in no kinds of specific situation . My idle has gotten "a little " bit rougher lately , but no symtoms while driving .

Sorry to the moderators if this shoulda been the General Cobalt forum . Due to wiring differences between models , I kinda wanted to throw it in the SS/SC section .

 

Have you been behind the dash at all? sounds like you (or someone else) installed something electrical and left something bare
I also guess that these codes might all be related inside the pedal
I would have a dealer look at it under warranty, if you are ok with that

 

I mounted 2 switches in between the radio and hvac panel to turn on my intercooler and fans about a year ago , but those are wrapped with electrical tape and have a convoluted tube from the point they enter the firewall all the way up to the switches . Their zip tied away from everything else , I didnt tangle them thru the rest of the factory wiring .

Im on my own , 44K miles =no bumper to bumper anymore.

Does anyone know where communication bus E is located ? I think the problem probabaly starts theres , and just effects the passenger airbag wiring , therefore causing that code too .

 

If you give me a few I'll go into dealerworld and pull up some info for you and some diagnosis charts

 

For some odd reason there was no information in SI about the two codes you have how ever there is one for the TPS code. Here check it out it could be the cause of you other codes as well.

Subject: Buck While Driving Stall SES Light Flash Door Locks Cycle CD Player Skip Clock Reset - keywords amp blown fuse ground idle inop inoperative intermittent L61 LE5 P0121 short STG surge trunk wire #PIC4252 - (10/05/2006)

Models: 2005-2007 Chevrolet Cobalt
2005-2006 Pontiac Pursuit
2007 Pontiac G5


The following diagnosis might be helpful if the vehicle exhibits the symptom(s) described in this PI.
Condition/Concern:

Owner complaining that the vehicle would buck while driving at times, may stall, ses light would flash, door locks cycle, cd player skip and reload, and clock reset to 12:00 It has been found that the Red/Black wire circuit #142 shorting on left rear inner quarter panel. It was not blowing the 50 amp maxi fuse right next to the battery in the trunk. This circuit feeds, hot all the time long term memory for ecm, tcm, bcm, radio, rcdlr. The wire is taped along with one other wire, the location is just to the rear of the subwoofer (must remove to access to remove trunk liner).

Note:: Your vehicle may or may NOT have a subwoofer, however the wiring is the same.
Recommendation/Instructions:

Remove damaged section of wire and repair, install insulation over edge of inner quarter panel, and install conduit..

Note: Please see SI-2000 Doc #1583102 for detailed wiring.

Please follow this diagnostic or repair process thoroughly and complete each step. If the condition exhibited is resolved without completing every step, the remaining steps do not need to be performed.


Here's a Schematic
http://service.gm.com/engif/000/001/582/1582415.gif

 

Thanks alot Blue . Your info "kinda of' maybe answered another baffling thought of why my car did what it tonite after I posted this . I though the air bag fuse was blown , it looked blown . But ended up not being blown . I dis-connected the battery to pull the airbag fuse , so I was fumbling around back there . Th battery was disconnected for about hour . When I reconnected , Im not throwing anymore codes . All 3 went away . Driving my car before I disconnected the battery , the idle would surge then almost kill the car , then go back and forth between like 200-800 RPM's , when I pressed in the clutch or put it in nuetral while the car was moving . Then when I stopped , the idle would drop so far it wopuld bout kill it , then pop back up to normal and idle perfect while the car wansnt moving . .....all thats gone now after dis connecting and reconnecting the battery .

Very odd , I hate problems like this .

 

Hmm, electrical gremlins are a bitch to troubleshoot. These cars especially with their networked systems are going to be real headaches.

Best advise I can give on this one is the dealer. I know you are out of warrenty, but electrical problems have very specific symptoms that are usually documented by the service providers. Like the post above, they may be able to connect your otherwise random collection of codes to a single wire somewhere.

Look where the light shines best. It's a phrase I learned when in mechanics school. You installed some switches. Trace all of that wiring completely and look to see if it has come loose or caused anything else to come loose.

 

P0121 Throttle Position Sensor/Switch A Circuit Range/Performance Problem

This is listed as: "Throttle Position (TP) Sensor 1 Performance" in the factory service manual -- 2.0L Engine Controls, Page 6-1060. It is more of an increased air flow detection and not specifically a bad throttle body.

Service manual says to check the following:
Vacuum hoses for splits, kinks, and proper connections
Air leaks at throttle body and intake manifold
MAP sensor voltage within specified range (0.8-4V)
MAP sensor change smoothly with increase/decrease in RPM
Inspect throttle body for
damage
broken shaft
drive mechanism

The other 2 DTCs you listed shouldn't have anything to do with the P0121