05 cobalt is throwing 3 codes P0121 P0300 P0481
- Thread starter DreamerGT
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So you are getting:
1. P0121: Throttle/Pedal Position Sensor/Switch "A" Circuit Range/Performance Problem
2. P0300: Random Misfire
3. P0481: Cooling Fan Relay 2 Control Circuit Malfunction
Assuming they all appeared at once and the fact these codes don't seem to be related I might be tempted to check the health of your battery and connections (grounds?) for starters.
Otherwise, your PCM may be taking a dive.
1. P0121: Throttle/Pedal Position Sensor/Switch "A" Circuit Range/Performance Problem
2. P0300: Random Misfire
3. P0481: Cooling Fan Relay 2 Control Circuit Malfunction
Assuming they all appeared at once and the fact these codes don't seem to be related I might be tempted to check the health of your battery and connections (grounds?) for starters.
Otherwise, your PCM may be taking a dive.
The code P0121 and P0300 could be put together. P0121 is TPS sensor and P0300 is missfure detected. I would check the TPS, and the MAF, a dirty/bad MAF could cause the P0300as well. I'm not a big Cobalt person but maybe someone here can tell you.
The P0481 is the cooling fan circuit. IIRC it has two relays one for high and low speed fan. I might guess a bad relay for that.
The P0481 is the cooling fan circuit. IIRC it has two relays one for high and low speed fan. I might guess a bad relay for that.
Any other symptoms? Mileage?
Random thought, someone can correct this if it is way off base based on the codes, but on the fuse panel in the passenger front side, there are two large blue connections for the BCM wiring - supposedly these corrode after some time, and can throw off the GM Lan communication. A solution I've heard is disconnect the battery and remove and replace these connections a few times, cleaning up the corrosion/buildup on the pins. While you're in there and the battery is already disconnected, might want to pull fuse 25 and look for any damage, also another common one. In my case, I was getting a Power Steering message and finally my dash went haywire, and pretty much lost connection while driving once, was throwing code P0742.
Probably should wait until others chime in as well before you lose whatever is stored by disconnecting the battery.
Random thought, someone can correct this if it is way off base based on the codes, but on the fuse panel in the passenger front side, there are two large blue connections for the BCM wiring - supposedly these corrode after some time, and can throw off the GM Lan communication. A solution I've heard is disconnect the battery and remove and replace these connections a few times, cleaning up the corrosion/buildup on the pins. While you're in there and the battery is already disconnected, might want to pull fuse 25 and look for any damage, also another common one. In my case, I was getting a Power Steering message and finally my dash went haywire, and pretty much lost connection while driving once, was throwing code P0742.
Probably should wait until others chime in as well before you lose whatever is stored by disconnecting the battery.
Take it to the dealership
If it is simply throwing the codes but runs ok that does kind imply general electronic weirdness, and in a low voltage system reseating connectors and making sure everything is plugged in clean and dry is a good place to start. Cobalts have some issues with certain engine components depending on the year, model, etc.
I would pose this question on the internet and see if anybody has any idea of what it is. Some of the Cobalt forums especially.
You didn't give us much information about the situation with the Cobalt, model, miles, history, recent events.
I would pose this question on the internet and see if anybody has any idea of what it is. Some of the Cobalt forums especially.
You didn't give us much information about the situation with the Cobalt, model, miles, history, recent events.
Blast everything clean as the guys said.
P0300 sounds like an ignition coil failing, but I could be wrong. I think the 2005-up Ecotec got a completely different ignition system from the 2002-2004 Ecotec.
P0300 sounds like an ignition coil failing, but I could be wrong. I think the 2005-up Ecotec got a completely different ignition system from the 2002-2004 Ecotec.
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That 2nd one looks a tad shifty and I'd say the bottom one does too. They aren't awful though.
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