Codes P0123, P0223 and c342d, no crank, no click, no start issue?

AMANTHA ANDERSON

MEMBER
2009 CHEVROLET COBALT
2.2L
6 CYL
2WD
AUTOMATIC
25,000 MILES

My car listed above would randomly go into limp mode, but I could clear the codes and restart. I replaced the throttle body in May, then the radiator, radiator fan, and then jumpered the cooling fan relay.
The car went into limp mode and wouldn't come out, disconnected battery and came back later, it wouldn't start. Turn to acc lights come on, turn to crank and nothing. Checked battery, fuses, relays but they're all good. Could jump the crank relay and force it to turn but it wouldn't run. Then I noticed the security light was on steady and sure enough the transponder had fallen out of my key.
Now I got into an accident a month ago, part of a tree-bush got wedged between driver's door and front fender, and since then I've got no A/C in Phoenix in the summer, and I've been Duke's of Hazarding it in and out the driver's window. So, I was pretty sure I wanted to set my car on fire at this point. But I got lucky(?) Yesterday when in a last-ditch effort, I dumped my purse out and found the transponder chip.
So, I taped it to the excitor and banged the driver's door mostly into shape so as to be able to open and close it again. Then I spent hours sweating and upside down, checking wires and cleaning grounds, to no avail.
The security light is off now. The battery is good, I've got power to the fuse box, I've triple checked the relays, but I still have no click no crank no start.
The only DTCs are the same ones I've been getting: p0123, p0223, and c342d. Which apparently just means I've got a cheap, crappy scanner.
However, in the freezer frame data today I saw that I'm getting ghost readings on throttle and accelerator (should have been zero) with a fluctuating TAC.
My brain is fried right now, admittedly, but tell me I don't have a garbage ECU.

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3 Replies

JACOBANDNICKOLAS

MECHANIC
109,724 POSTS

Hi,

Sounds like you've been through a lot. As far as the no-crank condition is concerned, we need to do a little checking.

First, see if it will start if you put it in neutral. If there is no change, then I need you to check for power at the starter.

At the starter, there will be a heavy gauge black wire that has power at all times. There will also be a smaller gauge purple wire that only gets power when the key is in the start position. I need you to check if that wire gets power when a helper turns the key to the start position. If it does, replace the starter.

Also, confirm the crank fuse and relay in the under-hood fuse box are both good. When you check the fuse, also confirm there is power to it. As far as the relay, if there is another one in the box having the same part number, switch them. If there isn't, here is a link that explains how to test the relay and circuit.

Here are two links you may find helpful:

https://www.2carpros.com/articles/how-to-check-an-electrical-relay-and-wiring-control-circuit

https://www.2carpros.com/articles/how-to-check-a-car-fuse

Let me know what you find.

Take care,

Joe

See pics below. Note: Pic 3 shows the locations of the fuse and relay in the under-hood fuse box.

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