clipse01

Hello,

I recently purchased a 2009 hhr 2.2 LT. The brake, abs and traction lights are on. The cars codes are listed bellow. I have replaced both the left rear and the right front wheel bearing and abs sensor. The mil status has not changed.

Codes
C0045 - LR wheel speed sensor malfunction
C0040 - RF wheel speed sensor malfunction
C0550 - ECU malfunction

Any ideas to how I may repair this system?

Thank you,
Gene

Oldblue

Welcome to the site, as you have found out it’s not necessarily the hubs, but could be other things.
Now that you have the codes, try a battery lobotomy.
You simply disconnect the negative terminal at the battery in the spare tire well for 30 minutes.
This will reset the computers in your car.
Drive it , if and when the MIL lights up again, get the codes read again, we’ll go from there.

clipse01

Thank you for your response,

I have disconnected the battery without luck. I have attempted to clear the codes with my scanner as well.

Thanks,
Gene

donbrew

Forget the ECU code for now?

Did your scanner get the hex number after the codes? (00, 0F, 18)

Could be the wheel speed sensor wires or the hubs or the connectors on the brake controller.

Do you have any idea of what kind of work was done before you got it?

donbrew

Here is the chart:

clipse01

Thank you for that info,

I hooked up another OBD-II and I now have more codes. The codes are as follows; C0201, C0550,C0045; C0040; C0201; C0550. Is there a way to test the harness? Do ABS modules often go bad? Where is the ground for the abs module located? Any other ideas?

Thanks,
Gene

Oldblue

It could be this little beauty right here, loose wires, or corroded connections

https://www.carid.com/2009-chevy-hhr...601973325.html

I used this for the pictures, it’s a place to have a look, it’s under the hood

clipse01

If it is the control module, does it have to be programmed to the car? If so, what is the most cost effective way of doing this?

Thanks,
Gene

Oldblue

According to this you’re gonna need to update the new module with GM software

https://repairpal.com/estimator/chev...placement-cost

donbrew

Did you start at the obvious, fuses and relays?

fuses #44, #57, #61 underhood fuse box.

Ground is at G111. https://www.chevyhhr.net/forums/how-...cations-56504/

I think it does need programming.

I'm betting somebody had it out and fudged the connector.