Replaced CPS. Idles fine, but dies immediately under load. Have scan stats.
 

Hello,

For a week my 04 coupe w/52k had been stalling after 10-15 minutes of driving. It would crank, but not restart. After an hour of cooling down, it would start with CEL, but would only run another 5 minutes until it died again. Code was first P0410, secondary air injection system, then a few days later P0335, for CPS.

I got a Duralast CPS from Autozone. The harness plug doesn't click into position like the stock one did; it in is position, but takes little effort to pull off. I bought a K&N recharge kit and soaked the filters pretty well and followed the provided instructions. Bought used; it came with some blue Septre cone air filters.

After install, started right up with no CEL; cleared the ESP light with wheel rotation. It ran idling for a good ten minutes, but as soon as I was in gear and tried to accelerate, it got a CEL and died. I tried this a few times with the same outcome.

I bought an Autel MS310 scan tool. The freeze frame says:

DTC freeze frame - P0335
Fuel system 1 - CL
Fuel system 2 - CL
Load value (%) - 31.4
Engine coolant temp - 187

Short term fuel trim 1 (%) - 6.3
Long term fuel trim 1 (%) - 0.0
Short term fuel trim 2 (%) - 6.3
Long term fuel trim 2 (%) - 0.0

Intake manifold absolute pressure - 12.1
Engine RPM - 2150
Vehicle speed MPH - 11

This is a great site and I have benefited from it for two years. Thanks for all of your support to the community!

Re: Replaced CPS. Idles fine, but dies immediately under load. Have scan stats.
 

I am going to go out on a limb and say replace the CPS again with one that fastens correctly. I have used the Bosch and a Napa one that is identical (but no MB star) and have had no issues with them. Your connection may be going bad on you when it gets hot...:( I fought this battle for quite a while previously...:mad:

Re: Replaced CPS. Idles fine, but dies immediately under load. Have scan stats.
 

I bought one from Advance Auto Parts and my car would quit at 5000 rpm, more or less. Idled better than ever. I put the Bosch back in and it runs fine now.

Les

Re: Replaced CPS. Idles fine, but dies immediately under load. Have scan stats.
 

Thank you for your prompt responses!

I will get a new CPS from Napa; I actually went there, but they were not in stock and sold for $87. Autozone had them in stock for only $55.

Not sure where to get a Bosch, except...Amazon for $39? Bosch 0261210170.

Amazon.com: Bosch Mercedes Benz Crank Reference Position Sensor: Automotive

Re: Replaced CPS. Idles fine, but dies immediately under load. Have scan stats.
 

It sounds like Bosch was the original part - I think I'd go with a Bosch.

... and it's about time for me to order one.

Re: Replaced CPS. Idles fine, but dies immediately under load. Have scan stats.
 

Bosch $47.70 shipped 3-5 days from Amazon.

Re: Replaced CPS. Idles fine, but dies immediately under load. Have scan stats.
 

The NAPA part is a Bosch also.... all numbers are the same as OEM... just no MB star... yes they do run a little higher than other places.... but when I needed one they had it in stock!

Re: Replaced CPS. Idles fine, but dies immediately under load. Have scan stats.
 

Update: Installed Bosch CPS. Everything is great! Thanks, everyone!

Re: Replaced CPS. Idles fine, but dies immediately under load. Have scan stats.
 

Mike, any leak at all on the CPS will make her not idle and run rough...finally die...glad you figured it out.