just as I pulled into work yesterday, my '03 230 slk engine started surging, the gas pedal would not respond, and it drove at about 20mph in a "limp home" mode. The trouble codes (2) read PO638 and PO120-where can I find a DTC list? Any help or ideads would be appreciated.

Thanks, Larry

 

Both Throttle pedal sensor/actuator codes.

P0120 Pedal circuit malfunction may indicate either a loose connection to the sensor at the pedal or more likely a failure of the potentiometer circuit within the pedal sensor.

This would fit with why you have no throttle response.

Could be other end (throttle butterfly) in which case water ingress comes into play.

Unless you are a DIY type suggest you cosy up to your MB dealer armed in your head with the cost of the two sensors and negotiate a deal based.

Before buying parts I would ensure that connections at both ends are good and that no corrosion / water is present.

Stuart

 

I could not find 638, I just scanned over it, but 120 has something to do with a pedal position sensor and problem is usually in the wiring. www.alldata.com is where I got this. this will help, however it has limitations. It is well worth the subsription. You ready need to know this car as best you can, unless you have deep pockets. I'm glad I've been lucky with my slk, cost wise, knock on wood. It sure is a funbucket of boltsto drive.