ECU codes - can anyone help or advise?

[chris79]

Got the following printout from my local garage as it's failed MOT..

DF006: Knock sensor circuit, open circuit or short circuit
DF057: Upstream oxygen sensor circuit, open circuit or short circuit
7G: Rear left hand wheel speed sensor circuit


In particular would the upstream oxygen sensor pinpoint if it's the pre-cat sensor or the post-cat sensor?.. will save me having to replace both.

7G is in relation to the ABS + SERV warning lights on my dash, suggesting a problem with the ABS sensor?.. but guy reckons when he spins the wheel he gets a 'pulse' from the ABS.. gonna take the wheel off and have a look I guess.

​Thanks

 

[M26]

Upstream oxygen sensor is pre-cat.

7G for me relates to - passenger air bag circuit resistance short circuit

 

[chris79]

Upstream oxygen sensor is pre-cat.

7G for me relates to - passenger air bag circuit resistance short circuit

Cheers for the reply.. hmm, well I've got ABS and SERV light on the dash.. have to suspect it's ABS?..

Also, could the DF006 code (knock sensor) be a result of the bad o2 sensor causing incorrect fuelling?...