Richard

Hi All,

My SL55 check engine light came on, so I put it on Star Diagnosis and it shows the following.

P20BE-004 G3/4 (Right O2 sensor, before TWC[KAT]: Open circuit in sensor heating line (P0135)
P20BF-004 G3/3 (Left O2 sensor, before TWC[KAT]: Open circuit in sensor heating line (P0155)
P20C2-004 G3/6 (Right O2 sensor, after TWC[KAT]: Open circuit in sensor heating line (P0141)
P20C3-004 G3/5 (Left O2 sensor, after TWC[KAT]: Open circuit in sensor heating line (P0161)
P2026-002 Y58/1 (Purge control valve): Short circuit to ground / Switchover valve permanently open (P0445)

I find it strange that I have 5 different faults (and 4 similar), so either only 1 of them caused the Check Engine lamp, and the other 4 have been there a while or something more sinister (like engine management system) is failing.

The wiring for the before and after O2 sensors doesn't go to the same connectors as each other, only the power supply is common, but not same power supply for Y58/1 Purge control valve

Car is 7 years old, done 25K miles

Any ideas anyone ??

Thank you !

Richard

Ausmbtech

With the 4 o2 sensor codes I'd say the exhaust has been removed and the ignition switched on at some point in it's life. I'd clear all the codes and drive it for 2 weeks and see what comes back. I think they are older faults, the purge valve is likely to be the code that will come back.

Richard

Thanks I did clear the codes and all came back straight away car was driven

Do the purge valves fail often?

Richard

Richard

And the answer was ..

The Purge control valve (Also known as Regeneration valve) had failed and blown the fuse in the passenger side fusebox that powers the regeneration valve, the O2 sensors and a charcoal filter valve (can't remember what the additional fault code that came up was for that).

New fuse got rid of all the errors except the Purge Control Valve, new Purge Control Valve sorted that

And now the O2 sensors are working, I realise that it had been not performing as smoothly / well.

Cheers

Richard