Link CAN Lambda sensor failure

[DerekAE86]

The included sensor in the kit died today giving Error 54 / Excessive Pump Current.
The reading would be around a Lambda of 10.000 if it read at all.

But looking at the log it was also giving Error 24 sometimes. Was just curious what that error indicades?

The engine has been consuming a bit of oil so I'm about to rebuild it with new rings/valve stem seals etc.
So my guess is excess oil in the exhaust would have killed the sensor?

Though some insight on Error 24 would be nice just to make sure I'm on the right track and I don't have some other issue lurking.

[Adamw]

Error 24 means the current regulator has reached its limit, so closely related to 54.

[DerekAE86]

Ah ok. So this is just a internal failure of the sensor and nothing external in the wiring/power supply?

 

[David Ferguson]

It could indicate a wiring fault -- make sure you don't have a cable to the sensor that had rubbed against the chassis, or melted on an exhaust pipe.

[DerekAE86]

5 hours ago, David Ferguson said:

It could indicate a wiring fault -- make sure you don't have a cable to the sensor that had rubbed against the chassis, or melted on an exhaust pipe.

That would be between the Link CAN Lambda module and the Sensor itself yeah? Because it if there was a wiring issue between the CAN Lambda module and the body it's unlikely the module would detect or report back errors at all.

I still get Lambda Temp reported back and it still appears to be heating correctly (ramps up to 780ish quickly) so it doesn't look like a supply voltage/current issue.

[David Ferguson]

yes that's correct.  The error being reported is that the there is excessive pump current, so the wiring to the sensing element is drawing more current than expected -- bad sensor, or wiring shorted intermittently, I think those are the two choices.   I just suggest you check the wiring carefully before throwing a new sensor at it.

[Adamw]

In most cases error 54 will be a failed/contaminated/poisoned sensor. 

A quick explanation of how a wideband sensor works may help understand the terms "pump current" etc:

The main sensing part inside a wideband sensor is basically the same as you will find in a narrowband sensor, it is a ceramic material with a catalyst that generates a voltage relative to O2 content - but in both narrowband and wideband sensors this "Nernst Cell" is only accurate when the gas in the measurement cell is very close to stoichiometric - not useful on its own for wideband measurement.    So, for a wideband sensor they add an "O2 pump" to the side of the sensing cell, the controller then pumps extra O2 ions into or out of the sense chamber to maintain λ=1 inside the sense chamber at all times.    How much O2 the pump has to pump in or out of the chamber is directly related to the O2 content of the exhaust gas, the reported Lambda value that you see on the laptop screen is determined from the pump current that was required to keep the gas in the sense cell at stoich.  

"Excessive Pump Current" means the O2 pump is pumping as much O2 in or out of the chamber as it can, but the gas inside is not reaching stoich.  

If it is some sort of contamination, sometimes you can recover them by setting "Run when stalled" to yes and leave it powered up without the engine running for half an hour or so.