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Wideband readout not working
Sanzomat - 13/9/22 at 07:21 PM

Hi All. this is linked to another post I've just made in electrical about the regulator in my R1 4XV powered locost pushing out 14.8v.

I have a LD Performance wideband controller with a digital readout. Bosch 4.9 sensor. It worked fine for about a year then the readout started showing max (25.5 AFR) pretty much the whole time, occasionally showing a sensible reading of 12.5 or similar before going back to 25.5. It clearly isn't running at 25.5 AFR as it runs well. It is mapped open loop so the wideband is just for the gauge in use but it would be good to use it for tuning too. Tunerstudio is also showing the AFR as mid 20's so the digital readout matches, if not what the actual AFR is.

Recently (a while after it started mis-reading) I fitted an Acumen gear indicator with a voltage readout. Before this I couldn't tell you what the voltage regulator was giving but I now know it is 14.8v.

Today I noticed an odd thing. It seems my battery is on its last legs and after starting the car off jump leads, although the charging circuit is giving out 14.8v, while the battery was flat the juice going into the battery was bringing down the circuit voltage lower so say, 13.8v gradually increasing to 14.8v over a few minutes. While the voltage reading was lower, up until it reached about 14.6v, the AFR readout on the gauge was reading what I imagine to be correct - in the 11.9 to 13.5 range which is what it was mapped to. So, is it possible that 14.8v is too much for the wideband sensor or controller to work properly???

JAG - 15/9/22 at 07:16 AM

quote:

So, is it possible that 14.8v is too much for the wideband sensor or controller to work properly


Your anecdotal evidence suggests that this may be the case. Although it sounds to me like the voltage is affecting the sensor not the readout - I say this because you said Tunerstudio shows the same values as the Wideband readout.

I'd get the alternator/battery situation sorted and see what happens with the Wideband readout

[Edited on 15/9/22 by JAG]

cliftyhanger - 15/9/22 at 09:26 AM

Sensor worls on 10.8 - 16.5V (according to the datasheet)

I have a similar issue with an LD performance wiseband, similar age. All seems fine, then it flips to 25.5 and gets stuck for a bit.

I am going to invest in a new setip. PLX, AEM are the leading contenders so far. Not sure I want a display, but it is something to worry about....

coyoteboy - 15/9/22 at 01:17 PM

Automotive parts are almost always tolerant to much wider ranges than the base voltage (they have to cope with spikes of 50V+ from the ignition system), so I doubt it.

My experience with widebands is the sensors die, and it sounds like that here. Try unplugging the sensor and seeing if the readout goes to another value (usually 14.7:1).