Landracing Forum

Tech Information => EFI Questions => Topic started by: oz on June 01, 2011, 04:35:55 PM

Title: Wiring A Wideband o2 sensor
Post by: oz on June 01, 2011, 04:35:55 PM

I have just started wiring up the bikes injection controller DTA S40 and it only accepts 2 wires into the unit for the lambda yet the recomended O2 sensor has 4 wires,1for signal 1ground 2 others these are presumably for an internal heater element, is it nescasary to have the thing heated or not, if so anyone got a sketch or wiring diagram for the thing.and does it need a control unit or just an input voltage,if so 5v or 12v

do these things make voltage just from heat,,,,, hmmm clever

Cheers Oz

Title: Re: Wiring A Wideband o2 sensor
Post by: BVCBR on June 01, 2011, 05:35:23 PM

I haven't found an installation manual on the S40, but I would bet it's the same as most other systems that can use a 0-5 volt signal from an external wide band controller. You would buy something like an AEM, Dynojet, Innovate, etc. wideband kit and connect the analog (0-5 volt) signal to the Lambda and signal ground input of your S40. You would then need to set the calibration in the ECU to match the wideband kit output.

If you have a 4 wire sensor, it is a narrow band sensor that has signal, ground, heater 12 volts and heater ground. This will not work well if the ECU input is intended for a wideband signal. The narrow band has a 0-1 volt output and is very non-linear. Its ideal working range is approximately 13.8 to 14.8:1 AFR. Beyond that, they roll off very quickly on volts vs. AFR. Most Wideband kits have a 5 wire sensor and may have a mating connector that has 7 wires due to a calibration resistor located in the sensor connector. They usually have a range from around 9 to 25:1 AFR, depending on sensor manufacturer.

Now, if they recommended the 4 wire, that would mean they don’t use a true wideband input. On most 4 wire sensors you will have 1 black, 1 white and 2 grey wires. The black is signal ground; the white is signal; the grey would go to switched 12 volts and a good power ground. Polarity is not important on the grey wires. The switched power will need to be able to handle about 2-3 amps current draw for the heater.

Title: Re: Wiring A Wideband o2 sensor
Post by: nrhs sales on June 01, 2011, 06:09:09 PM

Pretty sure the extra 2 wires are for heating like you said.

Title: Re: Wiring A Wideband o2 sensor
Post by: oz on June 02, 2011, 01:12:26 PM

I rang DTA today and apparently you wire it to 12v switched supply and job done the ECU then receives the required info/voltage, seems a bit strange but that will do me,
I really didnt want to go for a seperate unit just for the Lambda.

thanks fellas

Oz