LSU 4.9 5 Wire

[Juergen]

Hello,

I have a Bosch LSU 4.9 with 5 wire connection. Unfortunately, it does not work on the Lambda Shield, the heater Led does not stop blinking. Is it possible to use it or does it have to be a LSU 4.9 with 6 wire connection?

Thank you!

[Christian_Bylund]

Hi Jürgen,

In fact, it is only the connector that has 6 pins. The sensor itself is only connected with 5 leads. The reason for this is that under a cover on the connector is a laser calibrated resistor that gives the shield its calibration data. This uses the missing pin. See the technical manual for more information regarding this.

Could you please post your output from the example code and I will try to troubleshoot from there. In addition to the output, could you please also describe how you power your Arduino.

Thank you.

[Juergen]

Hi Christian,
thanks for the quick response.
I connected a 12v 5A power supply to the lambda shield.
the output from the arduino serial monitor is: Status: 1,10495,452,867,782

best regards

[Christian_Bylund]

Hi Jürgen,

Somehow we are reading the wrong calibration information. This is usually caused by a low USB Voltage powering both the Arduino and the shields lambda controller. But we will try to sort out if that is the case or not.

It seems you are running the firmware for the GUI-Example code. Could you please replace it with the shields example code instead, it gives some more information for troubleshooting. Please find the code on GitHub.

Next I need you to have a look at the output. Here is an example on how it should look.

Code: Select all

Device reset.
Device ready.
Reading calibration data.
UA_Optimal (λ = 1.00): 303 (λ = 0.99)
UR_Optimal: 174
Heating sensor.
Measuring, CJ125: 0x28FF, UA_ADC: 857, UR_ADC: 130, UBat_ADC: 783, Lambda: Air, Oxygen: 21.07%
Measuring, CJ125: 0x28FF, UA_ADC: 848, UR_ADC: 165, UBat_ADC: 781, Lambda: Air, Oxygen: 20.73%
Measuring, CJ125: 0x28FF, UA_ADC: 847, UR_ADC: 176, UBat_ADC: 782, Lambda: Air, Oxygen: 20.69%
Measuring, CJ125: 0x28FF, UA_ADC: 847, UR_ADC: 175, UBat_ADC: 766, Lambda: Air, Oxygen: 20.69%
Measuring, CJ125: 0x28FF, UA_ADC: 847, UR_ADC: 175, UBat_ADC: 784, Lambda: Air, Oxygen: 20.69%

Please let me know the value of "UR_Optimal".

[Juergen]

hi Christian,

I loaded the sketch from Github.
The serial monitor now shows:

Device reset.
Device ready.
Reading calibration data.
UA_Optimal (λ = 1.00): 303 (λ = 0.99)
UR_Optimal: 174
Heating sensor.

The sensor gets very hot, but even after 10 minutes the display does not change.

[Christian_Bylund]

Jürgen,

The calibration data looks good. Everything there is as expected. Normally the sensors heats in 30 seconds. Try not to leave it longer than 60 seconds if it does not stop flashing the heating LED.

The threshold for when it stops heating and goes in to regulating mode is when the temperature value is below the calibration value of 174 in this case. Lower value is warmer. This never happens in your case it seems.

Looking at the serial data you posted from the GUI-Example code shows that the lambda controller thinks your sensor is cold "Status: 1,10495,452,867,782". Your supply voltage looks good 782 ADC which is around 10V loaded.

Before shipping we test the shields with a sensor of the type 0 258 017 025. What sensor are you using? Also have you double checked that all pins are connected correctly?

[Juergen]

Christian,

i have my sensor from *bay the name is : OEM-0258017025-Oxygen-Sensor-Lambda-5-Wire-17025-LSU-4-9-For-Bosch-Denso
it's a replica from China.
I checked the connections several times

I will get an original Bosch sensor and then contact me .

best regards,
juergen

[Christian_Bylund]

Hi Juergen,

Let me know if the new original sensor solved the problem.

Thank you.

[Juergen]

Hi Christian,

he original BOSCH sensor arrived today and works fine. thank you for your help.

best regards
Jürgen

[Christian_Bylund]

Great Jürgen, thank you for the update.