SCR (Diesel exhaust fluid) Equipment on Highway trucks.

Early SCR systems (Stage 1) had no NOx sensor, newer have, so SCR unit will apply more fluid, but if you add to much water SCR unit may store fault code.

do not use water. disitiled water only!

 

If the NOx sensor is left to fresh air what happens?

 

Fault code: NOx sensor reads implosive data.

 

But with newer trucks. Early stage 2 had not plasibility check.

With Mercedes engines I used to dump flash memory from SCR stage 1 units and reflash stage 2 units (keeping eprom data the same), but I got V6 dumps only, not for L6. I tried to use this dump on L6 but it missfires with wrong firing order

 

If the NOx sensor is analogue....would it be possible to send a different signal to the ECU....or if its digital parhaps the PWM could be changed?

 

NOx sensor got small electronic board inside that converts signal to linear voltage. When engine runs the output varies with correction cycle, like O2 signal on gas engines

 

That wouldn't be impossible to intercept/replicate to a friendlier result? Once you tell the ECU the NOx levels are okay it won't derate...is that how it works Pablo?

 

all depend on software. some ECMs are stupid, some smart (like on MX), but all they have some weak places

 

Is there a NOX sensor spoof or what ever you want to call it to send the proper signal to ECM?