whats the affect on the car if the ECU does not see this signal? Will it clear 1 or both of these errors in vagcom? 17841 - Secondary Air Pump Relay (J299): Open Circuit P1433 - 004 - No Signal/Communication 17840 - Secondary Air Injection Solenoid Valve (N112): Open Circuit P1432 - 004 - No Signal/Communication
No effect on drive performance but will affect cat light off performance ( tail pipe emission related as tested on the drive cycle). To be switched off in code as the engine no longer has these features.
It will clear error 17841. To clear 17840, leave the SAI solenoid plugged in, but not plumbed into to the EGR valve. You know the black vacuum resevoir with 2 solenoids clipped to it that sits under the intake? One of those is the SAI solenoid, the one on the left IIRC. There are a few errors that won't give you any long term trims. The SAI is one of them.
Or just get it coded out when you send your ECU away for a de-immob...Unless you are looking to do that properly also?
You can't code out the SAI on some ECUs. It couldn't be done on my model of MK5 ECU, so I had to fool it with a dummy load instead.
What is the ECU code that you speak of? I am sure all ECU power stages can be removed from the EOBD diagnostic fault table on Bosch controllers. I also am sure the feature can be disabled via the correct code word according to what I have seen in the ECU's logic. Can have a look later pending the VW software number. In the ECU which Dil was speaking of (022906022CP) most of the other codes I have switched off successfully ( i.e. for rear sensors, Cluster messages etc), but I missed the Secondary relay and pump powerstage codes.
I can't remember what ECU I had. I sold the car last year. I was told by the tuner I used that even if the SAI was coded out, you still wouldn't get long term trims. This is why I prefer to run a standalone and tune it myself. So called Motronic experts dish out so much contradictory information it's untrue.
The SAI or SLS system is part of the cat light off and heating feature and operates at engine coolant thresholds lower than when the fuel adaptives (Long term fuel trim for idle and part load) actually switches on. I would not expect the fuel adaptives to work during warm up and purge as the system will learn an error. In addition to switching off the fault codes associated with powerstage currant draw and component feedback in the EOBD feature, you can tell the system, the SLS components and feature is not fitted/available, providing the tuner in question understood the logic and knew the correct set of code switches to configure. Bosch "E-gas" ECUs are not so bad if you understand the logic which admittedly is not for everyone. The SEMs do simplfy the above significantly yes. No more torque structure to worry about. No need for rather expensive gear to flash or edit the cal and worse yet understanding where things are in HEX. Just fuel, spark, manifold switching and cam control on the 24v 022 motors Emerald K3/6 SEMs I have used seemed good enough for such a task!
