I am having a real issue trying to diagnose thisknock sensorfault on my 2000SubaruEj251Outback
The code number is #22 with the CEL and terrible performance under load.
So to outline so far:
Tried newknocksensor, correcttorqueand alignment according to FSM – still light. Have checked both the old and newsensorsand both working correctly (Mulitimeter test confirmed this)
Have checked the continuity of the wiring from theknock sensorback to the ECU - all OK.
Checkedtiming beltall ok
Cleaned and checked theknock sensormounting face of the block several times
Checked all earths on block tochassis
CheckedValveclearances on heads
Checked correctinjectorplugs plugged in to correctinjectorsas per colourwiresin FSM
Compression test on allcylinders( all around 170psi and all within 10psi of each other)
Checked to make sure no loose items around the block knocking about
As far as I know theknock sensorwill throw a code if it detects improper ignition/detonation within one or morecylinders(so effectively the timing of theignitionof fuel and air). Basically the ECU has been told by theKnock sensorsomething is not firing correctly so retards theenginewhich results in poor performance.
Once I clear the code (by unplugging thebatteryovernight) as soon as I restart theenginethe CEL comes on immediately. (again always error code#22)
The van starts on thebuttonevery time and initially sits on tick over perfectly on allcylinders, revs up well and sounds good.(albeit with the CEL light on)
Am I right in thinking that once I have cleared the codes by unplugging thebatteryovernight, once I restart theenginethe ECU will start theenginein learning mode, it will push theignitiontiming to the point of knock and then limited it back to the correct timing level it deems to be optimum safe levels (although it will not throw a code/light in this learning process). Therefore why is the light coming on immediately I start theengineafter a reset?
The only other thing I can think of is if it related to a dodgycoil pack,ignitionleads orsparkplugs? Is it worth swapping this out or not?
Lastly it is annoying as **** to wait 12 hours with thebatterydiscounted every time I try something to clear the codes. I have read about FreeSSM with the correct USB/OBDconnector(seem onebaylink below ). Would this work or would a stand-alone reader be better (and if so which one).
I am sorry for the long winded email however I hope this detail might be useful in finding/solving this problem I didn’t have before I took theengine out.
I almost gave in and bought a new recondition block for stupid money thinking theengineis totally knackered/worn but I’m not going to give up on it just yet.
Any helps or anything I have missed would be great.
I am reading the code from plugging in the 2 x blackconnectorsand I am getting two long flashes from the CEL and two short flashes. This equated to error code 22 which I believe will readPO325using a scanner.
Just one that I am trying to the my head around and be clear on.
Does theknocksensoronly monitor for ignition/combustion irregularities or for other mechanical knocks as well including worn bearing/shimsect.
Knock Senor Error Issues
in 1990 to Present Legacy, Impreza, Outback, Forester, Baja, WRX&WrxSTI, SVX
Posted
The code number is #22 with the CEL and terrible performance under load.
So to outline so far:
Tried new knock sensor, correct torque and alignment according to FSM – still light. Have checked both the old and new sensors and both working correctly (Mulitimeter test confirmed this)
Have checked the continuity of the wiring from the knock sensor back to the ECU - all OK.
Checked timing belt all ok
Cleaned and checked the knock sensor mounting face of the block several times
Checked all earths on block to chassis
Checked Valve clearances on heads
Checked correct injector plugs plugged in to correct injectors as per colour wires in FSM
Compression test on all cylinders ( all around 170psi and all within 10psi of each other)
Checked to make sure no loose items around the block knocking about
As far as I know the knock sensor will throw a code if it detects improper ignition/detonation within one or more cylinders (so effectively the timing of the ignition of fuel and air). Basically the ECU has been told by the Knock sensor something is not firing correctly so retards the engine which results in poor performance.
Once I clear the code (by unplugging the battery overnight) as soon as I restart the engine the CEL comes on immediately. (again always error code#22)
The van starts on the button every time and initially sits on tick over perfectly on all cylinders, revs up well and sounds good.(albeit with the CEL light on)
Am I right in thinking that once I have cleared the codes by unplugging the battery overnight, once I restart the engine the ECU will start the engine in learning mode, it will push the ignition timing to the point of knock and then limited it back to the correct timing level it deems to be optimum safe levels (although it will not throw a code/light in this learning process). Therefore why is the light coming on immediately I start the engine after a reset?
The only other thing I can think of is if it related to a dodgy coil pack, ignition leads or spark plugs? Is it worth swapping this out or not?
Lastly it is annoying as **** to wait 12 hours with the battery discounted every time I try something to clear the codes. I have read about FreeSSM with the correct USB/OBD connector (seem on ebay link below ). Would this work or would a stand-alone reader be better (and if so which one).
https://www.ebay.co.uk/itm/Fits-Suba...m/323766582087
I am sorry for the long winded email however I hope this detail might be useful in finding/solving this problem I didn’t have before I took the engine out.
I almost gave in and bought a new recondition block for stupid money thinking the engine is totally knackered/worn but I’m not going to give up on it just yet.
Any helps or anything I have missed would be great.
I am reading the code from plugging in the 2 x black connectors and I am getting two long flashes from the CEL and two short flashes. This equated to error code 22 which I believe will read PO325 using a scanner.
Just one that I am trying to the my head around and be clear on.
Does the knock sensor only monitor for ignition/combustion irregularities or for other mechanical knocks as well including worn bearing/shims ect.
The car does not support OBD2, only OBD1