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Do CEL codes clear if you can't run engine, so just with IGN on ?


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I am sure I generated some codes by starting  up with TPS and MAP disconnected, then with them connected, drove mere metres with reconnected, then air temp sensor out of air box (air box removed to access O2 sensor plug for disconnect, then remove cat) Now with my crank but won't fire condition, CEL displayed a few codes with read memory plugs connected. I tried both sets connected and just IGN on to hear rad fans cycle, all sorts of clicking under the bonnet. It seems to have reduced a number of codes to just the air temp sensor code just with IGN on, rather than engine running (because it won't start :( ) 

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you do not run the engine to read codes... that is for clearing/resetting

to read - connectors connected, key on, engine OFF

if memory serves... green connectors will cycle all the solenoids & fans to check that all are functioning correctly.

Black ones are for reading the stored codes, again, with key ON, engine OFF

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and that is what I was hoping to do - clear/reset the memory, having read the memory with blacks connected and ignition on BUT I also have a cranks over but won't start issue , hence my asking if can clear the codes without starting the engine.

This is all after  I inspected the only cat just after the O2 sensor,  cleaned up three more grounding points (left chassis, front, right chassis, front and ABS pump bracket) All points sanded back to bare metal, all components cleaned up and sprayed with Chemtech 123 extra electrical cleaner and protector. I was in around the O2 sensor plug to disconnect it prior to the exhaust removal. Wondering if I have a sensitive wire in the loom out of ECU to the engine ....

PART_1679614657790_.jpg

Edited by Steptoe's photos
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7 hours ago, brus brother said:

while the test connectors are still connected will the car be prevented from starting??

no, it does not prevent it from starting...
the procedure to clear the codes does require the car to run with those connected.

 

@Steptoe's photos - disconnect the battery for about 30 mins or so - that will clear any stored codes
that is the only other way of doing it to my knowledge

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21 hours ago, brus brother said:

Been a while since i used those connectors BUT I may recall if while the test connectors are still connected will the car be prevented from starting??

Try to retrace your steps and get the connectors back to how you found them.

As heartless said , the process is three stages. First is connect black, THEN IGN only ON. reads from memory

Then with black disconnected, connect green, start her up, to read real time codes

Then, connect green pair, black pair, start engine , in order to clear the codes. I have found this can take a few minutes running before the codes cleared.

So, nope, having these plugs in any state is not gonna cause no fire up. 

Wondering if I can fit my EA82T between the chassis rails  :)

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Our Foresters never got EJ22, nor did main stream Impreza. After the EJ22 I think they went EJ20 for a while, then EJ25 in the Lib/Legacy line up - never really paid much attention.

The EJ25 are sort of known to need a new headgasket a bit more often than older smaller models.

I am gonna check all fuses and relays, get a NOID light set if I can find one that fits and works in Subaru loom.

I have every sensor except O2 for swap in diagnostics, every fuse and relay also, and an ECU :)

I even scored the ECU to sensors and injectors etc loom on the weekend - but they are a manifold off to swap , new inlet gaskets ...

This beast is heading towards it's own demise if things don't go right , very soon.

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The EJ251 is an awesome engine to run once you’ve swapped the HGs to the MLS type. 

The statement about needing HGs more often is bogus unless you keep reinstalling the factory part number referenced by the VIN. Using this part will just keep the same issues reoccurring. 

If your foz has the security system with the transponder component in the key you’ll have to find out if the ECU, transponder chip and security module need to be swapped as a group. Swapping the ECU could cause the engine not to start due to the security system. 

The EJ22s are available in Oz up to the last Gen2 Liberty model in ‘98/99. From there our Gen3 models came out with the EJ201 (from memory) and EJ251. 

Have you double checked the cam belt timing “to be sure to be sure”? 

Any vacuum leaks, cracked nipples on old van solenoids? Fuel tank purge solenoid working? I’m not sure where it’s located on your model Foz, on the earlier EJs they’re under the intake manifold on the RHS. 

Cheers 

Bennie

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I am thinking I may just have to check my work around timing belts done only 2,000km ago - if I were to chase random stuff. Done enough of that already I think. What I cannot fathom is all I do is clean up a ground, and I get a new issue on next restart (attempt) . I do like my diagnostic plug switch box - made life easier, so next job is to make a relay can checker box to plug those ultra reliable Mitsu 22A relays into

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