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OBD I codes 51 and 52 Info needed.

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So here's the skinny.

 

I've swapped a '90 EJ22 automatic engine into the rump of an '87 VW Vanagon. I know having just read that sentence you're probably thinking "post this in the Vanaru section"... Well, this thing runs great, and I'm just trying to get some more info on how the switches functioned when they were in their original enviornment so I know what I need to replicate to stop the last of my check engine codes.

 

I understand that 51 is the "inhibitor switch". I've done some research and found that the switch connects between the ECU and ground. What is the expected state of this switch? Meaning, when the ECU looks at this switch does it want to see a clear path to ground at startup and then no ground before the vehicle begins to move, or does it want to see nothing, then a ground just before moving?

 

I have the same question about the Parking switch ( code 52). This switch also attaches to both the ECU and ground.

 

For what it's worth I've gutted the reed switch and magnet from the Subaru instrument cluster and created my own VSS so the engine does in fact know when the vehicle is in motion. Hence no code 33.

 

I've searched over 13 pages of info without finding the specific info I am looking for. Any help would be greatly appreciated.

 

thanks in advance,

Jake

How did you wire up the ECU?

 

I'd suggest you read my swap write-up, particularly this blurb.

http://www.surrealmirage.com/subaru/swap/electrical.html#ecu

 

You need to make sure that the MT/AT identifier pin does not have a wire connected to it. That will set the ECU in MT mode. That should get rid of at least code 52. You may still have code 51, which relates to the neutral switch on the MT cars, however you could probably rig something up to make things work properly.

  • 4 weeks later...
  • Author

That's some teriffic information! I suspect I'll be able to resolve both of them with this stuff. Thanks a ton! The van just came back to me after a 3 week trip to Arkansas. I've only got a few days to work on it though. It's going to Colorado this Friday... Ah what fun.

 

 

How did you wire up the ECU?

 

I'd suggest you read my swap write-up, particularly this blurb.

http://www.surrealmirage.com/subaru/swap/electrical.html#ecu

 

You need to make sure that the MT/AT identifier pin does not have a wire connected to it. That will set the ECU in MT mode. That should get rid of at least code 52. You may still have code 51, which relates to the neutral switch on the MT cars, however you could probably rig something up to make things work properly.

  • Author

That got it! Thanks again for the info. I clipped the B48/20 ground lead. That took care of the automatic park code. then I fashioned a micro switch to the clutch pedal for the 51 code. Now when the clutch pedal is at rest there is a complete circuit to ground. When you engage the clutch the circuit is broken and all is right with the world. Connecting the green connectors shows steady "1"s. Kudos to you sir.

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