Page 1 of 1

A couple more ecu questions

Posted: Mon Jan 12, 2004 2:23 pm
by camshaftprelube
First, i'd like to thank those who helped me out. I do have a couple lingering issues, though.

I keep getting codes for MAF and idle air controller. They have both been replaced with some used parts. It's no longer the "wrong Maf sensor" code but the "abnormal voltage" one. I'm assuming it's wired up wrong. Hitachi ecu and MAf, btw. I don't have my FSM in front of me, but I havethe Kennedy wiring instructions. Pin 8 on B58 is hooked up to pin 5 on the Maf, also. The kennedy instuctions are asking for a gray wire on pin 19, block B48, which doesn't exist. I think I saw some clarity in the FSM when I hooked it up, but there is still a problem.

Finally, I have a yellow/green wire coming out of pin 4 on F47. I can't figure out from anywhere what this used to be hooked to.

Posted: Mon Jan 12, 2004 3:50 pm
by Legacy777
Ok....either my fsm scans are way off for the ECU setup you have, or something is screwy....none of those show up....

http://www.main.experiencetherave.com:8 ... _page1.jpg
http://www.main.experiencetherave.com:8 ... _page2.jpg
http://www.main.experiencetherave.com:8 ... _page3.jpg

Re: A couple more ecu questions

Posted: Mon Jan 12, 2004 6:40 pm
by vrg3
camshaftprelube wrote:I keep getting codes for MAF and idle air controller. They have both been replaced with some used parts.
It may be worth cleaning your MAF sensor out. You could use brake cleaner (though it's hard to get to the sensor element on Hitachi sensors since it's shielded) or try swishing it briefly with isopropanol.
Pin 8 on B58 is hooked up to pin 5 on the Maf, also.
Good; that's important.
The kennedy instuctions are asking for a gray wire on pin 19, block B48, which doesn't exist.
This pin is meant to be connected to the braided shield around the MAF sensor power, signal, and ground wires.

Some cars didn't have it from the factory for whatever reason. Does your harness actually have a shield around the MAF sensor wires? If not, and if the harness runs near noisy electronics, that could potentially cause abnormal voltages on the lines. If you don't already have shielding around those three wires, you may want to get some.
Finally, I have a yellow/green wire coming out of pin 4 on F47. I can't figure out from anywhere what this used to be hooked to.
I've seen this wire on some Legacy harnesses too and was confused... from what I can tell, it goes out to the connectors which connect to the harness that's on the manifold, but I haven't seen any cars where there's a wire on the other side of the connector.

That pin is used on Legacy/Liberty RSes to monitor the intercooler pump, and it'd be a little weird if Subaru made the same pin perform different functions, so... I dunno. You're probably okay leaving it dangling, cuz I've seen several Legacies that appeared to.