[Paul]

ive read about you guys getting codes and what not from your ECU and im wondering how i would go about checking my ecu because im sure i have some problems to get sorted out

 

[Dren]

it should flash the code when the ignition is turned on. it's a red LED that flashes on the top of the ECU. you should see it flash once when the car is turned on. then if the ECU is throwing codes it will show you them

your check engine light will also be on if the ECU is throwing codes.

 

[Paul]

the check engine light has ben comming on for about a week now

 

[downest]

If you have OBD0, pull back the carpet on the passenger floor and you can see the ECU LEDs. If you have OBD1, jump the connector under the glovebox area, it's blue with 2 pins, and your CEL will flash the code.

 

[Paul]

how exactly do i read out the codes by a flash of an LED

 

[downest]

I believe it's in chapter 6 of the manual. Count the blinks, a long blink means 10, and the short are 1, just add them up.

 

[Dren]

If you have OBD0, pull back the carpet on the passenger floor and you can see the ECU LEDs. If you have OBD1, jump the connector under the glovebox area, it's blue with 2 pins, and your CEL will flash the code.

i have a pm6 ECU but i also have a blue connector with two pins hanging there

 

[mattminerDOTcom]

yeah, on your car its just a timing jumper, to bypass the ignition values coming from the ecu. on obd1 and up cars it does both.

also, if you are obd1 that jumper doesnt necessarily work, it depends on how the person made your harness.

anyway, yeah on our cars just count the flashes. short flash = 1 long flash = 10. it pauses then displays the next code.

[email protected]

 

[Paul]

alright so i pulled back the carpet in the ol' hf and found a bigas metal plate with a lil hole wich had hte led in it.. so i turn the key on it blinks once then all it does it blink 12 times pause blink 12 times pause and so on and doesnt stop soooo do i have a code 12???? or is it just retarded

 

[downest]

Yes, you have code 12, which I remember from the HF is EGR.

 

[mattminerDOTcom]

thats odd, it shouldnt be blinking 12x. pull the 'backup(i think)' fuse under the hood (not the ECU one) in the shock tower fuse box. that should clear your codes. then see if they come back and check again.

[email protected]

 

[rex2nr]

Matt means the "hazard" fuse underhood

 

[bobski]

thats odd, it shouldnt be blinking 12x.

Why is that? Most OBD-0 ECUs don't make use of the long blink. The HF does have an EGR system... What's the problem?

 

[toxiclows]

yeah it is the hazzard fuse....

 

[Paul]

what is an EGR system?

 

[shadowcrx]

this i would like to know also for downest

 

[bobski]

Exhaust Gas Recirculation system. It takes a small portion of the exhaust gasses and feeds it back to the intake to reduce emissions.
The EGR valve itself is opened and closed by a vacuum diaphram. The ECU monitors how far open the valve is with a sensor mounted on top of the diaphram housing. The diaphram is operated by engine vacuum, which is switched on and off by an ECU controlled solenoid valve mounted in a black box on the firewall.
Give me a few mins and I'll put together the troubleshooting diagram.

 

[Paul]

well since i dont have an exhaust maybe thats why

 

[bobski]

Nah... The exhaust gasses are pulled by manifold vacuum from a passage in cylinder No. 4's exhaust port. You should be able to run the engine without a header and the EGR system would still work.
Here's the diagnostic flow chart: