91 HF
b16a obd0 with chipped pr3 and apexi vtec control.

Had the swap originally done at a local shop about 2 years ago. Drove fine and never had any issues with the car.

Well after realizing that my reverse lights dont come on when i go into reverse i found out that the shop didnt connect the reverse wires and so i connected them and thats when the problem started. Well once the car is started there is no check engine light and idles fine. But once i put the car into reverse a CEL pops up and idle drops and gets a little choppy when i drive it in reverse only. Pulled the code and turns out to be #6 coolant temp sensor?

Also obd0 requires 2 single wired o2 sensors but im only running one. Car ran perfect for the past 2 years but i want to get my reverse lights one without running into this problem. should i replace the coolant temp sensor?

 

yea, replace the sensor. and make sure your backup light wires arent damaged or ripped and make sure they are not shorting out on the trans...

!!!! are you sure your reverse lights from ano obd0 motor? and are you sure the wiring is right?

 

err.. are you sure that you don't have your coolant temp sensor and reverse indicator plugs swapped? Something with your wiring sounds jacked dood

 

Remove pin B9 on the ECU... ALL B-Series HFs have this issue, very well known etc.

 

I have the same problem car runs really good and strong with no checkin engine lights or anything but when you put it in reverse with it hooked up the damn thing spits sputters and goes crazy throws a check engine light
you say remove pin b9?? is that on the ecu like break the pin off? cause your diagram doesnt show a wire in that pin or am i wrong and only the HF cars have this wire? id like to kno also because mine is unhooked i have a 90 hf with jdm b16 obdo ecu will this be fixed if you go to obd1 because i plan on going to a p28

 

bump does anyone else kno if this is true??????

 

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by 1990hondacrx &raquo;</TD></TR><TR><TD CLASS="quote">bump does anyone else kno if this is true??????</TD></TR></TABLE>it is true - the wire is only on the HF - green with black stripe - just cut the wire

 

i don't know what that wire b9 went to but the guys are correct i unpinned the wire and the reverse lights worked fine and it back up without miss firing and throwing a code

 

nice

ill depin it asap

 

thank you

 

the reverse lights on the crx should be just wired to a pushbutton switch screwed into the tranny. someone got their wires swapped cuz the coolant temp switch is right in the same place almost. its probably monitoring the resistance for the temp sig, then u throw it in reverse and they get tied together and the ecu flips out.