code 6 on a 91 ls swapped crx

We may earn a small commission from affiliate links and paid advertisements. Terms

D

DeathInACRX

New Member
hey guys ive searched here and i cant quite find a diffiinitive answer to a problem imdealing with. i usuly do, thus the lack of posts by me. thanks!:D any way the issue i have is a code 6 engine coolant sensor. the c.e.l is on because it is not hooked up. the engine i had just put in had the connector on it but i had no place to put it in my harness. the reference books that i have only address the one on the head and not the one on the termostat, (this is the one that is not hooked up.) my question to you all is can i hook these two wires some where in the ecu to make the c.e.l go away or is it something totaly differant than that. pictures would work wonders but any help will work thanks
 
Your original engine should have had 2 sensors on the back of the block (by the oil filter). The larger one with 2 wires is the temp sensor/fan switch. Your OBD0 LS has the switch in the t-stat housing instead.
Extend the 2 wires on your original harness and add a plug to connect to the new switch. You should have a plug leftover from the swap.

Now, that solves the question of how to hook that up, BUT...that switch being unplugged shouldn't cause a code/CEL unless it ran long enough to actually overheat. It's a normally open switch that only closes to tell the fan to run, so the ECU sees it unplugged the same as the engine being cold. In fact, you can twist those two wires together and the fan will run all the time. If the code persists recheck the head sensor and wiring.
 
what he said ^ lol. it will not throw a code if the coolant fan switch is not hooked up. nor will it throw a code if the ect sensor for the gauge cluster is unplugged. the only thing that would throw a code is the 2 prong connector that gives ect readings to the ecu that is located on the side of the head.
 
thanks for the quick replys. i tried what you suggested and the code still is there. i want to post pic of what ive done, but i need to learn how. peace
 
im back after exhausting many hours and dollars to still have the damn light stay on.:confused:
i thought the easy fix would be to just buy a new sensor. wrong 25$ down the drain. so having no other choice i took out the engine harness out of the car to see if there was a break in any of the connections and there was. the wire sheething had broken due to it being old and crusty and bent but the wires were not severed. so i soldered on fresh wire and shrink wrapped it. thinking i was done i decided to de-loom the whole harness just to make shure the entire connection was complete. it was but the harness was hacked up buy the previous owner. im wondering if he got something wrong because the wires to the ecu are hacked up and not being a great wire harness modifier could that be where the check engine light is comming from? registration is comming up soon and the smog guy wont pass with a check engine light.
 
here are some pics of the hack on the wires to the ecu for all those who can decyper it buy just looking at it. its a dx CRX and the ecu is pr4
CIMG2437.jpg

CIMG2438.jpg

CIMG2435.jpg
 
yikes! what possesses people to muff up harnesses like that. its definitely a possibility that the hacked up wires could be the cause of your cel.
 
code 6 is from the ECU temp sensor which is on the end of the head - has 2 wire connector with red with white stripe and green with white stripe wires - the single wire senor on the end of the head is the temp gauge sending unit - the sensor on the back of the block on the OBD0 engine is the cooling fan switch - on the OBD1 engine, the cooling fan switch is on the thermostat housing
 
im retarded, i did not realilize that "tw sensor" stood for ect sensor. duh
and i did not even look to the sticky ecu pin out thread. sorry thanks for your help none the less and i hope what ever i do next will fix my problem. peace
 
so i finaly got it fixed. turns out one of the ect wires was put in the wrong place in the plug leading to the ecu. also i was able to wire up the coolant fan switch. i ran the car for 15 mins no codes and the fan came on!
 
You must log in or register to reply here.
Back
Top