check engine light on '89 XT-6

[keltikrewser]

'89 XT-6 ER27 approx. 140,000 mi

 

friday on my way to work my check engine light came on, checked gauges, all was well. checked oil was about a qt low, not unusual, leaky oil pan gasket. added oil, drove home, light still came on. today on my way to work, again with the light, stopped at McD's to grab some lunch and continued on to work, no light? left work tonight, light

 

here's what i've discovered light comes on when water temp goes up, not sure if that has anything to do with it but when the thermastat opens and the temp gauge goes up thats when the light comes on. the light will not come back on if the car is still warm when it gets restarted.

 

is there any way to pull codes? tried the old on-off with the key 3 times trick, no luck.

 

also noticed the temp was going up all at once, not gradually as the car warmed up but from nothing to normal range, im assuming as the therastat was opening. i don't recall it doing this before but i never really paid that much attention either.

 

any ideas of what i might be looking for or how i could find it would be greatly appriciated.

 

thanks in advance

[4x4_Welder]

I'd take a look at the engine coolant temp sensor, it's probably bad. I've had japanese cars do some funky electrical stuff when a sensor goes out.

[hooziewhatsit]

There's a guide here as to how to pull the codes. I'm pretty sure the ECU on the XT6 is somewhere other than under the dash. I'm sure some one more knowledgeable can tell you where it is, or you could try some searches about it.

 

http://www.ultimatesubaru.org/USRM2/mick-usrm/electrical/ecucodes.html

 

 

(Edit: This no longer seems to be listed in the USRM anywhere???)

[Turbone]

The ECU is under the rear dash cover on the right side, next to the speaker.

I would also change the TS with a OEM one. Its cheap and just might help.

[idosubaru]

when the CE light is on, the ECU in the trunk will flash the code. as soon as you see the light, leave the car running and read the code off the ECU LED.

 

there's a stored memory mode you can access if you can't read the code while the light is on. it involves either connecting the green connectors, black connectors or both (they hang right by the ECU and should remain unplugged for normal driving). they are for testing, but i forget which ones to connect for read memory mode.

[Turbone]

The green connector is the Read Memory mode. The black connector is the Dealer Check mode. Use the Memory mode first to check the codes.

In order to use the Dealer Check Mode you have to go thru a complex sequence . First try the Read Mem mode and get the codes and go from there. If you still have problems, I can scan the sequence for you. The same goes for clearing the codes, but there is a simpler way to do it. Just unplug the battery overnight.

[idosubaru]

also if you have multiple codes in "read memory mode" with the green connector connected you can clear the codes to start fresh.

 

in other words if you have 5 codes, 4 might be 2 years old and one is the recent trouble maker. if that's the case i believe you connect both connectors to clear the codes. then the memory will be cleared. first time you see the CE light after this, check the read memory mode again and the one stored code that you're looking for should flash.

 

this all sounds more complicated than it is..

[keltikrewser]

got into the trunk and hooked up the green conectors and turned the key on. all i got was 1 long pulse every couple of seconds, even length pulse and longer even length pauses. that would be a code 10 right? i read the tread in the USRM and obviously the are not codes that end in zero, what does this mean? also while i was checking the codes the fuel pump kept cycling, it would prime every few seconds, i could also hear some noise coming from what apears to be a check valve on the back of the passenger side fuel rail, im assuming that this was just releasing the fuel pressure as the pump kept priming not quite sure what is going on.

 

i have had some spuratic drivability problems lately, which seem to be fuel related, the car will seem to randomly choke itself and stumble until i let off the gas slightly, it then sounds like it pops in the exhaust manifold and then i can continue accelerating or maintaining speed. this has been happening on and off for a couple of months, with no real consistancy. i replaced the cap,rotor,wires, and plugs but it seemed to make little if any difference.

 

thanks again

[Turbone]

Sounds like you need to clear the old codes first like Gary said. Its normal for the fuel pump to cycle when the green conn is hooked up also.

If you havent changed the fuel filter, located in the engine compartment, drivers side behind the strut tower.

[idosubaru]

fuel pump cycles on as part of the test mode, that's fine and good. it's working as it should.

 

if you get no codes in the test mode, that's good.

 

you need to look at the codes the ECu flashes when the CEL comes on or do the read memory thing i already mentioned.

 

this is very unlikely to be fuel related, trust me. it is most likely coolant temperature sensor related. notice i said "related", not the coolant temp sensor itself. but i'll let you snag the codes before getting ahead of myself. no, let's get ahead...by the thermostat housing (the second radiator cap that's not on the radiator), there's a 2 wire connector. this is the CTS coolant temp sensor. is the wiring harness corroded, cracked, brittle, dirty? pull it off and have a look inside. see the green, nasty, corrossion. that's your problem.....

 

let us know what code you snag.

[keltikrewser]

checked the codes when i got home tonight with the car still running, you guessed it, BLACKJACK! 21, cts. didn't have a chance to look at the wiring or inside the t-housing, i'll check that tomarrow and let you guys know. did call my local advanced auto parts, $18 instock for a new cts.

 

pull it off and have a look inside. see the green, nasty, corrossion. that's your problem.....

 

im assuming you are talking about the t-housing, what is going to be my best plan of attack? just flush the cooling system or something more aggressive?

 

thanks for all the help so far

ryan

[idosubaru]

good, this is easy to fix and i'm going to save you $18...though it might require some work on your part.

don't waste your $18 on a new sensor. it won't fix the problem. to be more accurate, it will fix the problem but only temporarily. the sensors never fail, the contacts get dirty and corroded. a new sensor has new contacts so it will "fix" the problem but only for a short period of time.

 

here's the permanent fix i do to all of mine:

http://www.xt6.net/forum/viewtopic.php?t=1767&highlight=temperature

[keltikrewser]

looked at the sube last night, connector looks great, both halves were still shinny, cut into the wire and that looked good too.

 

then i noticed that i was dripping some coolant onto the ground. i found this odd because i have never seen my car leak antifreeze, could not find where it was coming fom it was collecting onto the splash gaurd under the battery tray and dripping off of that. i know my rad. is on its last leg, the bottom 1/3 of it has no fins left, been that way since i bought it with no problems so far.

 

so i checked the coolant which was low, it took 1 1/2 gal. to fill it up. took the car for a drive to see if the light went away. light didn't come on, but like i said before it wont come on if the engine is warm so i figured this was the problem. checked this morning for any coolant on the ground and found nothing. drove to work, no light, could that have been my problem, low coolant? if so let me know and i'll go hide under one of the rocks in my back yard

 

where can you get a new rad. for an XT other than a Sube dealer? or would i be better off trying to have mine repaired?

 

thanks again for all you help

ryan

[idosubaru]

where can you get a new rad. for an XT

you mean XT6...completely different animal between XT and XT6. the XT radiators can be had for under a $100 on the internet or at stores for just over $100.

 

the XT6 radiator is Subaru OEM only. don't bother trying to find one, no aftermarket radiator manufacturer ever made one for the XT6. if you try to look you will find place that say they can get them, but they are wrong, they will always be XT radiators...eventhough their computers say XT6.

 

your options are Subaru New OEM - $400 - $600 at the dealer. you can get them from some on-line Subaru dealers for around $300.

 

used ones can be found for $50 - $100 but that's not a good solution as they are typically 20 years old almost. overheating is bad, don't cut corners like this.

 

you can attempt to retrofit the much cheaper XT radiator. get an XT radiator hose to help install. i haven't done it but know others that have. Cut about 2 inches of XT radiator hose (it is smaller than the XT6) and install that on the radiator outlet pipe. then install the XT6 hose over top. do this for the inlet pipe too.

 

then you'll have to play with fitment i believe as well, the bottom brackets won't line up with the holes in the XT6 radiator support, but with some creativity it can be made to work. same goes with the fans, i don't think the mounting holes of the XT6 fans will line up, but that can be remedied fairly easily as well.

[Turbone]

Like Gary said, OEM only. But, I would try and find a shop that does quality work and see if it can be rebuilt. If its substantially cheaper than new, it would be the better choice. I would think if its within $100, I would just buy a new rad. I got lucky a while back and found a newer rad in a XT6 in the local PAP and have had no probs yet.