legacycentral bbs

Well, when I'm driving on the highway and just cruising at constant speed for a while the strangest thing hapens. The power light comes on for a couple of seconds then goes off. It does this a couple of times then stops. Its not flashing a code or anything it just happens randomly when crusing at a constant speed. Any thoughts?

My 92 Sport Sedan was having the same symptoms today while cruising at 65 MPH @ 2500 RPM. The power would kick in for a couple of seconds, the car would lunge slightly, and then it would kick off. It also appeared to be random.

TPS not giving steady signal maybe? If it falls then jumps, that can activate the power light causing it to downshift. You are not making any abrupt throttle movements when it happened? I guess with the car off keep flooring the pedal quick, see if that cleans up the contacts on the TPS.

Well, I did as you suggested, Ericem, but I'm not sure if it helped or not. I haven't been able to take it on the freeway, yet, but I will when I'm done with work. Where is the TPS located? I've had my issues with that damn thing on my 89 VW Vanagon. Can the TPS be adjusted? Where are the contacts and are they accessible to clean, maybe with an emery cloth or that electronic cleaning spray?

Thanks!

It is right here, its hooked up to your throttle body.



See the plug facing to the camera with the red, white, orange wire? That plugs into the TPS. I am pretty sure you can take it apart. I believe the stock adjustment is marked in white. There is a manual how to set it up. I reset mine using a meter to see when the circuit was open or close. If it is not adjust properly it will affect your idle. Let me find it.

Here it is.

http://www.main.experiencetherave.com/s ... sting3.jpg

I think it is related to the tps yes. I also was getting that same day a cel at stop lights at idle. It was for code 42 I think which is idle switch. I checked the tps and it lookes like someone had a "T-Tap" on the wires the jacket is gone and there are bare wires showing. going to fix it this weekend. also, checked the tranny for codes and had nothing.

Sorry for not responding to your post(s) earlier, I didn't check the "Notify me when a reply is posted."

I tried the flooring option with the car off (as it seemed to be the easiest to do at the time). It seems to correct the power light issue temporarily. I drove to my parents cabin this weekend, and it would start to occur after about 30-45 minutes of driving. I could pull over, do the pedal pump dance, start up and be fairly trouble free for 30-45 min before it would start acting up again. On the way up to the cabin (the last 1.5-2 hours in snow) I got to the town and my power light was intermittently coming on and off and the CEL turned on. I told the car, "Come on Subie, don't do this to me," and the CEL went off. The whole drive home the CEL didn't come on, but the power light symptoms returned.

I also have noticed when its in this state, it will shudder or stumble slightly when I back off the accelerator. Could this be related to the TPS not being adjusted correctly?

Like I said, I did not realize the additional posts, and I apologize. I will look into the adjustment procedure and see if that clears up my problem. I also did the 4WD lock modification (flip the switch to lock the rear differential) could this have affected it? Seems I was getting the Power Light issue with the switch on and off.

Thanks a million!

-Brent

Sorry, one other thing, my idle seems to be in the 750 rpm range, is that low?

Nope normal.

Actually, I looked at it earlier today, and when warm, it looked like it was below 500 RPM, maybe 250?!? That can't be right.

Okay, maybe I'm reading the ticks wrong. It appears to be hovering around 500rpm, maybe... There seems to be a tick just off zero, is that supposed to be 500? Then the smaller tick between that and 1k is 750?

Thanks!

You're reading the tach incorrectly. The tick that looks like 500 is 750.

Try pulling the codes from the ECU and TCU

info is on my site

www.surrealmirage.com/subaru/engine.html

www.surrealmirage.com/subaru/trans.html

The AWD switch you put in could very well be giving you your problems.

Legacy777 wrote: The AWD switch you put in could very well be giving you your problems.

If I start the car with the switch off (locked 4wd mode, power cut to the Duty-C Solenoid), this will throw a code, the power light flashes around 16 times (I haven't counted). Which means the obd has determined the Duty-C to not be functioning or present.

If I turn the switch on (normal AWD mode, with power being supplied to the Duty-C Solenoid) and start the car, the power light does not flash, hence it won't be throwing a code for the Duty-C solenoid.

This morning I took the Subie to ABC Transmission in Tacoma, WA and had the pan dropped & cleaned, and a transmission flush. Drove it on the freeway for about 5-10 minutes and did not notice the Power Light issue. I don't think a tranny flush would correct the Power Light issue, and my drive very well could have been too short.

I have yet to pull the codes from the ECU and the TCU. I'm assuming I will find the Duty-C error code present, but I will let you know what else I find.

Thanks for the great resources everyone!

The 16 flashes is a default flashing code. The initial flashing does not indicate a specific code. You will more then likely find the duty c code, however I am more curious about what else you find in the TCU and ECU.

Legacy777 wrote:...however I am more curious about what else you find in the TCU and ECU.

Me Too!

Ok, I've been able to retrieve the stored codes in the TCU. I haven't attempted the ECU, yet.

The TCU is throwing three codes:

24 - Duty Solenoid C (figured that one)
32 - Vehicle Speed Sensor 1
33 - Vehicle Speed Sensor 2

So, I know why I got the Duty Solenoid C code, now I'm going to see if I can figure out the Speed Sensor(s) problems. These are stored codes, there were no present codes being thrown. Hopefully, I will be able to get to the ECU either tonight or tomorrow morning.

Thanks!

What you need to do is check the ECU, and then clear the ECU & TCU's memory, and then recheck for codes once the light goes on.

More times then not there are erronous codes that pop up with an actual problem. So it's hard to say whether the speed sensor codes popped up because the duty c solenoid code. It's very possible. Which is I why I said your 4WD lock switch could be causing your problems.

I understand. I will check the ECU codes once the rain holds up or I can get into a garage. Just don't want to have to crawl on the wet pavement if I don't have to.

I took it on a slightly longer freeway drive today in the pouring rain without any problems, but it is not nearly as long as the drive I took this past weekend where the issue manifested itself.

A tranny flush may have helped my problem, but I'm not convinced, yet...

Ok, after much searching, I was able to find the black connectors and I got one error code:

42 - Idle Switch

Makes sense, MagicMike you nailed it. So I'm assuming if I do the TPS adjustment, I should be golden, right? Hopefully, I'll be able to understand the lingo... I'll let you know what happens.

Thanks for all the help.

Stick my nose in here...I had the random Power light flash, too. It was due to low fluid level after I did a fluid replacement. Put in enough to bring it up to Full and no more issues.

Good luck.

wtdash wrote:It was due to low fluid level after I did a fluid replacement.

Which fluid? I don't think windshield washer fluid would cause problems, lol. My situation was more than the light flickering, I could feel the car entering into Power mode, too. It has to be either the TPS needing adjustment, or the TPS needing replacing (Hope not, not sure what a new one would cost).

Thanks for your "nose-sticking" though.