Power light doesn't come on when ignition is turned on

[pjager]

I have the 94 legacy fwd wagon with automatic transmission,. I turn on the ignition and no power lite, I have to wait 1-10 minutes for it to turn on. If I start the car before that the transmission slips, if I wait and it turns and start car then transmission does not slip.

I get no flashing lights , just have to wait for it to turn on before starting. I dip have engine light on with code 32 and 35, car runs good though, will check if purge valve wiring is bad or valve is bad.

The other shows o2 sensor inop., will check wiring, but if I remember right we have 2, so which one would be bad?

I can clear all codes and wait for them to come back, have disconnected battery, wait ed and reconnect, engine will come back. Or do I need to do it by connecting the 2 sets of cables ( black and t- green to clear?

Any help is greatly appreciated, peter

[Legacy777]

Hi Peter,

Regarding the power light not coming on, I would recommend checking the power supply to the TCU to make sure it's getting power once the ignition switch is turned on. Have you tried performing the tests to check for stored or active codes in the TCU?

www.surrealmirage.com/subaru/trans.html

These cars only have one 02 sensor, so yeah check the wiring to see if it's ok or not. If it is, you may want to replace the O2 sensor.

You should be able to clear the codes either by using the battery method or both the black & green connectors & by following the appropriate procedure.

[Legacy777]

Hi, the problem I am having is that I have to wait for the power light to come on before starting. I sometimes have to wait 1-10 minutes, and the codes I said I have, we'll sometimes the engine light doesn't show any problems.

I am getting power to tcu, the manual light can be turned off and there is a difference in the shift pattern and it's smooth. Whether there is a problem with the tcu inside of it, that a resistor or something burned up. I just hate waiting for the light before startup, and if I start it before the light finally comes on my tranny slips, if it comes on and I start the car it doesn't slip.

I have been looking at the wiring diagram and noticed that the tcu works off of the throttle sensor to, any advise is greatly appreciated.

As for testing system because of the light issue not coming on as you turn on key makes it hard to retrieve any codes. I don't think I have any codes though, I get no flashes at anytime when starting car.

Peter,

The power light should illuminate immediately once the ignition is turned on. If that is not happening, and you've confirmed that the TCU is getting power immediately when the ignition switch is turned to the "ON" position I would then suggest getting the codes. The procedure should still work, even if you have to wait for the light to come on. If none of that works, I'd maybe suggest trying to find a used TCU from a local junkyard or from a member on here that you can try.

[pjager]

Hi Josh, well finally got the transmission to do the codes, no new. Ones and no old ones, just had the continuous 1/4 second flashes on both checks.

But I still have the power light issue, still get the same 2 engine codes, but now sometimes the engine light turns off after car is started and sometimes it stays on.

And last night coming home going uphill the car felt like it was losing power and started to run horrible, lots of vibration from engine , pulled over put in neutral gave it some gas and it clear up and let off gas and ran like crap.
2 minutes later it cleared up, no additional codes just 32 & 35
Checked wiring, cleaned with cleaner for wiring, nothing.

Thanks for help

[Legacy777]

Hi Peter,

I really don't think either of those codes would cause the problems you are having, but generally it's a good idea to investigate and repair/replace any of the components indicating issues so the ECU does not get a code.

If you didn't get any codes from the TCU, I still would suggest checking the power supply to the TCU to ensure it's coming on right away when the key is in the ON position. Have you been able to do that?