Jump to content
Ultimate Subaru Message Board

Help please! 96 outback stall, no start, no spark, no injector pulse


Recommended Posts

As I re-read these posts, there seems to be conflicting information, so i can understand if anyone's confused.  I surely am.

 

What I know for sure:

 

1) With ignition on, there is 12V to yellow wire at fuel injector #1, but no ground on brown wire, so no noid light (and no pulse when cranking)

 

2) The FSM says to test the ECM Connector detached from the ECM and look for 12V between 1 (+) and 19 (-).  With the cable detached, I am seeing no (+) signal on terminal 1, so there is no 12V between 1 and 19.  It does appear that 19 is a good ground.

 

3) When I reconnect the ECM cable, I do see 12V on terminal 1 if I probe from the back of the plug.

 

I really want  to understand the power sequence and how the main relay plays in.  I don't understand why there is no power to ECM plug terminal 1 when disconnected as that is directly contrary to what the FSM suggests should be happening.  Then I really don't get how there is magically power to it once the ECU is plugged in.  Something somewhere is stuck open or closed improperly unless the FSM tests are wrong.

Link to comment
Share on other sites

to me, that indicates there is some other reason for the no-start than a 'dead' ECU. The ECU cycles the pump and is responsible for 'timing' the cycle.

 

OF COURSE different input-outputs can still be compromised, but you'd want to be certain there is no other possibility before swapping-out the ECU. The ECU is not satisfied for some reason that the car should start. Security or confused cam/crank sensors, 'neutral' safety/brake switch,etc. or ????

 

does this car have an aftermarket remote start? they are notorious for these type problems.

Link to comment
Share on other sites

you haven't connected any green or black connectors you discovered under the dash have you? they are only for diagnostic purposes and can confuse folks troubleshooting problems.

 

also, any smell of fuel at the exhaust when cranking? maybe the plugs are flooded and wet. cranking with the pedal on the floor will signal 'clear flood' mode to the ECU.

Edited by 1 Lucky Texan
Link to comment
Share on other sites

So here's where I am at . . .

 

Need some help.

Car died. Now, the starter will crank, but getting no fuel injector pulse and no spark.

Tested or done so far:
1) Replaced Crank Sensor
2) Replaced Cam Sensor
3) Pulled Timing Covers, all is spot on
4) Verified 12V to Ignitor and Coil Pack, but no pulse
5) Verified 12V to yellow wire on injector 1, but no ground in brown wire, so noid will not light at all. Whether ON or IGN or OFF
6) Bench tested main relay per FSM procedure and it energizes and throws 12V to all 5 ports
7) Unplugged ECM connector to do tests as per FSM.
8) First test is for 12V between 1 and 19. No + on terminal 1, 19 has ground =FAIL tango_face_sad.png
9) Second test is for 12V between 2 and 19. No + on terminal 2, 19 has ground =FAIL tango_face_sad.png
10) Third test is for 12V between 39 and 19. + on terminal 39, 19 has ground =PASS
11) Fourth test is all ECM grounds 17, 1, 19, 20, 42, 46, 69, 94, 95, all show continuity to known body ground =PASS

So, I am leaning back to main relay as I believe that is the part that throws power to terminals 1 and 2 on ECM, but the guidance is confusing in FSM. 

I don't really understand how power gets from battery to terminals 1 and 2 in ECU connector (B84). Is it solely from the main relay? If so, what triggers the main relay to throw that signal? 

In terms of downstream from the main relay, I can see the following:
Main relay (MR) terminal 1, I see proper ground (PASS)
MR terminal 2 appears to be tied to ECM 63 and I am not seeing signal come through (FAIL)
MR terminal 3 appears to connect to ECM terminals 1 and 2 and I am not seeing the signal come through (FAIL)
MR terminal 4 appears to go to IAC solenoid and purge control solenoid, haven't tested. (UNKNOWN)
MR terminals 5 and 6 seems to come from SBF2 and I see 12V + constant. (PASS)

So, I need help understanding the sequencing in the main relay as to what triggers what because clearly I am not seeing power come back from MR terminal 3 to power ECU 1 and 2 when the harness is unplugged.

Also, should the MR click to engage every time the the key is turned from off to on? It doesn't seem to do so, so that makes me wonder if there is an issue inside the MR.

Am I going down the right track?

Any other ideas???

Link to comment
Share on other sites

I remember reading a post on here a while ago where someone had a crazy problem like yours and had no indication that his main relay was bad until he tried a different one. At least you have pinpointed that your ecu isn't receiving switched power, it seems like you have tried everything but yes, the main relay should click on every time you turn the key to on. Have you tried to power probe the relay to see if it clicks every time? Then maybe have a friend test the ecu while you hold the relay open. I know it passed the bench test already. Perhaps it is something as simple as your ignition cylinder not acting right, but the damn thing should at least give you some spark if your ecu supplies voltage to the coil.

It's rare but some have had problems with the main relay.

Edited by sparkyboy
Link to comment
Share on other sites

When I changed the crank sensor, the cable was still intact, but my guess it was solely the insulation that was together because BOTH contacts broke as I rechecked it. So props to Subaru's OBDII code as the only one that had lit was crank sensor and it was correct. It had lost crank sensor communication.

I had to repin using the existing Subaru connector as I don't see any aftermarkets, so I guess I have a little something on my salvage yard wish list for Santa.

Once repinned, it fired IMMEDIATELY!!!

So, the chase to 300,000 miles continues!

THANKS TO EVERYONE WHO HELPED!

Link to comment
Share on other sites

Join the conversation

You can post now and register later. If you have an account, sign in now to post with your account.

Guest
Reply to this topic...

×   Pasted as rich text.   Paste as plain text instead

  Only 75 emoji are allowed.

×   Your link has been automatically embedded.   Display as a link instead

×   Your previous content has been restored.   Clear editor

×   You cannot paste images directly. Upload or insert images from URL.

 Share

×
×
  • Create New...