Hello all.

I’m writing this in hopes for some crowdsourced help on my car. Funds are tight and I’m trying to minimize diagnostic shop fees until I have the problem a bit more isolated.
He is the scope.
2010 Scion xD with 95k miles. 5 speed 1.8-liter four-cylinder

Problem: My wife was driving the car in normal conditions and it just died on her. She attempted to start it again and the car has a health crank sound when key turned over. Sounds like it is going to start but engine doesn’t fire, the starter just keeps cranking. When I turn the key all the way forward and let go the starter keeps cranking and will continue for about 20 sec then stop. When this first started, you could hear the motor sound like it was running for 10 sec however the starter continued to crank so you’d hear both a semi running motor at the same time as the starter cranking over. The engine running sound would diminish with every attempt to turn the vehicle over and now THERE IS NO SIGN of the motor turning over.

There were no symptoms leading up to this event. No odd firing, stalling, ect. The car had been running great for the past 3 years of owning it. And the only things I have done is change oil, air filter and tires. The only issue I have had is a battery that has repeated build up on the terminals. A handful of times the build up got so bad that the car would not start. Routine cleaning using baking soda and more recently a battery spray cleaner that revealed that there was some acid leaking (colored spray turns depending on what chemical it reacts to). *This issue maybe key to pushing a component over the edge. Read on to understand more.

Diagnostics: Here is a list of things I have done to try and chase this problem down. After getting the car towed back home, I started looking at the electrical system and was/is feeling it is a spark issue.

First thing I did was the ear test on the fuel pump thinking no fuel could be the issue. So I had someone put their ear to the pump (under the center of the back seat in this model) and turned the key. Heard the wind of the pump on turn then another on back turn of the key.

Second, rented an OBD2 tester and pulled following codes:

U0100 Lost Communication With ECM/PCM
C1241 - Low Battery Positive Voltage
C1201 SCION - Engine Control System


Chasing “C1241 - Low Battery Positive Voltage” I pulled the battery and cleaned the business out of it. The battery cleaning spray revealed that there indeed was an acid leak from the battery. So I cleaned until the signs were gone. At that point, I noticed that the Positive Terminal coming from the car to the post was corroded to all hell. Cleaned it and realized that the contact points were compromised so I replaced the entire piece from the fusible Link Block Assembly forward (just the part coming from the block that connects to the positive battery post).

To rule out bad battery, I took a fully charged battery from another vehicle and swapped for the Scion battery. No luck

Took a voltmeter with original battery and got 12.6 reading = so not battery issue (based on my testing)

Pulled the ignition coil of 1 cylinder thinking maybe related to a bad coil thus no spark but after a little digging, I learned that these don’t fail as a series. Rather individually therefor you could conceivably have 1 or more bad coil but it would still turn over AND there is typically symptoms associated of the coil going out which I didn’t have any.

Looking forward at “C1201 SCION - Engine Control System” *NOTE my check engine light was on previously due to needing to change oil. (On this model, that light triggers after a specific set of miles to alert that it is time). In hindsight, I should have cleared this code with the OBD2 or manually using the hold down trip mile button trick. SO in summation, I don’t know if this code is related to the issue or not.

This one got me digging a lot more “U0100 Lost Communication With ECM/PCM "A" Code”. My understand is that the ECM communicates spark which I feel that the engine is NOT getting by the sounds of it so far (best guess). For this, I went with trying to reset the ECM. I did the first method of removing the negative battery post then pressing the break down. Nothing happened after by way of turning. After a little reading I pulled the neg terminal for over an hour and after reattaching, the engine tried for about 5 sec then FINALLY TURNED over all the way to running but died 3 seconds later. Then another key turn, back to just the starter turning over and nothing else.

Dug a bit deeper and found a guy write about resetting / reflashing an ECM with a simple trick. This method was also what is done by some after putting in a new ECM. Take the 16 pin connector that you connect the OBD sensor into and pin/jump slots 4 and 13 with a paper clip. Once pinned, put the key in accessory and leave for 30 min. Did that, nothing changed.

At this stage, I’m thinking ECM is fried due to a possible connection with the battery issue mentioned earlier. The ECM can fail when there is a fluctuation in voltage from what I read. And while the ECM’s rarely go out, then can if there is a problem with a battery. And given that this battery has shown symptoms of acid leaks, larger than normal corrosion on terminals and the issue I found with a horrible looking, hanging on by a tread positive terminal connection. This is where I’m at. But from my understanding you can not test an ECM only everything else that connects to it to rule out other possible failures like O2 sensor, CAN Bus, ECT. And on the flip side, IF it was an faulty ECM wouldn’t I have gotten a code like “P0606 SCION - ECM Processor Error” that isolates it?

I am close to this being out of my wheel house in the diagnostic arena. And my goal is to reduce diagnostic time as best I can so if I do have to take it to a shop, I can take some of the leg work down.
Any feedback, troubleshooting, left field ideas that you have is greatly appreciated.

Thanks all. Much appreciated.

_____

 

U0100 is certainly concerning but I would suspect the computer last. I think you should follow normal no-start troubleshooting. Check spark (spark tester), fuel, air.

https://youtu.be/7syxAWw6Q-s

https://youtu.be/LuRI8bjjNho (No Start Diagnosis FASTTEC Method)

 

Further testing: started with spark test and passed then checked all relays for continuity/open, all were normal via multimeter. Pulled wire harness off of fuel pump and tested incoming volts. Came in at 11. Connected jumper cables to battery then ground and positive directly into fuel pump. No action. Hard leaning bad fuel pump based on this.

 

Hey Decksefxs
I have a late 2009 xD that is acting like this. Did you try spraying starting fluid into the throttle body? I did, and it starts and runs for a few seconds, then quits. This is making me lean towards fuel issue. The fuel pump comes on, sounds weak to my ears, bit it runs for a few seconds after the start attempt. It does not come on when I first turn the key to On, even after sitting for a few days. (is that normal?)

One other mystery: after a start attempt, the throttle body is humming, and continues until I shut off the key. I took off the breather bellows tube and the butterfly valve is being helt closed while it's buzzing - after the key is off, I can open the butterfly by hand. I suspect ours have the odd throttle body (late 2009 and early 2010 models) that has the angled intake pipe on top. (beck arnley part 1540209) and this seems somewhat rare and expensive. I'm going to clean the TB and see if that helps.

Please update if you find any new details!

 

@joecello mine ended up being a clogged fuel filter, fuel pump pre-filter and a bad fuel pressure regulator. Spendy bit of parts has only the dealer can get these but it got me up and running.

And yes I did try spring starting fluid into the box and same thing as you, it started up for a few seconds then died. I also experienced the same thing as you with the fuel pump. When I tested it by directly running power to it it didn't turn on. But once I pulled it out of the car and bench tested it, it worked fine. It's very easy to remove, and I would suggest bench testing the fuel pump by simply running up power and ground to it and see if it kicks over.

I would have never expected my fuel filter and fuel pressure regulator to be there root of the problem but it ended up being the case.

Hope that helps shine some light on your challenges