Car died on side of road and wouldn't start. Looking for the problem.

Asked by Jan 17, 2017 at 04:12 PM about the 2008 Subaru Legacy 2.5 i

Question type: Maintenance & Repair

Car died on road.  plenty of battery power but won't crank.  Towed car to a
repair shop where they checked for shorts, bad grounds, etc...found
nothing...would not read codes from ECM either....it ended up starting and
running for 50 miles then did same thing.  sitting in my garage now...gave
codes briefly...one for cat efficiency and another that said ECM 672

7 Answers

74,095

Maybe it is time for a new ECM. Has anything happened to the car recently or any repairs been made in recent days? Not sure what ECM 672 means.

The used car dealer's mechanic says to try the upstream and downstream o2 sensors.....I tend to think it may be the ECM...Supposedly there was no history of this ever happening before this week according to the dealer. But we have only owned the car for a couple weeks and the dealer mechanic is the last mechanic to do any repairs to the vehicle

5,280

The CEL cat eff code was probably a PO420...if so ignore it for now. I too doubt that your ECM is screwed...UNLESS you bought a previously-flooded car, as the ECM sits under the passenger front rug (under glove box). You can pull up the rug from the front and you'll see a plastic shield, under which is the ECM andits harnesses. If they were under water I'd return the car under lemon law as a possible "salvage" status vehicle. State laws vary here.... O2 sensors have their own codes, so that's unlikely. Motor will not crank? Wrench check starter/solenoid operation? If ok car should crank. (If crank but no start check simple cam/crank front sensors as the ECM is "blind" to their function and won't throw a CEL.) I've to date not had to change a solenoid nor starter in any 2006- 2009 similar setup. The good news is that it ran ok for 50 miles, so again I'd look to the starter/solenoid operation, as "no crank" is rare if battery is strong. Need more info....

1 of 1 people found this helpful.
5,280

Just reread that car "died on road". While running?...or after you stopping it and simply trying to restart? The former would suggest it's NOT a starter/solenoid issue, and maybe something goofy like a fuel pump; the latter that it IS starter/solenoid related.

It is my son's car. it just died while driving..and there was quite a bit of moisture found underneath the passenger floormat and I did see that that is the location of the ECM harnesses...ANd since the car was used I didn't think it fell under the lemon laws...

5,280

If it's been in a flood zone it MAY have a salvage title. Did you check the received Title carefully. Again, different States offer consumers varying rights re used vehicle purchase. Under Mass law, for example, there would be both a general consumer protection as well a used car law protection. If you can't return this chariot that swam with the fishes at least remove and air-dry the ECM for several days and retry. Depending upon model some are easily uncased so that you can inspect the inner master pc board for wetness and/or residue...as well to speed drying. If no go, chase a pre-owned ECM, being carful to match, including 2-3 character code on outer case if possible, or you may lose an accessory function. Oh...just remembered: you must have your replacement ECM "coded" to your electronic ignition key or it won't start. Most mobile key services (as well Subaru dealer) will match your "new" ECM to existing keys quickly. Subies usually dry out successfully, but of course the ECM may need particular care. Check the top-of- transmission master harness connectors too. Even though they sit higher up, if the flood was severe they'll become oxidized and intermittent.

1 of 1 people found this helpful.

Thanks! I will definitely try drying the ECM and pursue a return / refund of the vehicle...

Your Answer

Legacy

Looking for a Used Legacy in your area?

CarGurus has 13,207 nationwide Legacy listings starting at $1,399.

ZIP:

Subaru Legacy Experts

  • #1
    Anthony_60
    Reputation
    1,270
  • #2
    Nick Eidemiller
    Reputation
    720
  • #3
    dandyoun
    Reputation
    700
View All

Related Models For Sale

Used Subaru Impreza
202 Great Deals out of 18,295 listings starting at $1,500
Used Subaru Outback
386 Great Deals out of 36,766 listings starting at $1,395
Used Subaru Forester
379 Great Deals out of 33,405 listings starting at $995
Used Honda Accord
1,002 Great Deals out of 62,552 listings starting at $999
Used Subaru Impreza WRX
61 Great Deals out of 1,293 listings starting at $3,365
Used Toyota Camry
1,072 Great Deals out of 72,796 listings starting at $1,000
Used Honda Civic
830 Great Deals out of 78,168 listings starting at $900
Used Subaru Impreza WRX STi
38 Great Deals out of 657 listings starting at $9,998
Used Ford Fusion
1,103 Great Deals out of 76,417 listings starting at $1,299
Used Audi A4
307 Great Deals out of 10,684 listings starting at $1,500
Used Nissan Altima
1,124 Great Deals out of 74,485 listings starting at $999
Used BMW 3 Series
1,047 Great Deals out of 31,468 listings starting at $1,000
Used Mazda MAZDA6
190 Great Deals out of 13,413 listings starting at $1,395

Used Cars For Sale

2018 Subaru Legacy For Sale
3,413 listings starting at $20,405
2017 Subaru Legacy For Sale
27 Great Deals out of 4,310 listings starting at $14,478
2016 Subaru Legacy For Sale
31 Great Deals out of 682 listings starting at $12,888
2015 Subaru Legacy For Sale
38 Great Deals out of 1,236 listings starting at $9,990
2014 Subaru Legacy For Sale
32 Great Deals out of 887 listings starting at $9,290

Content submitted by Users is not endorsed by CarGurus, does not express the opinions of CarGurus, and should not be considered reviewed, screened, or approved by CarGurus. Please refer to CarGurus Terms of Use.