Severed TSX

I have been reading through forums for the past week and a half so I apologize if this becomes long winded however I have tried a lot so here it is...

To start off the car will not turn on. I recently purchased my 04 TSX and it had to be jumped from sitting on the lot. I ran it for a few weeks and put over 1000 miles on it. It seemed to be starting slower and slower though when I turned the car on each time. Eventually it just wouldn't start at all. Typically I'd have the battery tested but not knowing how old it was I just bought a new Optima yellow top. The car started for a few days fine after that and then I ran into the same issue. No click when turning the key but everything inside the car had perfect power to come alive. No dimming of lights, radio worked, vents blew air all like they should.

At this point I figured it was something else in the charging system. Since I was going to have to remove the intake manifold to get easy access to the starter I figured I would just do both the starter and alternator at the same time. I've never had either go bad on a Honda/Acura before but they were not outrageously priced so I bought both assuming I would cover all of my bases. They were crusty from PA winters but the contacts on both looked good. I removed the old and installed they new hoping to keep the car forever and not have to worry about those parts again. The car started up fine first try and I ran it for a day and a half with no further issues.

I start the car to go to work and it comes on fine. I get out to get my work keys from another car and I hear the engine and exhaust "hiccup" but it then keeps running fine. I get in to see the check engine light on and later find it kicked a P0685-ECM/PCM power Relay Control Circuit/Open. I drive to work and the car runs fine. I leave work and the car won't start. Here's what I get... Relays clicking from both the drivers kick panel and behind the glove box, dash lights flashing rapidly, starter can be heard turning over but engine will not "turn on". When the key is on position 2 it continues to click and flash all dash lights. I do not have an aftermarket alarm installed.

Here's what I know/ have checked
-Fuel pump is feeding to rail and has pressure
-same results when trying both chipped ignition keys
-all engine grounds have been removed and cleaned
-cables to alternator, battery, starter all secure and clean
-replaced negative battery cable for good measure
-checked for recall that some 04 TSX have for ECU getting water damaged by clogged ac drain as well as ignition starter switch know issue and not available for my VIN
-trying to jump the battery changes nothing
-replaced PGM-FI main relay 2 in driver kick panel
-replaced Multi Block (100A/70A) Fuse A in engine bay fuse box (looked fine but getting desperate)
-strangely removing one of the 2 relays behind the glove box stops the clicking but car still won't start with it out, swapping them around changes nothing either - still clicking and flashing lights
-everything that was removed when I removed the intake tubing, manifold, and fuel rail/injectors has been gone over twice. All looks fine and is hooked up as it should be.
(I may have forgotten something because it's been a long week)

What I haven't tried/ looked at yet
-I have an ignition starter switch on order because I hear those go bad often on these models
-(my worst fear) ECU is damaged or issue with factory security system. I have not removed the main computer yet to investigate but thinking back to the OBD II code that was originally thrown I have my concerns.

I have been working on Honda Civics for the past 6 years, have done engine swaps and basic maintenance as well as after market bolt on parts with no problems. The car has been towed to my local general mechanic, not an Acura dealership, and he has no clue what's going on. He has confirmed however that I'm not incompetent because he has done all of the same troubleshooting I had before having the thing towed. Obviously I don't want to pay someone if I can research and figure it out on my own. A friend of a friend is looking at it in a few days who works at a Ford dealership and strictly works on the electronic end of things in a their service dept. I figure he can at least test some things or perhaps see something I have missed but I realize he will probably be limited due to knowing Ford and not Honda/Acura. PHEW!! Any additional assistance would be greatly appreciated because the next step is to either tow it to an Acura dealer or pay someone to crash into it and collect the insurance money. Thanks in advance!!

TexasHonda

Car won't start w/ new starter and battery. Symptoms suggest low battery voltage.

Check battery voltage to be sure something is not discharging the battery while parked; parasitic current draw from some source. Check Key Off battery amp draw. Battery voltage should be >= 12.2V.

Check voltage drop across battery cables (pos and neg) when starter is On (key to start). Voltage drop should be < 0.5V. If more cable has a fault.

When no-start is present check blk/wht small wire to starter solenoid for start signal. No signal means faulty ignition switch or starter cut relay.

good luck

monitor51

I'm no expert, but you've done what I would have. To me it sounds like the car thinks it has been stolen and the factory low jack has kicked in. Where to do from here I wish I knew. Just a thought.

curls

I'm not sure the factory alarm is causing any issue - my hunch (and it's just a hunch) is that the car will not respond AT ALL if the wrong key is used / the alarm is tripped. I doubt highly that it would flash and try to start but have a fuel cut-off -- I'm thinking the starter wouldn't even engage to begin with.


Check out what TexasHonda has said - he's an Acura mech, as far as I know.
Also, is your battery charged? Not voltage-wise, but charged via a batter charger so that you can 100% rule out the battery, and maybe focus on a parasitic draw causing the problem of low CCA from the battery -- I've seen the flickering lights/relays clicking before, and in all Hondas I've seen it, it's been a lot battery symptom 100% of the time.


The P0685 code could be a hint as to where/if there's a parasitic draw. Unfortunately, my thought is that if it's a parasitic draw that throws a code, it's IN the ECU...

Severed TSX

Thanks to those who have replied. I found a good deal on a used ECU that comes with matching keys, imobilizer, ignition, and all matching door locks for my car. I'll have that hooked up in the next few days to see if that works. I skipped on having the electronic tech look at it because after mulling this over for the past few weeks it is most likely the ECU or some security bug. It's a money gamble either way I guess hah. I'll update after that's tried to see if we have a resolution. For good measure I'll fully charge the battery also since I'm sure the mechanic has been trying to start the car non stop since I dropped it off while he was checking things out.

curls

Good idea. Plus if you find the ECU doesn't help - you can sell it!

Severed TSX

I figured I'd update this thread as a few things have changed since my last one. I got a call from the mechanic the morning after I dropped off the new(ish) ECU and ignition parts. My car was running great... but he never installed the parts! He removed the cover from the ignition housing on the steering wheel and "wiggled some wires" as he said and also did the same to the ECU. The car started right up. Coincidence? Who knows? He did then remove all of the wire harness plugs and reinstall them for good measure. After all of the troubleshooting it did seem like either a computer or security issue but perhaps just a loose connection in the cabin. In any case it works now. Since it feels like some kind of ghost issue at this point I'm paranoid that it will just randomly happen again in the future since there was no real fix but I know that feeling will dissipate over time. My mechanic did drive the car around for a few days so if it broke down again it was just around town. I'm hanging onto the parts I've ordered for a month or so just to play it safe.

monitor51

Wow, jiggle the handle on the toilet pretty much. Fingers crossed it holds.

Severed TSX

Update: The other day after work the car started doing the same thing. Drove it to work and even went somewhere on lunch break. No indication of any problems. After work when I go to start the car I get the exact same thing that was happening before. Yesterday on lunch break I swapped the ECU and ignition with the one I had purchased earlier and also got the same results. At this point I'm at a complete loss. I can only assume there is a short in the electrical system somewhere maybe. Who knows but I suppose I let an Acura dealer take this one over. I've read some of the horror stories about the final bill after a trip to the dealer so fingers crossed.

Severed TSX

After a month at my local Honda dealer with no resolution I had the car towed nearly 2 hrs to the closest Acura dealer. After having the car only one day they had it figured out. When I had the car apart I installed a thermal gasket on the intake manifold and used the Blox stud kit to replace the factory bolts. Well the stud kit uses nylon washers so the intake doesn't get damaged when tightening the included nuts. There also happens to be ground strap on the intake manifold. Basically long story short the ground path was broken which just happens to be the one to the ECU which threw the check engine code pertaining to the open circuit. At this point it seems like it should have just been a common sense thing but when installing a simplistic part like new studs the though of the ground never even crossed my mind. A warning on the Blox packaging would have been a nice heads up. The fix was replacing two of the studs with factory bolts. I suppose you could have probably moved the ground strap somewhere else too. So after lots of $$$ down the tubes, problem solved... lesson learned.

curls

Wow, that sucks! I'd contact Blox and let them know, and also let them know the total bill you encountered due to their oversight.

thoiboi

That's kind of what happens when you install aftermarket parts to your car:

Unintended consequences