rreign

So here's the deal. I'm driving an 04 GT with 68000 miles. I drove about 25 minutes away from my house, parked and picked up my wife's car for her. (we just had a baby) The car sat over night and I went to pick it up the next morning and it tried to turn over but it just wouldn't start. (a few days before the incident the car lagged when starting, but it still started) I put it on a trailer, brought it home and checked just about everything I could think of. I replaced the battery and spark plugs, I can smell gas and hear the fuel pump start, all the lights work, all the fuses are good, it sounds like it is starting to turn over but it just won't. I checked the diagnostics comp I have and it found a code ( U0121 ) which is saying it "Lost comm. with ABS Module" can anyone tell me what the problem might be? I'm getting really frustrated and I'm trying to avoid having to take it to the dealership being that I am not under warranty anymore. Any help would be great.

DarkBrew

So the starter is turning the engine over and there's some ignition but it does not start. Right?
Have the coils been checked/changed?

I think that the lost comm error happens because the battery was disconnected. Clear that code and the next start it should be gone.

rreign

I haven't checked the coils yet, that was my next step but I wanted to get some advice first. I erased the code and reset my ECU and I haven't seen it come up since. I just can't seem to figure it out. I got no CEL on or anything.

Mike06

LOL!

boy am i glad that i still have my warranty !

son, you got owned.

the stig

how do you check the coil? where is it located?

Mike06

pwned.

nycgps

iTrader: (1)

Is a group of 4 *black-ish* thing that has 4 big wires connected to the top of it, its located under your Intake Tube.

Old Rotor

Here is the coil check procedure.

http://www.finishlineperformance.com...16-07-1793.pdf

Startl_Respons

Huh?

Startl_Respons

At your mileage, I bet it is the coils. They cost about $30 each. Maybe you can get them for $28 each. There are 4 of them. Every RX8 will eventually need coils replaced because Mazda gave us ones that can not withstand the heat in the engine compartment. There are not any/many alternatives on the aftermarket so you will need to stay with OEM. They're fine, they just don't last much more than 50,000 miles. Mine lasted 90,000 miles and I count myself very lucky.

Remember, you would have to eventually replace them anyway, so you might as well do it now.

rreign

I only have one problem with all this... i cant check the coils properly when i can't get the car started. it's been like 2 more days since i posted this thread and i still cant get it started. i got new wires on the way and im about to order some new coils just for sh*ts n giggles. i figure even if all of this doesn't work, then atleast i did a FULL tune on the damn thing. anyway, if anyone has anymore tips or has had this same problem, keep posting. i can use the help. n when i figure this out im gonna put a new thread up that can help anyone that might run into this problem.

nycgps

iTrader: (1)

You dont need to *check* it or anything.

Just replace them,(coils) its Way over due anyway

Its only about 110 bux, and its something that you can install it yourself easily.

oh forgot to add, if it lost communications with the ABS module. First unplug the battery, replace the coils first, reconnect battery, drive around for 10-15 minutes for about 4-5 times. see if the CEL goes away. if it does not (and your ABS light turns on), you better have the ABS check @ some garage.

agoodcave

After replacing the coils, (but before cranking) you might want to run a deflood procedure just to clear the fuel from the previous failed starts

1. pull plugs
2. pull fuel pump fuse
3. crank engine
4. replace plugs and fuse

Mike