Thanks guys for your thorough and helpful responses, I very much appreciate your time and efforts here in assisting me troubleshoot my car (I REALLY WANT TO DRIVE IT!!!)

Just a couple notes, I have already thoroughly cleaned the battery - + connectors and shunts and applied some light vaseline to keep them from corroding in future. Also there is no dirt, water, corrosion in the black box where the RCM is housed, all connectors and bays are very clean in my car.

As suggested I am going to check some of the other suggestions you guys made, probably with my mechanic as I am a little hesitate/scared to touch anything when battery is connected or engine idle.

 

No need to thank us, just let us know where to send the invoices!

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Need a little guidance with the electrical problems that everyone seems to have with this car. Car is with my son in LA and only comes to visit when its acting up. Engine stumbles and sometimes stall after driving for trips to and from work. Every time but once it started right up. The time it didn't start right up, it took 2 to 3 minuets to kick over. It sometimes dies when the sub amp is blasting and also when the windows are opened or closed. It is now in my garage and I cant get it to stall only stumble and the BAS/ESP light comes on.

I have re-soldered the rcm at lease 6 times in the past year just to make sure its not the problem.
Battery voltage is 12 after sitting for 4 days. Charging volts is 14.4.
MAS was changed out 6 months ago thanks to advice from the CFF.
Changed the cam sensor at the same time

Just checked the battery cables and the negative cable is full of corrosion. Cut it back 4 inches and its all white powder inside. Can this cause all the problems. Has good voltage to fuse box. How can I check amps and how many amps should it produce.

 

Alright, so I've been getting the P0410 code frequently for a couple years and have just been cleaning the burnt contact on the RCM over and over. I finally noticed that I can feel air coming out of the pump at the front of the engine. I assume that's probably why the contact is getting burnt repeatedly? And I take it I probably just have to replace the friggin pump?

 

Hey all,

I've got a massive problem! My car was working intermittently and was switching off completely unable to start (cliche problem). However I performed to above tutorial and now my car doesn't start at all!!! It sounds as though its trying to kick over but the engine is not starting! Any help would be greatly appreciated!

 

Have you tried a new crank position sensor?

 

No I havnt, however I am more worries about the fact that I may have somehow ruined my RCM? The car has been running fine for the past few months, although I have been getting the engine light coming on and a P0410 error, and I can along this thread and decided to see if my RCM soldering had become worn. This proved to be true, so I resoldered the joint and now I have this problem? Is there any way of knowing if I have somehow damaged my RCM?
Your help is really appreciated!!!

 

When it died did it spin the engine when trying to start? That is the CPS.. Your code could have been from the RCM. If it was and still is spinning with the starter I'd address the CPS and go from there.
I don't know of any DIY method to test your RCM.

 

Just checked the battery and it was very low, so I charged it and walah, it turns over! Now to move onto that pesky BAS/ESP light, grrrr

 

Btw, thank you Mrmiata. A few months ago I had that exact problem you described. I left it for a few hours and then it started working again. With the CPS, why does the component fail? I'm just asking this because if cleaning/any maintenance will help I'll do it now. Also, does this make you suspect it was my RCM or the CPS that was my original problem?

 

I'm thinking you might have both.. with the code and bad joints on RCM .. and with it dying.. will crank at starter - starts when cooled off says CPS. Guess they are just one of those things that aren't built rock solid.. Miata has close to 200k on her and OEM CPS. No maintenance or anything is going to prolong it's life cycle. Just go Bosch as your best safety net against failure. I will say my advanced auto version has held up so far... almost a year now.. but it does have a lifetime warranty with it. Bosch is on board as spare for peace of mind and emergency fix.

 

If you find something let me know! After changing wheel speed sensors I'm just waiting on divine intervention

 

Just wondering if anyone has "limped" the car home by putting some foil tape or something on the faulty RCM connections. My car is "mystery no starting" in a parking lot 10 miles away from my house and I was hoping to not leave it overnight or have to pay for a tow to put in my driveway until I can get the RCM soldiered (assuming that is the problem).

Anyone have any success with a temp fix on the RCM?

Thanks

 

Sorry, but foil wouldn't help - and might make it worse by causing a short circuit. You could try shaking the car to see if the contacts bump enough to allow it to work briefly, but I wouldn't plan on that working.

 

Thanks Magneticred,

Do you jknow if I hit the box the relay is in and it starts, will it stay running or will it possibly leave me stranded 1/2 way home if I get it started?

 

The RCM also provides power to the fuel injectors, camshaft position sensor, and other important items, so I suppose your car could stall if it is successfully started.

 

I've had a similar issue for a while now and I finally got a soldering iron so I could fix the RCM and the connections looked fine. Hooked it back up and car ran fine for 2 days. This morning it was acting up again so I just unplugged it for a second and now it's fine again.

 

Do you have a good battery with solid connections and good ground connection & alternator giving correct voltage. I had a truck that when the battery was dying (low) it would act really funny like only start and stay running while I had the accellerator pressed down and as soon as I let it up the thing stalled out.

 

FYI - I did limp the car home by hitting the top of teh RCM while getting my wife to crank over the car and it started right away and got me home. Took out the ppart and soldiered the points that were bad and have had no issues since.

PS - I ordered an extra RCM anyways before I got the car fixed so I have a spare one now.

 

Got the "Check Engine" light yesterday on the SRT. Hooked up my Actron Auto Scanner (p/n CP9575) and got the P0410 code. I had done the RCM fix on the Limited but not on the SRT so out comes the board. Sure enough, broken solder points...

DSC00027.JPG

I have an old WL Lenk BP100 cordless soldering iron that hasn't been used for a couple of years. Gave it about 2 hrs to charge and it did the job. Just kinda blobbed on an oblong ball of solder that covered each set of contacts but made sure not to make connection between each of the other 2 point sets, which also got blobs.

Slid the RCM back in and started her up. No more Check Engine light. Even solved my hesitation when I accelerated from a dead stop. And I didn't need to disconnect the battery.

I did also sprayed down the relays with some Miller-Stephenson Safezone Contact Re-NU (MS-930/C02) just in case any one of them was sticking.