airman3221

Hey guys!
my car isn't starting anymore for some reason. I have lots of information, so instead of making a long paragraph, here's are the infos in bullets points.

Description:

-Ake system (I think it's the one that comes in the GT trim)

-Both my keys can lock, unlock and can turn on the ignition
-Red key light on dash and immobilizer flashing very very fast blocking me from starting my car

​​​​​Solution attempt:

- Cleaned rear antenna inside the bumpers, but still not working

​​​​​Problem scan and specifications:

-OBD2 scan result: U0100 Lost Communication With ECM/PCM "A"

-According to service manual highlights 2006 p. 09-14-14 (security light), security flashes fast for 1 min and plays a pattern for the detected condition.

Result for WDS or equivalent display: [U2510/P1250] Communication error between the keyless controls module and the PCM

- Problem is intermittent. Dosent work for a few days, but randomly works for a few hours. So I doubt the PCM or the Keyless controls module is fried.

​​​​This pretty much explains what's going on. What do you guys think is going on? I'd really appreciate a heads up!
Thanks!

Loki

iTrader: (1)

Have you had a look at the AKE module plug and the ECU plugs? Anything looseor damaged?

airman3221

Hey! Thanks for the reply!

I tried looking for something wrong around the area of the ECU and the AKE module, but I didn't find anything out of place, tho I'm still new on electric wiring. In the end, I just decided that I'll take it to the dealer and pay whatever money they'll ask me. I don't have the proper tool to really analyze in detail what's going on. I'll at least have a bit of trust on their repair instead of me going in blind trying to solve.

If they ever do manage to fix it, I'll post the results over here so other people can check without having to tow the car to the dealer

Hopefully the repair cost won't be expensive!

Jhavelina

Hey Airman, I have the exact same trouble codes and symptoms that you are describing. Did you ever get it to the stealership and have it diagnosed/repaired?

airman3221

Hey Jhavelina!

The dealership pretty much pushed me away after seeing that it's a RX8. They told me that it's because of low compression that I'm getting electrical issues... lol

Anyways, I did some research on my own and from the codes I've been getting and symptoms I've searched in the FSM, I found out that there's a connection issue with one connector in particular with my ECU (all the module connected to it are giving me codes/symptoms that there's a connection issue between the module itself and the ECU.

So the problem could either be a faulty ECU or bad wiring

Vacation is coming up soon, so I'm planning on tackling the issues then.

Hopefully it's just a bad ground or something!

Left4Dead

Just making sure you have you seen this

Immobilizer System (DTC Inspection)

1. Turn the ignition switch to the ‘ON’ position
2. Verify the security light state.
   • If there are any malfunctions:
     • After any malfunction is detected, the security light will function as follows for approximately 1 min.
       DTC 16 and lower: Flashes
       DTC21 and higher: Illuminates
   • If there are no malfunctions:
     • The security light illuminates for approximately 3 seconds and goes out.
3. When any malfunction has been detected, read DTCs via flashing patterns displayed after the security light flashes or illuminates for approximately 1 minute.
   • A verified DTC is flashed 10 times repeatedly by the security light.
   • If multiple DTCs are verified, the security light displays only the smallest DTC.

DTC Table (Immobilizer System)
Security light flash pattern:
∩__∩_________ = No detected communication with the coil
∩__∩∩________ = Coil malfunction
∩__∩∩∩_______ = The key ID number data cannot be read or key ID registration error
∩__∩∩∩∩______ = The keyless control module cannot read key ID number data normally
∩__∩∩∩∩∩_____ = The keyless control module has detected unregistered key ID number
∩__∩∩∩∩∩∩____ = Communication error between the keyless control module and the PCM (no response or mismatched conditions)
∩∩__∩_________= Only one key ID number is registered
∩∩__∩∩_______ = Communication error between the keyless control module and the PCM (data transfer error)
∩∩__∩∩∩______ = ID number data in the PCM and the keyless control module do not match.
NOT ILLUMINATED = Keyless control module malfunction

airman3221

Yep Left4Dead, I've seen this already, but thanks for posting this!

Jhavelina

This is a long shot but it fixed mine. I read a different post about someone pushing in PCM relay in the fuse box and the car would start. Instead of trying to track down a poor connection from the keyless module to the PCM I decided to look into the fuse block itself. After removng every relay and fuse I pulled the entire fuse block assembly out of the box it sits in. Easy to do. Just push the retaining clips aside and lift it out. Turn it upside down and you will see the bus bars that power one side of the relays and fuses. The one that goes to the 120 amp main fuse is the one that was bad on mine. Loosen the small bolt that holds the fuse and pull the bus bar out of the fuse block. Three slots that the fuse "legs" push into from had spread out and were not making good contact. After sqeezing them back together and reinstalling everything has worked fine. It has started flawlessly for over two weeks now. I wish I had taken pictures.

airman3221

Hey! Thanks for the reply!

I think I understand what happened in your case and I'm ready to try it with my rx8. Before I do it, can you give me a description of the issue that was happening in your case and what codes you were getting?

If your description matches mine, then it might be worth to try your solution.

Jhavelina

The history of my issues. Bought the car as a non runner. First thing I checked were fuses due to a non start issue. Dash lights worked but no radio, sunroof, windows, locks etc. Found the main 120 AMP fuse had fatigued and cracked. It did not burn. Was making enough contact to light the dash but nothing else. Changed the fuse and car started right up. Three days later it died while driving down the freeway. Luckily I was near an off ramp and I was able to coast up to the intersection and push it through to the other side. When trying to restart the red key would flash and the starter would not engage. Everything else in the car worked. Radio, sunroof, lights etc. Sat for about 10 minutes while letting people know that I was broke down and would be late. Opened fuse box and checked fuses. After that the car started right up. Drove home and parked it. Two days later I had it smogged and went to the MVD to transfer the title. Up until that time it started fine 4 times. After coming out of the MVD it would not start. Same flashing red key on the dash. Opened the fuse box and wiggled the fuses and it started right up. Drove home and checked the trouble codes and came up with this.

∩∩__∩∩_______ = Communication error between the keyless control module and the PCM (data transfer error)

It made sense to me that if the PCM or any other module was not getting the power it needed, it could not communicate with anything very well. Checked for voltage on the top side of each fuse while wiggling them and found #27 would go to zero and back up to over 12 when moved. Flipped the fuse block over, removed the bus bars and found the spread fingers. Bent them back, installed the fuses and it has been fine since. Over 300 hundred miles and dozens of start ups. The fuses that were not making good contact were 25,26 and 27. Horn, hazard and ETV. 27 was the worst by far. These are obviously not directly related to the PCM but the way Mazda laid out the electrical circuits in this thing the PCM seems to get power from many different places.

airman3221

Interesting...

So you mean that the PCM is not getting enough power because of bad connection around the fuse box, which leads me having intermittent issue?

Also, the issue you're having is a bit different than mine, but the "intermittent" part is really similar. I'm thinking it wouldn't hurt to try

Jhavelina

That is what it seems to be. I would not have thought about it had I not read a previous post from another owner. The immobilizer would not let his starter engage along with the flashing red key on the dash. He had a friend try to start the car while he pushed down on some of the relays in the fuse box. As soon as he started putting pressure on them the car started. After it worked twice on my car, I tore into the fuse block and found the bad bus bar. It costs nothing but an hour of time to check them all out.

Jastreb

iTrader: (1)

Subbed for similar issue.... Good idea to check the fuse box connections.

airman3221

Hey Jastreb!
I'm curious on what kind of issues you are facing. Can you give a brief description of what's going on and what codes you're getting?

LGJmissionks

Hi All,
I have a 2006 RX8. I haven't had problems for years, but yesterday I tried to start it and it wouldn't start.
Description:
-Both my keys can lock, unlock and can turn on the ignition
-All the dash lights come on and the battery is good
-The immobilizer light is flashing blocking me from starting my car
After trying to reset the ECU by disconnecting the battery and pumping the brakes, the immobilizer light still flashes and it won't start.
However, after several tries, it finally started so I drove it home and then tried to start again, but back to the immobilizer light flashing with no start.
I did the OBD2 scan and it showed no codes.
Anyone have any ideas before I take it to the dealer?

airman3221

Hey LGJmissionks!

Can you tell me what pattern the immobilizer flashing gives? Here's how to check:
Immobilizer System (DTC Inspection)

1. Turn the ignition switch to the ‘ON’ position
2. Verify the security light state.
   • If there are any malfunctions:
     • After any malfunction is detected, the security light will function as follows for approximately 1 min.
       DTC 16 and lower: Flashes
       DTC21 and higher: Illuminates
   • If there are no malfunctions:
     • The security light illuminates for approximately 3 seconds and goes out.
3. When any malfunction has been detected, read DTCs via flashing patterns displayed after the security light flashes or illuminates for approximately 1 minute.
   • A verified DTC is flashed 10 times repeatedly by the security light.
   • If multiple DTCs are verified, the security light displays only the smallest DTC.

DTC Table (Immobilizer System)
Security light flash pattern:
∩__∩_________ = No detected communication with the coil
∩__∩∩________ = Coil malfunction
∩__∩∩∩_______ = The key ID number data cannot be read or key ID registration error
∩__∩∩∩∩______ = The keyless control module cannot read key ID number data normally
∩__∩∩∩∩∩_____ = The keyless control module has detected unregistered key ID number
∩__∩∩∩∩∩∩____ = Communication error between the keyless control module and the PCM (no response or mismatched conditions)
∩∩__∩_________= Only one key ID number is registered
∩∩__∩∩_______ = Communication error between the keyless control module and the PCM (data transfer error)
∩∩__∩∩∩______ = ID number data in the PCM and the keyless control module do not match.
NOT ILLUMINATED = Keyless control module malfunction