02 PR5 Crank, No Start

pcb

The Diagram Dude
:
2002 MP5
Here's one of the pics... There's four pages showing the PCM connector.



I didn't realize the link I posted earlier no longer includes the wiring diagrams..

There was another link posted a short while back that I believe included the wiring diagrams.

Maybe you could find it.
 
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Mazda Protege5
Good news!! I had a hunch that maybe it was the PCM since it was a flashed one from an MP3, so I headed on over to the junkyard and found a 02 PR5 but it was an automatic. I grabbed the PCM anyways and threw it my car and it turned on! Car isn’t idling rough, had to take it for a little spirited drive so it could register everything. Unfortunately my speed tach isn’t working, the parking brake light is stuck on(no, i didn’t forget about releasing the P brake), and the seatbelt light is on. Also the CEL light is on but imma wait on that to see what codes I’m getting. Now onto the technical work and trying to solve these problems ;(
 
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Protege5
Good news!! I had a hunch that maybe it was the PCM since it was a flashed one from an MP3, so I headed on over to the junkyard and found a 02 PR5 but it was an automatic. I grabbed the PCM anyways and threw it my car and it turned on! Car isn’t idling rough, had to take it for a little spirited drive so it could register everything. Unfortunately my speed tach isn’t working, the parking brake light is stuck on(no, i didn’t forget about releasing the P brake), and the seatbelt light is on. Also the CEL light is on but imma wait on that to see what codes I’m getting. Now onto the technical work and trying to solve these problems ;(

I'll sell you a stock manual PCM for cheap.
 

pcb

The Diagram Dude
:
2002 MP5
That's awesome news,..
I can't see any reason why you can't iron out the bugs at this point.

...the parking brake light is stuck on(no, i didn’t forget about releasing the P brake), ...

Check the brake fluid level... If it's not low, check the wiring going to the float switch.
Check the switch and wiring going to your P-brake handle.


... and the seatbelt light is on.

Check the connector under the seat and follow that wire to it's end to check for continuity.
The seatbelt light doesn't do anything but remind you to put your belt on,.. It has nothing to do with driveability.
You can turn the light off by either unplugging or grounding the connector (I forget which)


... Unfortunately my speed tach isn’t working,....

Your ECU and cluster aren't receiving speed info...
If you have ABS the info comes from your wheel speed sensors.



You should get an ELM 327 code reader ($10-$20) and the torque app (free)..
You can read and rub your codes yourself as well as see all kinds of info about your car.
Your probably gonna use it a lot and then you won't have to drive somewhere to get them read.

Is your ABS light on ??
 
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pcb

The Diagram Dude
:
2002 MP5
You may have a fried cluster...
You can test it yourself to see if the gauges are working...

You need to use your door switch to enter the test mode...
If the key reminder dings when you open your door, or if the door ajar light comes on, then your switch is working.

 

pcb

The Diagram Dude
:
2002 MP5
I'm pretty sure it's the same ECU used in both the automatic and manual transmission... It just connects up differently.

I did find this...



It looks like a flashed ECU only works with a manual transmission but I'm still pretty sure the stock P5 ECU is the same for both a manual and an automatic.
 
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Mazda Protege5
Should’ve done a fluid check before hand. Flushed and filled the coolant, and topped off the brake fluid(solved the issue). ABS light isn’t on, and the door ajar light also comes on and key reminder dings. On a side note I drove it to work today to see if it was drivable and it was good for the first 5 miles until a problem arose. I lost power all of a sudden and the car died.(whilst this was happening the dash was freaking out and the gauges were jumping all over the place.) I turned off the car and his strange noise came from inside the dash that sounded like grinding plastic gears or something. It sat on a street until I got off work and it started right back up after getting a jump. 1 mile later it does the same thing. Let it sit, jumped it, and drove it 1 mile at a time all the way home. Noticed it was dumping coolant and realized one of the coolant hoses was deteriorated. Maybe a heat problem would cause the car to shut off and freak out? Thanks for all the input!
 

pcb

The Diagram Dude
:
2002 MP5
Check and make sure your alternator is working.
Check the voltage between the battery terminals,.. It should be around 12 V.... Then start your car and test the voltage again,.. It should jump to around 13-14 V.

A weak battery or drop in voltage can freak out your gauges.

If your voltage doesn't increase, check the control wire for continuity. There is a wire that runs from the ECU to the alternator. If it's bad or broken, the alternator effectively shuts off.



 
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Mazda Protege5
Bad alternator. It read around 6 volts running. Any tips on how to get the alternator out of the super tight spot it’s in?
 

pcb

The Diagram Dude
:
2002 MP5
Did you inspect your control wire for continuity ??

If that wire is bad, your alternator doesn't put out any power.
 

pcb

The Diagram Dude
:
2002 MP5
Most guys remove the cruise control unit and pull it out the top.
I've read that the easiest way is to remove the bolts from the hanger bearing and pull the joint shaft about half an inch out of the transmission (not all the way).
Then the driveshaft wobbles out of the way just enough to wiggle the alt. past it.

The bolts from part #4...

 
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Mazda Protege5
I haven’t gotten around to checking the control wire. These wiring diagrams are kind of confusing to me and they are hard to track to the ECU plug since it has so many damn terminals T-T.
 

pcb

The Diagram Dude
:
2002 MP5
Check the LG/W ( light green with a white stripe) wire from the ECU's big terminal to the alternator.
It's right on the end of the big terminal.

Being as you've already found some bad wiring, it would be smart to check that wire before replacing your alternator.





You could try checking the voltage at that terminal with the car running to get a reading... It should probably be between a few volts and 12 volts.
Probe between the backside of the terminal and ground. Then see if the voltage is making its way to the alternator and check for voltage where it plugs into the alternator.

Doing it this way is difficult because the car needs to be running and that can be dangerous.

The better way to check it is to clip a ten foot piece of wire to one of your leads on your Ohmmeter and check for resistance/continuity.

With the car turned off, unplug the LG/W connector from the alternator and clip the long lead to the connectors terminal... Then go inside your car and unplug the big connector from your ECU and test for resistance across the LG/W wire.
The resistance should be 0 or close to it.

You need to unplug both of the connectors to get your reading or you may get a reading of the circuit it plugs into.... You need to isolate the wire.
 
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Mazda Protege5
Finally got around to working on the car. Tested for continuity on the alternator plug and it was fine so I decided to just swap out the alternator. The car is now up and running and driving perfectly, but I still have one issue. The airbag light is still flashing 6 times periodically and it wont go away. Maybe a problem with the airbag/srs module? Pls help hahah
 

pcb

The Diagram Dude
:
2002 MP5
Looks like your your drivers side airbag module... (or it's wiring)



It's covered in the restraints section of your downloaded service manual.

Read through the section very carefully before you start working on it.
The airbag could be set off easily and you could get really injured.
Play it safe and know exactly what to do before you start.
 

pcb

The Diagram Dude
:
2002 MP5
Tested for continuity on the alternator plug and it was fine so I decided to just swap out the alternator. The car is now up and running and driving perfectly,...

Check the voltage at the battery terminals... It should read about 12 V... Then start your car and check the voltage again. It should jump up to 13-14 V.
 
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Mazda Protege5
Airbag light is off for now. As I was trying to test the horn because I’ve never used it, I must’ve shifted some wires or something because the light is now off. Final problem is the damn speedo and the CEL.
 
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