New to P5 Auto Tranny

pcb

The Diagram Dude
:
2002 MP5
It is the same ECU. It's only the wiring harness and instrument cluster that are auto specific.


I didn't know the cluster was automatic specific.


, and then wire the clutch pedal switch directly to the starter switch.

Don't forget, there are two clutch switches.




All I have left to do is try and make some resistor packets to match the resistances of the solenoids to get the CEL to go off.

Do you think that a cluster from a manual would avoid the resistor trick ?


I can post a complete re-wiring guide here if you all think that would be beneficial to anyone.


I would certainly be interested.

Maybe talk to Antoine and he can put it in the how-to section?

(there's still a few of us holding on to our old cars.)
 

Mikeyman64

Zoomer
:
Atlanta
:
2002/2003.5 "MSP5"
"I didn't know the cluster was automatic specific."

Yes, it has the LCD on the left that shows the gear you are in. This is also a 2003 with the shifter mode transmission.



"Don't forget, there are two clutch switches."



Yeah, I meant to say the two wires. I think the second switch is tied to the same circuit as the neutral switch? It should be the same as far as I know.



"Do you think that a cluster from a manual would avoid the resistor trick ?"

Yes, it probably would, but the odometer is cluster specific and there is a 130k like discrepancy between the two I have.




"I would certainly be interested.

Maybe talk to Antoine and he can put it in the how-to section?

(there's still a few of us holding on to our old cars.)"

I'll write something up and PM him.
 

pcb

The Diagram Dude
:
2002 MP5
Yeah, I meant to say the two wires. I think the second switch is tied to the same circuit as the neutral switch? It should be the same as far as I know.


I think they might be separate?

The starter interlock is more of a power wire, while the other might be more of a signal wire?

There are two separate switches.
It might be for a reason?
 

Mikeyman64

Zoomer
:
Atlanta
:
2002/2003.5 "MSP5"
I think they might be separate?

The starter interlock is more of a power wire, while the other might be more of a signal wire?

There are two separate switches.
It might be for a reason?

I'll certainly investigate more before posting anything. I think you're right.
 
I think they might be separate?

The starter interlock is more of a power wire, while the other might be more of a signal wire?

There are two separate switches.
It might be for a reason?
There are three switches in manual trans boxes; Clutch-starter interlock, Neutral switch -tells the ECM that car is in neutral and adjusts engine operation accordingly- and IF it has cruise control, a CC disconnect switch. All three are separate circuits.
 

pcb

The Diagram Dude
:
2002 MP5
There are three switches in manual trans boxes;...
I meant that there is two separate switches on the clutch pedal itself.

One is the starter interlock and the other runs to ECU as well as the CC module.

There is also a reverse switch in the transmission but I'm pretty sure that just turns the reverse lights on and off.
 

Mikeyman64

Zoomer
:
Atlanta
:
2002/2003.5 "MSP5"
I meant that there is two separate switches on the clutch pedal itself.

One is the starter interlock and the other runs to ECU as well as the CC module.

There is also a reverse switch in the transmission but I'm pretty sure that just turns the reverse lights on and off.

I had wired the "Neutral switch" incorrectly at first and it caused some issues, so I cut the wires. Now I can't seem to detect any difference in the car's drive-ability with the wires to the neutral switch cut. I need to test it out with CC before I ignore it. It may be 100% CC related.
 

pcb

The Diagram Dude
:
2002 MP5
You're probably gonna pop a code.











And it's probably not a good idea anyway.

The ECU needs to know if you're engaged and in gear.



When you push the clutch, the ECU needs to know to go to idle.
 
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Mikeyman64

Zoomer
:
Atlanta
:
2002/2003.5 "MSP5"
You're probably gonna pop a code.











And it's probably not a good idea anyway.

The ECU needs to know if you're engaged and in gear.



When you push the clutch, the ECU needs to know to go to idle.
Yeah, I plan to fully wire it correctly. I was just giving some information about what I noticed.

Before I get it inspected (apparently there is a 30-day wait due to C-19-19 for some reason) I plan to correctly wire the neutral switch and then install some resistors to turn off the CEL for the auto solenoids.
 

i12drivemyMP5

___ 323F ___
Contributor
I have a manual trans gauge cluster if you're interested in it....Not sure what mileage is on it...bought it as a spare or project or something because I have sportronic. I have no use for it.
 

pcb

The Diagram Dude
:
2002 MP5
On a 20-year-old car, the mileage is almost irrelevant.

If it lived to be twenty, it must have been properly maintained.

Our cars can go over 300,000 miles even on the original clutch.
 
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pcb

The Diagram Dude
:
2002 MP5
"Do you think that a cluster from a manual would avoid the resistor trick ?"

Yes, it probably would, but the odometer is cluster specific and there is a 130k like discrepancy between the two I have.
It sounds like he already has a manual cluster. He's going to install resistors to make the automatic cluster work.

I think he should just install the manual cluster. He says he's going to give the car away anyway.
 

Mikeyman64

Zoomer
:
Atlanta
:
2002/2003.5 "MSP5"
It sounds like he already has a manual cluster. He's going to install resistors to make the automatic cluster work.

I think he should just install the manual cluster. He says he's going to give the car away anyway.
Correct. I have a manual cluster. I just wanted to try and keep the original odo reading since it only has 130k miles on it.

But it is proving to be a pain in the butt to get it to work 100%, so I'll probably throw in the towel and use my old manual cluster.
 
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Mikeyman64

Zoomer
:
Atlanta
:
2002/2003.5 "MSP5"
So I ended up swapping out my old manual ECU with the auto one as well as the instrument cluster, based on a good P5 expert friend's advice (the ECUs are in fact different).

Now I'm seeing an odd issue where the engine jumps up to an idle of 2k rpm on a cold engine and about 1500 on a warm engine only when the clutch is in AND the car is in gear (e.g. neutral switch related).

Image below of the rewire I made:

trannywire.PNG


I'm gonna dive into it some more after the holiday, but I'm pretty sure some additional rewiring needs to be done with the harnesses...
 
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