420A Where can I get PCM for 95 manual?

[3Starsearch]

I'm having no communication with my PCM when I plug the OBD2. No power to crank and cam sensor including ignition coil. Replaced the fuel pump and MFI/ASD relay nothing works. I got power for MFI connector(I hear no click) but nothing for fuel pump. I have ground, my last guess is to replace the PCM. Not too long ago I had a code for P0351 and almost 2 weeks ago my car suddenly died and had to tow it home. Checked junk yard, eBay, marketplace part out nothing. Is rock auto a good place and which one?

I forgot to mention, I used another PCM but still no communication. Not sure if that was faulty as well. Im cooked rn

 

[chrysler kid]

You can find the factory service repair manual online for free at www.charm.li

The used parts place we typically refer people to is Miller Import Parts which is now Kannapolis Auto Parts on Facebook. The owner Steve Miller collects as many salvaged DSM’s as he can get ahold of.

Does the starter engage and turn the motor over? If it’s cranking with the starter does it sound normal or is it much faster and higher pitched?

If the starter is not engaging there could be other wiring problems under the dash from the steering column, or could be as simple as the clutch pedal switch being broken and not letting you start the car because it doesn’t think the car is in neutral with the pedal pressed

 

[chrysler kid]

Have you used a volt meter to verify that the fuel pump is not receiving a 12v power signal? Can you please verify before rewiring that the fuel pump has not gone bad?

From sitting a long time the fuel pump could have gone bad from contaminated fuel. It’s possible that the ecu is still sending 12 volts to the pump but the pump has gone bad

 

[3Starsearch]

Have you used a volt meter to verify that the fuel pump is not receiving a 12v power signal? Can you please verify before rewiring that the fuel pump has not gone bad?

From sitting a long time the fuel pump could have gone bad from contaminated fuel. It’s possible that the ecu is still sending 12 volts to the pump but the pump has gone bad

My neighbor did a bypass for me to isolate the fuel pump whether it works or not. Which it did since it was only last year since I replaced it. Although I don’t remember seeing if I used a multimeter to check if it’s getting 12 volts

 

[chrysler kid]

Ok just checking because it could be as simple as the fuel pump went bad because the car was sitting so long

 

[jesse12345]

So my buddy did a rewire for the fuel pump on the car I currently own which is an early 95 rs and it worked for awhile. Eventually it wouldn't start so I swapped an ecu I had laying around and it fired up so I wired everything back to stock and never had an issue again. I'm not saying to go buy an ecu because the 95 and 96 ones aren't cheap even used but I'd definitely test everything first. I'm wondering if that gel they use inside does more harm then good.

 

[3Starsearch]

Changed the ignition switch absolutely nothing happened. Will still try to continue to figure out this problem. I’ll keep everything updated.

 

[3Starsearch]

I wanna make sure if my PCM is outputting what it needs. My car has been down for over a month and came to one of the conclusion that it maybe a faulty PCM.

Context: Went to go eat dinner with some homies late at night. Got done and got in the car for it to not start but it cranks. Last thing I remember that day was replacing a negative terminal. Towed it home to inspect. My terminal is fine, got good ground overall in sensors and most of my PCM pins. Replaced both crank and cam sensors nothing changed. Found out that it doesn’t get spark and fuel including not getting power to cam and crank sensors. I get BOTH power & ground to ASD/MFI & Fuel pump relay. Traced it PCM, for ASD/MFI Pin 2 I only get ground and Pin 58 I have power and 12v. I didn’t have the chance to check power/ground/voltage to fuel pump pin. Since it’s really compacted, need to cut the plastics, supposedly it’s pin 38. My fuel pump works since I used a 12v battery to bypass it.

Another thing is no power to overall ignition system, coil pack, injectors, fuel pump connector, CEL doesn’t illuminate, no communication with PCM with OBD2, fuses are ALL GOOD.

Found a 95 Eclipse RS manual trans part out, bought a supposedly working PCM to see if anything happens. Hopefully.

If anyone got similar experience I’d like your input please. A common thing I see from forums is to disconnect ALL COMPUTER SENSORS one by one to see if communication returns that may just be a shorted sensor/wire that brought down the whole connection. Or what they say to check the 5v reference sensors.

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[3Starsearch]

I have a 1995 Mitsubishi Eclipse RS NT. O'Reilly doesn’t match the numbers, Rock Auto has them but not in stock. I’m not sure if this is OEM. Couldn’t get a hold of a Mitsubishi dealer if I could verify the part

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[3Starsearch]

Got a PCM problem. For 1995 Eclipse RS Manual. Pin 4 (Y) Power to Crank/Cam/Speed Sensor. Back probing I only get ground, including battery voltage from back probe and positive terminal. Does it mean PCM shorted out? I also only get ground for Pin 3 (G-Y) Power to TPS/MAP sensor. I also don’t get CEL nor any communication with PCM.

 

[steve]

I pulled your other posts together so people can see the history. This is better that many little ones because you loose focus and whatever attention you had along with the background.

I'm not very informed with how the 420A PCM and MFI electrical works but looking at the diagrams, power from Fusible Link #4 goes to the ASD Relay pin 8 (Large Red/Black) and is switched to the output on pin 2 (Large Black/Red) when the PCM pulls it's pin 58 (Red/White) to ground.

The switched power goes into J/C (3) and feeds to PCM pin 2, the ignition coil pin 2, the front O2 Sensor pin 4, the rear O2 sensor pin 3, all of the injectors pin 2, and the generator.

It also looks like the PCM gets woken up from the ignition switch (IG1 Large Black/White) to PCM pin 14. That same signal is also connected to the EGR Solenoid pin 2, the "Asperator" Solenoid pin 2 and provides power for the coil of the fuel pump relay. Power for the pump comes from the same fusible link that powers the ASD relay. The FP relay is controlled by the PCM pin 38 (White/Red)

PCM pin 51 may be the source of backup power for the PCM. It shortcuts the ASD relay and runs direct to Fusible Link #4.

Until you see power at PCM pins 51 and 2 I wouldn't expect to see voltages present for any of the sensors (either the 5v or the 9v ones)

From https://www.dsmtuners.com/threads/2gnt-1995-rs-gs-esi-420a-mfi-wiring-diagram.536165/

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[3Starsearch]

I pulled your other posts together so people can see the history. This is better that many little ones because you loose focus and whatever attention you had along with the background.

I'm not very informed with how the 420A PCM and MFI electrical works but looking at the diagrams, power from Fusible Link #4 goes to the ASD Relay pin 8 (Large Red/Black) and is switched to the output on pin 2 (Large Black/Red) when the PCM pulls it's pin 58 (Red/White) to ground.

The switched power goes into J/C (3) and feeds to PCM pin 2, the ignition coil pin 2, the front O2 Sensor pin 4, the rear O2 sensor pin 3, all of the injectors pin 2, and the generator.

It also looks like the PCM gets woken up from the ignition switch (IG1 Large Black/White) to PCM pin 14. That same signal is also connected to the EGR Solenoid pin 2, the "Asperator" Solenoid pin 2 and provides power for the coil of the fuel pump relay. Power for the pump comes from the same fusible link that powers the ASD relay. The FP relay is controlled by the PCM pin 38 (White/Red)

PCM pin 51 may be the source of backup power for the PCM. It shortcuts the ASD relay and runs direct to Fusible Link #4.

Until you see power at PCM pins 51 and 2 I wouldn't expect to see voltages present for any of the sensors (either the 5v or the 9v ones)

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Thank and I apologize for this big mess as I’m still trying to get accustomed to DSMTuners. I checked everything here with the ignition “ON”. It should’ve powered the fuel pump to prime but as of right now it didn’t. Verified I have good ground for the sensors and the PCM, the power supply is supposedly is Pin 14 and 51. I get it from there and getting battery voltage. Pin 3 & 4 that’s suppose to be powering these sensors are the opposite(ground). Would this be a high chance on ruling out a bad PCM?

 

[steve]

I checked everything here with the ignition “ON”. It should’ve powered the fuel pump to prime but as of right now it didn’t.

Verified I have good ground for the sensors and the PCM, the power supply is supposedly is Pin 14 and 51. I get it from there and getting battery voltage. Pin 3 & 4 that’s suppose to be powering these sensors are the opposite(ground). Would this be a high chance on ruling out a bad PCM?

Like I said before I believe pin 51 is the unswitched backup power. That's used to retain long term data like faults and fuel trims.
Pin 14 looks to me used to tell when the ignition is turned on but not as a source of power. I still believe pin 2 is where the PCM draws it's operating power from.

Pin 3 looks to be the 5v sensor power for the TPS.

Pin 4 looks like the 9v power for the Cam, Crank, and VSS sensors but they signal using 5v pullups (a resistor to 5v to limit the current so the other end can pull it low).

Pin 10 is the signal that you're trying to start the car from the ignition switch.
Pin 11 is sensor ground.
Pin12 is the PCM ground.

I'm not seeing pins 22 or 42 in the diagram even though you list from 2GNT says their are grounds.

Since you and I don't agree on where the power comes from I can't support any conclusions yet.

 

[3Starsearch]

Car runs, bought a new PCM from rockauto. Cardone and it fired right up. Although I have a check engine light for an air pump. Even though it had a recall in 1998 to remove it. Anyone know what I can do?

 

[jesse12345]

It sucks that the 95 and early 96 talon/eclipse have these pcm problems. I see now people are charging heavy prices for them. I had only one spare lying around because mine also clapped out so I'm getting a little nervous.
Glad you got it all figured out.

 

[3Starsearch]

It sucks that the 95 and early 96 talon/eclipse have these pcm problems. I see now people are charging heavy prices for them. I had only one spare lying around because mine also clapped out so I'm getting a little nervous.
Glad you got it all figured out.

I agree I had a code from 6 months ago that correlated to ignition issue because it would die randomly during idle sometimes mid drive. It was a P0351 I believe, even changing spark plug, wires, coil pack, both crank and cam sensor didn’t change. Code kept coming back and I thought it was weird, now I realize the PCM was slowly close from completely being dead.