420A No spark, Ignition Control Module?

[shaunsy12]

I have no spark after replacing the ignition coil could the ECU have gone out even though the fuel pump comes on I've done replaced the coil pack fuel pump and filter crank sensor someone please help me out with this

 

[shaunsy12]

The 30a fuse looks good but how can u tell its bad if the metal bar is broken and ill try what you had given me

 

[luv2rallye]

You can only completely tell it's bad by removing it and checking for continuity across it since it can have a hairline crack that you can't see. Or if you don't want to remove it you can do this: http://www.dsmtuners.com/forums/articles-electrical-wiring/179914-fuse-testing-without-removal.html.

 

[bryanwheat]

Being that you already posted a thread pertaining to this, http://www.dsmtuners.com/forums/newbie-forum/432827-ecu-programming.html . I will tell you again, buy a multimeter, learn how to use it and go to work. Stop throwing parts at it.

 

[luv2rallye]

buy a multimeter, learn how to use it and go to work. Stop throwing parts at it.

Agreed. How to use a multimeter: http://www.dsmtuners.com/forums/articles-electrical-wiring/404574-multi-meter-usage-primer.html.

 

[shaunsy12]

What are the voltage readings suppose to be do u know or have a website that could help me out

So how would the asd relay go bad is it heat sensitive or is it just from wear and tear

 

[luv2rallye]

Wear and tear but measure voltage on it before assuming it's bad.

 

[bryanwheat]

Testing voltage is only half of what you need to do. The multimeter also has a continuity setting which test's for a complete circuit. You need to test the wires from the ecu to the coil pack to see if there is a short, and test for a short to ground also.

 

[shaunsy12]

Well I measured the voltage to the coil and it had no voltage

 

[bryanwheat]

You tested the black wire with the red stripe right? According to the schmatic in the chilton manual the power wire comes from a junction box that is powered by the ignition switch. This same junction also powers everything in the engine bay and the ecu. I assume that this junction is in the fuse box but i don't have a 420a car in front of me so i can't tell you exactly where to look. Someone will chime in who knows though.

 

[shaunsy12]

I tested all three wires any which way I could've possibly done

I'm gonna double check it tomorrow I was kind of in a hurry to eat and get back to workso after i double check myself I will let y'all know so i can find out what to do next

OK so I double checked my coil connection and i have no voltage but I get resistance out of it what else should I do

 

[DSM Solar]

I'm going through the same situation with my 97 420A, I was driving and all of the sudden the car turned off. I'm also getting a no spark at the coil pack. I'm going to try the VSS, I just replaced the ECU, and still the same situation. I read in the Mitsubishi manual that the power transistor on the 420A is actually in the ECU. Hope to hear something soon. I will post anything further that I find.

 

[shaunsy12]

Well I myself have already replaced the vss and still not getting anything so i have to check the voltage at the coil and see if the asd relay is bad that's where I'm at right now with mine I suggest you try the same before blowing anymore money on parts

 

[luv2rallye]

With a multimeter always test voltage using the + (red) lead and the - (black) lead connected to the chassis bare metal (or battery negative).
So with the key to ON (not Start) you don't see voltage on the coil's black-red wire (you can unplug the coil for this)?

If not then test the black-red wire on the ASD relay - 22b here: http://www.dsmtuners.com/forums/attachment.php?attachmentid=23588&d=1075582725. There are also a red-black wire and a black-white wire on the ASD relay that should always have power on it (otherwise 30A fuse is probably blown). Verify this.

The PCM (ECU) activates this relay by putting a ground on the ASD's red-white wire. The relay should then connect the red-black to the black-red (that goes to the coil). Key on. Test voltage on the red-white. If +12v the PCM is not grounding this wire. Try touching a wire on the red-white's ASD terminal to ground - the relay should activate (and put +12V on the black-red). If so the relay works and your PCM is the problem. If it doesn't activate (and you had +12v on the red-black) the relay is the problem.

 

[shaunsy12]

OK with either ECU I have I get voltage to all the wires but the red-black wire

And with the red-white wire you take the negative lead to that and the positive lead to the red-black wire??

 

[luv2rallye]

And with the red-white wire you take the negative lead to that and the positive lead to the red-black wire??

No - to test the ASD relay you take a piece of wire and connect one end to bare metal chassis (ground) and touch the other end to the ASD relay terminal that has the red-white wire on it. Leave the relay connected when you do this but you can leave the key off for this test. When you touch the terminal the relay should activate (hear a click) and you should see +12v on the black-red wire (one that had 0v before).

Voltage is ALWAYS measured with the multimeter's black (negative) lead connected to bare metal chassis (ground). You just move the red (positive) lead to the spot you want to measure voltage at.

Notice there are 2 different black/red wires on the ASD relay. One is black-red (black with a red stripe/marking) which goes to your coil (and also to PCM pin 6). This is the one you said has no voltage on it at the coil. The other is red-black (red with a black stripe/marking) which goes to the 30 amp fuse (and also to ASD relay black-white wire) and it (they) should ALWAYS have +12v on them.

 

[shaunsy12]

OK ill try that in a little bit and see what the outcome is

So i grounded the relay and the black-red wire got voltage to it

 

[shaunsy12]

So its off to the mechanic my car goes tomorrow

 

[luv2rallye]

So i grounded the relay and the black-red wire got voltage to it

So you put a ground on the ASD relay's red-white wire (with relay connected), heard/felt it activate (click), and then saw +12v on it's black-red wire (not the red-black or black-white which always have +12v on them), when you didn't have voltage on the black-red before the relay activated - correct?

If yes, recheck the coil's black-red voltage when you force activation of the ASD relay again. You previously said there was no voltage there. Is there voltage there now when you are forcing the ASD relay activation?
...If yes, suspect the PCM not activating the ASD relay.
...If no, you have a connector or wiring problem. This type of problem is usually in or close to the connectors so check them at both the ASD relay and the coil. Move the wires going into each connector around to check for breaks while measuring voltage at the coil connector to see result (or you can unplug both and do continuity test while moving wires). Also make sure the connector pins lock in place so they don't get pushed back when connected.
......If that's ok, you have a wire break between the ASD relay and the coil. Visually inspect the wire harness between the two for possible breaks/damage. Move harness around while checking voltage at the coil. If can't find anything you will have to unwrap harness and do continuity test of wire while moving it around. Be aware that the ASD relay's black-red also goes to the injectors, both O2 sensors, noise capacitor on valve cover, alternator, and PCM so it may go to any of these before reaching the coil and the problem may be there (so check voltage on each before unwrapping any harness.

 

[shaunsy12]

OK ill have to try that

 

[shaunsy12]

OK I've got the car running and now I've run into another problem.. I do believe the speedo pinion has fallen into the transaxle what is the easiest way to remove the pinion from the transaxle