ccrm?

[frcoonhounds]

Checked the fuses again and all are working properly.

I've never used a multimeter before, but today I tested for continuity on the wires from the CCRM harness. With the battery unhooked and the ignition turned to ON I received normal readings from pin 5 which is the power to fuel pump wire. Pin 13, power to PCM relay, had a very high resistance reading, reaching almost 1500. I'm not sure if this shows a bad connection to the PCM, or if I'm testing incorrectly. Also, is the PCM the silver box behind the glove compartment which connects to the wiring harness on the firewall, or is the the blue box on the sidewall with two connectors?

Also checked for voltage. Not sure which wires I should be testing, but with battery plugged in I was getting less than 1v to pin 5, pin 12, pin 13, and pin 24. All other wires were getting 12v

If I did the testing correctly, does this mean I have a bad ground to the PCM somewhere?

 

[frcoonhounds]

Pulled the PCM today and all the pins look fine. Appears the PCM is remanufactured, but not sure if it's the stock PCM or a D4U1. Is it okay to try and remove the plastic tubing around the wiring harness to inspect the wires?

 

[frcoonhounds]

Since I have been getting no spark and no fuel pump prime, I am assuming that the PCM is a possible culprit. Pins 8 and 12 on the CCRM as well as pin 1 on the PCM are currently getting 12v with the battery connected. With the ignition turned ON pin 13 on the CCRM is also running 12v.

As far as I can tell, there are 5 wires running from the CCRM which could explain my problem, those being the 2 yellow wires from CCRM pins 12 and 8 that connect to PCM pin 1, the red wire from the CCRM at pin 24 to PCM pin 57, the pink/black wire from CCRM pin 5 to PCM pin 8, and the tan/lt green wire from CCRM pin 18 to PCM pin 22.

Of those 4 wires that connect to the PCM, all are getting 12v at the PCM harness except the pink/black wire that I believe controls the fuel pump monitor (according to my wiring diagram). The post that ProjectSHO linked says the pink/black wire is FP power. Should this wire be supplying 12v to the PCM? If so, do I need to replace the wire, or does it indicate a problem elsewhere?

Also, when I turn the ignition ON, the CEL does not light up.

 

[frcoonhounds]

PCM question

This post is in relation to my post CCRM? on the engine driveline forum, http://www.shoforum.com/showthread.php?t=116146

My question here is regarding the PCM, specifically Pin 8 on the PCM, which connects to pin 5 on the CCRM. This wire is the pink/black wire from the fuel pump relay to the PCM. When tested with a multimeter, I am not reading any voltage at the PCM wiring harness. All other wires from the CCRM to the PCM supply 12v to their respective pins.

Should I be getting 12v on PCM pin 8, and if so, would the lack of voltage lead to my fuel pump not priming when the ignition is turned on?

I have very little experience troubleshooting and fixing electrical problems. I consulted the ICRM/CCRM sticky for information regarding the wiring. Any help is appreciated to get my SHO back on the road.

Jason

 

[stevoboyd]

idk what the voltage should be. but a better test for checking it would be to use a test light. a multimeter doesnt use enough curent to reliable test the wires for volts.

 

[frcoonhounds]

I'm pretty sure that the correct way to test for volts is to attach the black lead to a ground, probe the wire with red, and the car battery connected. In the volt setting it gives an exact readout of volts. As far as I know, at least.

 

[Green93ATX]

One thought. I am having electrical problems too and one thing I did to help diagnose the problem is to take out the PCM and inspect it to see if I say any burned components.

Its pretty easy - drop the glove box door down to access the PCM. There are two rubber bumpers - one on each side of the glove box. Pinch them in and the box drops down. One little plastic bracket in plain sight and one bolt on face of large connector on the firewall side. The hardest part was getting the PCM out was that the black rubber gasket on the firewall was pretty much glued to the grey plastic connector on the PCM.

A little silicone spray and gentle prying with a very small screwdriver and the gasket finally let go.

There are 6 small screws that hold the cover on. Mine looked great - inspected with a magnifying glass and light. Replaced the PCM and sure enough, it is good. At least I have a spare now. Quite often a printed circuit board like this will have a visably burned component when it goes bad - not always though.

Good luck and I will be interested to know what you find out about this.

 

[frcoonhounds]

I'll take a look at the PCM tomorrow. I have already removed it from the glove box, and all the pins appear to be good on the outside, but I'll make sure to inspect further on the inside of the unit.

Couldn't quite tell if the unit is a stock one, or a d4u1, but I believe it is remanufactured. I'll let you guys know when I open her up.

Still wondering if I should be getting 12v at pin 8 though.

 

[projectSHO89]

Pin 8 of the PCM is an INPUT, not an output. The PCM needs to know when the CCRM is supplying power to the fuel pump circuit.

Go back the CCRM and find out why it is not energizing pin 5.

Please do not start new threads for a continuing issue. Keep everything in one place. Threads merged.

 

[frcoonhounds]

Okay. Took the cover off the PCM and it's an HZ3 model. Failed to notice any signs of damage to the circuit board.

Tested the pink/black wire from pin 5 CCRM to pin 8 PCM for continuity, and the Ohms where very high, resting around 130. I am going to inspect the wire to see if it has corroded somewhere.

 

[frcoonhounds]

UPDATE: After reconnecting the PCM and CCRM, turned the car on and fuel pump primed. After turning the car off and back to on again, no fp.

Checked fuses and noticed that the fuse in the acc feed slot was a 15 amp fuse instead of 10 amp fuse. Also noticed the fuse had some discoloration on the prongs. Swapped in a 10 amp fuse and the SHO fired right up!

The car is running a million times better thanks to new plugs, wires, and the valve cover gasket. I feel like a dummy since the problem was exactly where i started looking, but I guess we all have a few moments like that.

Thanks for all the help. I appreciate your patience and time in helping me.

Jason

 

[SHOMON]

Unplug Your coolant bottle sensor. Replace 10 amp mini fuse in under hood fuse box. I the had the same symptoms as yours on my 95 atx. I replaced the CCRM thinking it was the problem. It was the sensor on the overflow bottle popping the fuse. I think it is marked ign.

Glad it was just a fuse.

 

[frcoonhounds]

Finally started to drive the car regularly the other day. As I was driving home from work, the engine just died cruising on the highway. I popped the hood, checked the 10 amp fuse, and the car started back up. Yesterday, the car died again, except the starter quickly had less and less cranking power. It was clicking rapidly when I got the car towed home, and now it doesn't even crank.

The CEL intermittently would come on and off, but the car scans a 111 code when checked. I am going to disconnect the battery and see if this changes anything.

Does this sound like a Crankshaft position sensor? I also have the problem with the tach working on and off, and the occasional hard start issue.

 

[gmail]

i noticed you said the starter sounded weak...

check all the cables going from battery to the starter to the distro fuse box under the hood . replace the cables with known good ones or brand new ones... clean all grounds related and power connection surfaces.. i bet this will cure your problems.

i had something like this before and this was all it was... if you buy new ones replace the power wire going to the fuse box under the hood with a larger wire... the factory undersizes this hence why when you turn on a bunch of stuff the lights will dim...

think of it like a garden hose.. you can only push so much threw a small hose and in turn you will get pressure.. but if you make the hose larger it will flow more volume and less pressure and not shoot out as far..
only so much you can push threw it before it has to work harder and use up more power threw heat transfer. yet if you use a larger size it will allow more current to pass threw with less draw