CCRM (relay module) Reverse Engineering

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Well go here and down to post #18...that's where this all started.

I've researched and found a few documents and threads about the relay module, but nothing comprehensive. It may be out there, but I can't find it.

http://http://www.shoforum.com/showthread.php?t=128464

I opened up my relay module today and have a few initial observations.

- the relays are PCB (printed circuit board) version of standard spade-terminal relays you'd buy at any parts house.

- these PCB-mount relays are not at all easy to find (but I have)

- the circuitry itself inside the module is extremely simple (it's not much beyond the relays besides reverse polarity diodes and a regulator circuit.

- (2) relays are for the fans (lo and hi), and (2) relays are for A/C clutch and fuel pump.

- (2) relays are Omron 12V, 20A, SPST, (2) relays are Bosch 12V, 40A, SPST

- SPST is single pole, single throw

- The part numbers on the relays themselves will not likely get you to a place where you can actually purchase them, but thankfully I have cross-reference material that helps me find what the real part numbers are.

- The relays are available, but not in the US

- In the grand scheme of electronics repairs, there are only (6) parts worth changing in the module...(4) relays and (2) electrolytic capacitors

The documents I downloaded to go off of had some incorrect information actually. The 24-pin connector of the module is incorrect, and the internal diagram was also incorrectly labeled. (1) was made by an individual and the other looked like a factory document.

I'll get all this straightened out, but I'm working from a J-code CCRM in a '94 auto tranny car.

Pictures...










 

SHOdded

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Great pics & info, Chris. Doesn't Omron make BP monitors? Anyway, how repairable do you think these modules are? Can the circuit board be re-created?
 

rubydist

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the circuit board should not need to be created - the typical problems are relays with burned contacts so they don't flow current, and capacitors that have died so the circuit does not function. those can all be unsoldered and replaced.
 

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Omron makes a LOT of things, mostly I am familiar with their PLC stuff and relays of course.

Fred is right, the PCB does not need to be reverse-engineered and remade.

High-failure components like the relays and electrolytic capacitors are all that need to be replaced.

Relays have a contact rating like (10,000 makes) and I'm sure these are well passed that!

And you're welcome by the way!

I'm going to create a schematic just because I want to, and I already found the proper relay part numbers.
 

sperold

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Great information.
This is where the value of this forum becomes apparent.
Thanks for the effort on this topic.
 

decipha

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as you seen its nothing special, I've deleted them on numerous setups for a more simplified install
 

3d914

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Chris,

Thanks for taking the time to dig into this. Here are couple of links for threads I started that have one schematic or another for the CCRM. From my research I know that both (MTX & ATX) are not equally detailed, so we'll definitely benefit from any documenting you do.

My rough schematic for a custom CCRM - not sure its right though

3.0L PAVLIN schematic for CCRM

Good luck.
 

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I'll get to that today possibly...getting prepped for Thanksgiving so we shall see.

Oh, just a bit of information for you, that voltage inverter *relay* isn't a relay at all. It's just as stated...it's a voltage inverter but a circuit that simply has a square drawn around it (for separation I assume). If you count the number of relays on the PCB, you will only count (4).
 

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I received my spare relay module and began digging into it...the first thing I noticed (which I read a lot about) is grounding. I hear a lot about the (2) screws that hold this module in place and can wreak havoc.

There is no physical connection from the circuit board to any part of the metal housing on this thing...from the way people say that crusty screws can cause grounding issues I fully expected a connection.

I have removed both screws and even took the circuit board out of the housing and have driven with it like that for a few days now. No issues.

Just a side note really not meant to start a war. Hehe

I am going to rebuild the spare module and install it, then reset my codes and see if that changes anything (I have a persistent fuel pump relay code).

I'm going to de-solder and test the relays first. The relays are sealed, so getting inside to physically inspect the contacts is not difficult but a challenge still.
 

sperold

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I was really surprised when my car would still start with the CCRM unbolted from the rad support.

Most of the talk of grounding and the importance of grounding screws (on this forum) is related to the DIS module located on the intake connector tube, and it is a real issue when not grounded.
 

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Ok, I've been running the rebuilt module for a few days now (I cleared the codes after swapping).

I'll check the codes tonight to see if that pesky fuel pump code comes back.
 

3d914

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Great news. Can you provide some detail on the inverter part of the circuit, maybe even a schematic.

TIA
 

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My apologies for the delay...I'm still working on this by the way.
 
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