How do I tell if the CCRM is bad? (Intermittent starting problem)

[bleavitt23]

Hey guys,
I have been having a problem with starting the SHO lately. It is a 93 MTX. 2-days ago I was about to go to work when it wouldn't start. This made 3 times this has happened in the last couple of weeks. The first time, it wouldn't start in the morning but when I got home from work it started up just fine. Same with the second time this happened. This last time it wouldn't start for 2 days and when I went out this morning to try my luck it worked just fine. Now, When this happens I have noticed that the fuel pump isn't priming. So I tested the power wires to the pump and found that last night when it still would not start there was no power going to the pump and this morning, when it would start, there was power. Also, upon a KOEO code scan I got a few trouble codes. I got a 157, 524, 542, 543, and the ones I was most concerned about, a 556 (Fuel pump relay primary circuit failure), and a 557 (Low speed fuel pump primary circuit failure). So, is all of this indicating a bad CCRM or might it be something else? If it is the CCRM does anyone have one with the letter code "M" that I could buy off 'em? I welcome any and all input that anyone can give.

Thanks Much,
B

 

[SHOZ123]

You can force the FP on to test it. On the DATA link connector where you check for codes, hold it with the longest side down. Using a jumper and with the key on, ground the right most connector.

If the FP does not come on there is no power going to the FP and the FP relay in the CCRM may be bad. (likely the case)

To see if the CCRM FP relay is good, with the FP DATA link pin shorted check the Pink/Black wire coming from the CCRM for 12V+. This wire is the power feed to the FP.

If there is now power on the PK/BK wire then see if there is 12V+ on the Violet or the Black/Orange wire on the CCRM. If either of these has 12V+ and the PK/BK wire does not then the relay in the CCRM is bad.