Engine/Transmission (1998.5 - 2002) caTCHER ecm (Marco's aka MAD)

[Murle]

I have a question. I'm thinking on leaving my original ecm in its place and just putting the MAD ecm just close where I can plug it in. Was wondering if anyone knows if the ECM needs to be grounded????

 

[Gary - K7GLD]

I have a question. I'm thinking on leaving my original ecm in its place and just putting the MAD ecm just close where I can plug it in.



Sort of a case of wearing both a belt AND suspenders, eh?

 

[Murle]

Well If you must know I DO wear both belt and suspenders.

 

[Gary - K7GLD]

*I* can't laugh TOO hard - I'm almost there myself!

 

[Casey Ray]

Originally posted by Murle

I have a question. I'm thinking on leaving my original ecm in its place and just putting the MAD ecm just close where I can plug it in. Was wondering if anyone knows if the ECM needs to be grounded????

According to the service manual under ECM installation:



Do not apply paint to the back of ECM. Poor ground will result.



(1) Clean ECM mounting points at engine block.



(2) Position ECM to engine block and install 3 mounting bolts. Tighten bolts to 24 N*m (18 ft. lbs).



(3) Check pin connectors in ECM and 50-way connector for corrosion or damage. Repair as necessary.



(4) Cleans pin in 50-way electrical connector with a quick-dry electrical contact cleaner.



(5) Very carefully install 50-way connector to ECM. Tighten connector hex bolt.



(6) Install battery cables.



(7) Turn key to ON position. Without starting engine, slowly press throttle pedal to floor and then slowly release. This step must be done (one time) to ensure accelerator pedal position sensor calibration has been learnd by ECM. If not done, possible DTC's may be set.



(8) Use DRB scan tool to erase any stored companion DTC's from PCM.



end quote.





Yes the ECM does need grounding.



cul,



Casey

 

[darkhorse]

I was wondering the same thing, since it was mentioned by another member a few days ago. My Factory service manuel states "Do not apply paint to the back of ECM. Poor ground will result. " It also states to clean the mounting points at the engine block. I therefor presume it needs to be grounded to the block.

 

[Bob Wagner]

AND DONT PANIC you will get a check engine light first time its fired up its the generic P1693 code that clears right up.

 

[darkhorse]

I appreciate the "heads up" on that one, Bob.

 

[Gary - K7GLD]

ECM needs to be grounded eh?



Seeing many other poor accomodations for decent grounding right outta the factory, I think next time I'm under the truck, I'll take the multi-meter with me to see exactly how well it IS grounded - and probably run a dedicated separate ground right to the battery...

 

[Marco]

No ground!

The ECM needs NO GROUND through it's case!

All the signals voltages and the grounds are supplied to it through

the 50 way connector.



My ECM has had no ground to it's case in the last 4 years... .



'Nough said???



Marco

 

[amillstream]

Got mine yesterday!!Oo. Oo. Oo. Going in tonight after work. Would have put it on last night but had a date and figured it could wait just one day anyway. Any body else got theirs?

 

[Gary - K7GLD]

The ECM needs NO GROUND through it's case!

All the signals voltages and the grounds are supplied to it through

the 50 way connector.



Thanks Marco - saved me some extra work!

 

[Chipstien]

Can't wait to here the reports. Oo.

 

[darkhorse]

My MAD CaTCHER

I am happy to report that UPS delivered the magic box today. It's amazing how difficult it is to get at those three little bolts that hold a ECM to the block. I got my forearms scraped up some but it went in. I set the throttle per the factory service manual & fired her up. The idle was rough & the tach jumped around a couple hundred rpm. The vp was much louder & sort of knocked. I took the truck out for a 25 mile test spin. The power is awesome. It comes on very fast at low rpm. Rolling the power on carefully I was able to get much quicker starts with out smoke than I did with the EZ. A little to heavy & the smoke was thick & black. Much more than 1/2 or 2/3 throttle & my stock clutch would start to slip. Backing off a little stops the slip but she will continue to rev right out to 3200 in a flash. I'm not running a boost elbow right now but I still saw about 25 psi. The egt's were the same as always, that is no more than 1000*



The power curve is really steep but it doesn't seem to be smooth. I experienced at least a couple of strong surges. What with all this incredible power I almost forgot how rough it started out idling. I was reminded when I stopped charging up hills turned around & headed back down hill toward home. Some of that roughness & noise was apparent at light throttle settings.



A couple of other odd things didn't work right either. The "wait to start" light never came on & the cruse control wouldn't function at all.



Sitting back in the drive with the motor idling rough & the vp clacking I'm puzzled. I tried tightening the allen on the connector plug with no effect.



I put the original ECM back in & the truck ran as smooth as ever.



There's got to be something wrong here. I'm hoping it's as simple as a bad connection on the plug. I've got some spray cleaner for TV tuners I'll try clean things up with.



It will probably be Sunday before I'll be able to get it back in for another try.

 

[SmokinJoe]

Originally posted by Chipstien

Can't wait to here the reports. Oo.

As soon as I can afford it I will be buying one as well.

 

[Bob Wagner]

the 1700 rpm really rocks

 

[Chipstien]

Not the best post for first impression. However it definately sounds like something isn't right.

 

[jcbrown]

Cruise Control...

Originally posted by darkhorse

A couple of other odd things didn't work right either. The "wait to start" light never came on & the cruse control wouldn't function at all.

Does your truck have ECM Electronic Cruise Control?

 

[darkhorse]

Yes, my truck has the electronic cruise control.

 

[smittybuilt]

as soon as some of the guys selling this thing gets some built up so you can just do a swap out like injectors i am ready to buy!