Crank, no start

2003 MERCEDES BENZ C320
143,000 MILES • 3.2L • V6 • AUTOMATIC
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BETH GAUTHREAUX
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Engine threw a rod, replaced engine with another 3.2l v6. The car will crank but will not start. At first it would not do anything, just click. So we changed the starter. Now it will crank but nothing else. We changed the crank position sensor, tested all wires going to the ECU and are getting correct voltage. I'm getting no spark and no fuel from the fuel injectors. Good fuel pressure in the fuel rail. Battery is good.

Could the computer be bad? I am not getting any of the other symptoms of a bad computer.
Mar 26, 2017 at 6:10 PM
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STEVE W.
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How close is the replacement engine year wise? Some of the companies made a lot of changes in that era and entire engine control systems and engine hard parts were different. The engines would bolt in and appear normal but because of the changes they won't ever run.

Another possibility is that the battery disconnect may have triggered the built in security system and tripped the immobilizer which shuts off fuel and spark. On some of them you can reset that yourself.
https://www.2carpros.com/articles/how-to-reset-a-security-system
On others you need a good scan tool to do the reset.

The only other item may be that you have to do a reset on the ECM so it can see the new crank sensor.
Mar 27, 2017 at 7:25 AM
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BETH GAUTHREAUX
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It came out of an 01 SLK (which we were told by the company that it would work but I am not holding my breath on that at this point). How would we do an ECU reset? I have tried one of the methods I found on Google about turning the key to position 2, holding foot on accelerator, etc., but that didn't seem to work. I will try the security system reset though and go from there. Thank you!
Mar 27, 2017 at 12:21 PM
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STEVE W.
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For most of them you do the reset for the sensors with a good scan tool, not the code readers that they use to scan for free. I actually try to avoid BMW and Mercedes because they don't really use a uniform diagnostic from year to year or even model to model. They also seem to think that if having one wire and a solenoid to do the job is good, replacing that with two control modules that you need to use a scan tool to access is just right...

OK it's a 2003 C320 Coupe, Sedan, Wagon? With All Wheel or only rear wheel drive?
Those are different going by Hollander. At least it may point out that you have a "correct" engine.
Mar 27, 2017 at 4:49 PM
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BETH GAUTHREAUX
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It's a sedan. Rear wheel drive. And being that it didn't give me the specific model of the slk, I don't know any info regarding the donor engine.
Mar 27, 2017 at 5:32 PM
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BETH GAUTHREAUX
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They also asked for the VIN number to make sure it would work before they shipped it out.
Mar 27, 2017 at 5:34 PM
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STEVE W.
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OK, they show the SLK 320 as using the same engine, so it should be correct.

I doubt the ECM is bad. It sounds more like a security issue. Might be worth it to get it to a dealer and have them do a full scan and make sure the ECM is OK and they can look at the system and see if it is a security issue.
Mar 27, 2017 at 5:49 PM
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BETH GAUTHREAUX
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ok. Thank you!
Mar 27, 2017 at 6:22 PM