'01 CL600 had one good day (60 miles) after replacing Crankshaft Sensor and Harness, and both Camshaft Sensors and their Harnesses. Prior that it had a no-start issue, and all three of those sensors were throwing codes. Now I have to start and restart the car 2-3 times to get it out of Limp Mode. Once out of Limp Mode, it runs great. Fabulous, even. So ... what am I experiencing? Do I just need to put more miles on it and let the machine self-learn? Are the sensors I put in not exactly what the car wants/needs?

I disconnected/reconnected the battery to see if that helped. That set off a slew of codes that eventually cleared (ESP, BAS, ABS...). After this last test drive I'm down to only the right Camshaft sensor showing an error.

Another interesting thing ... if I do not erase the code(s), everything runs fine. If I erase the code(s), it takes several restarts to get it out of Limp Mode.

Any experiences with this will be appreciated.

 

The camshaft position sensor may be the problem at all time to put the cat into Limp
home mode. What are the trouble codes saying? Do you have any trouble code numbers to post here? There is a big difference between a camshaft electric circuit problem and a camshaft range performance. If the trouble code is saying range performance, there might be a problem with the alignment of the timing and probably a chain/belt problem.
If there is a circuit problem, check if you got the correct voltage to the crankshaft and camshaft sensors.

 

Good info/questions. I'll run another diagnostic, shortly. A mobile tech I had look at it, months ago, said it was an electric circuit issue related to the Camshaft. That's what led me to replace the harnesses (Camshafts and Crankshaft) and all the relays. If that hadn't worked, I was going to start pulling apart the wiring looms and looks for shorts/rewire all the way from the harness to the fuse box.

Its been running great. Will post read outs later today.

 

More intrigue. Less Codes.
Bottom line: I have no more engine codes. No CEL. Nothing pending. All clear.
Ran a full scan with my Foxwell NT520 Pro as I got into the car, this afternoon. Saw 5 pending codes. Both Camshaft sensors and three codes related to O2 sensors. Drove 20 minutes. Stopped. Erased all codes. Shopped for 20 minutes. Came out and ran another full scan. All codes had cleared. Checked with my discount store (Harbor Freight) scanner, and it confirmed their were no codes of any kind, not even pending.
My guess is that my 2001 W215 CL600 needed a long relearning cycle. I had not run (much) in 3-4 years. It needed almost 150 miles and 20+ restart cycles to reach a fully functional state. In my tenure its gotten new camshaft sensors, a new crankshaft position sensor, the wiring harnesses to those three sensors, and a new starter. Plus, I replaced all the relays (14?) in the engine fuse box.
Whatever the reason, tonight I go to bed with a fine running car in my garage. For that, I am happy.
FYI: Visited my county tax office today and got the CL600 titled and registered. The 2018 taxable value for this fine automobile; $1845. The sticker price on the showroom floor in 2001: $140,000.