stargirl

i drive my 2010 ML350 with 49K miles about 100 miles a week. after having an independent mechanic do the C service several weeks ago, my "ABS/ESP inoperative" message and yellow lights came on. back to the shop. his scanner said my left front speed sensor was bad.
the next time i drove it, the display was normal and there were no warning lights.
at the end of june the car went into limp mode but no messages or lights appeared. i shut off the engine and restarted it, everything was OK.
2 days ago i was on I-95 and the warning lights and messages came back on but again, no limp mode. after awhile, the ABS light and the "inoperative" message disappeared but the ESP light was still on. i turned it off by pressing the ESP button.
when i got on I-95 again an hour later, limp mode returned. no lights or messages appeared. i exited, shut off the engine and restarted it. everything was normal---operation and displays.
the mechanic scanned it again and found 2 codes for the left front speed sensor. he put the car up on a jack and spun the left front wheel, the readings were within the normal limits of 0-155.
we ordered the sensor on amazon for $57 but the seller said he doesnt have it in stock, even tho his listing says there are 9 available. grrr
the mechanic said it could also be the wheel bearing, the magnetic strip sometimes causes an error code for the speed sensor.
im puzzled---why is this problem intermittent? and why dont the warning lights/messages coincide with limp mode?
is this car safe to drive? limp mode spooks me.
i miss my 2000 ML430, it didnt have all these super sensitive computers.
thank you for any thoughts on this vexing issue.

2011mbml350

same thing happened to me 2 months ago. mechanic fixed something (he said reprogrammed the computers) i would say drive it. limp mode is not going to apply brakes or anything it will just slow down. but i wouldn't take it on the highway.

stargirl

thanks for your response, 2011mbml350. youd think that if computers need to be reprogrammed, a message saying that would appear---not an error code for a speed sensor. and certainly not unexpected limp mode. but what do i know. did you have your ML scanned?

2011mbml350

yep,had it scanned but didn't bother to check as i was out of province. if its telling you its the speed sensor.then thats gonna be it. try it atleast it isn't that expensive.

stargirl

thanks so much again, 2011mbml350. will post again after the speed sensor is replaced next week.