This is the secound time the ignition control unit EZL gets damaged on my 560SEL 1989. It's Euro specs and replacing it is so costy. The first time I replaced it with a new Bosch coil (the original green sticker) and new Beru ignition wire set, then after arround 3 months the EZL unit got damaged again. I wounder what are the main reasons that could damaged the most expensive part after the engine and transmission.

I Always use the original parts and the car is in a good condition. I use the best unleaded gasoline and change the oil periodically every 2000KM with Titan 15-40.

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Master Computer Engineer, A+, Network+, MCP/MCSA/MCSE 4/2k/2k3 - Messaging, MCTS, MCITP, MCT, Brainbench, ICDL and starting Ph.D

380SE 1984 <------- Totaled by flipping accident
300SE 1988 <------- Sold
Volvo S70 2000 <---- 4 family
Opel Omega 2002 <-- 4 family
560SEC 1989 <------ Sold
560SEL 1990 <------ Sold
560SEL 1991 <------ 4 my mother
560SEL 1989 <------ Sold
600SEL 1992 <------ Current

http://search.ebay.com/_W0QQsassZkhazenzcc

since the original part lasted a long time & that one failed quickly, that is a good question!

ONLY time I was able to verify the cause of failure on those units was alter someone left the key on for HOURS..killed both EZL & coil!!

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MERCEDES Benz Master Guild Technician (6 TIMES)
ASE Master Technician
Mercedes Benz Star Technician (2 times)
44 years foreign automotive repair
27 Years M.B. Shop foreman (dealer)
MB technical information Specialist (15 years)
190E 2.3 16V ITS SCCA race car (sold)
1986 190E 2.3 16V 2.5 (sold)
Retired Moderator

Charging or jump starting the car with the ignition on, voltage spikes from an over charging alternator, bad ground wires , your over volt protection relay should protect against that type of failure, defective relay. Static electricity, you should alway discharge your self when install , removing any ECU. Any Welding done to the car lately, that would fry any controller if not disconnected from the car.

Did the replacement have the paste and the plastic on the back?

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Chuck Taylor
Falls Church VA
'66 200, '66 230SL, '96 SL500. Sold: '81 380SL, '86 300E, '72 250C, '95 C220, 3 '84 280SL's '90 420SEL, '72 280SE, '73 280C, '78 280SE, '70 280SL, '77 450SL, '85 380SL, '87 560SL, '85 380SL, '72 350SL, '96 S500 Coupe

2 most likely causes are:
1) Excessive heat due to poor heat conductivity--low air flow, no heat transfer paste,etc
2) Low system voltage--leading to excessive current draw and excessive heat generation in the EZL
3) Loose/poor ground connections causing voltage spikes

Why do you have to use 'european' EZL--the american one will have less timing advance,lower RPM limit?. Won't it work just fine?

The EZL unit has the paste and the plastic on the back. And I'll never plane to use the American EZL because it's less powerful then the Euro one. My 560SEC has the 4x4 pins one but it sucks.

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Master Computer Engineer, A+, Network+, MCP/MCSA/MCSE 4/2k/2k3 - Messaging, MCTS, MCITP, MCT, Brainbench, ICDL and starting Ph.D

380SE 1984 <------- Totaled by flipping accident
300SE 1988 <------- Sold
Volvo S70 2000 <---- 4 family
Opel Omega 2002 <-- 4 family
560SEC 1989 <------ Sold
560SEL 1990 <------ Sold
560SEL 1991 <------ 4 my mother
560SEL 1989 <------ Sold
600SEL 1992 <------ Current

http://search.ebay.com/_W0QQsassZkhazenzcc

Where is this EZL located? Apparently I need one for my M116 to M117 swap...

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I'm not a doctor, but I'll have a look.

'85 300SD 245k
'87 300SDL 251k
'90 300SEL 326k

Six others from BMW, GM, and Ford.

Liberty will not descend to a people; a people must raise themselves to liberty.[/IMG]