SL/R129: 1990 500SL CPS (crank pos. sensor)
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1990 sl500
1990 500SL CPS (crank pos. sensor)
My diagnostic reader is throwing the crank position sensor code. Is there anything else besides a bad sensor that would throw this code? The car cranks but it wont start, and acts like it is out of time when it does fire, and wont stay running. Anyone else had to change this sensor? Are there any videos?
To add, it was misfiring, and had no acceleration when I parked it. Finally got around to working on it and it wouldnt start at all.
To add, it was misfiring, and had no acceleration when I parked it. Finally got around to working on it and it wouldnt start at all.
Last edited by jfmiller003; Oct 8, 2016 at 05:31 PM.
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From: Atlanta, unfortunately
'09 S600, (2) R129 300SLs, '03 SL500, '03 SL55
This code is meaningless unless you retrieved at while the engine is running -- Catch-22?
Here is the diagnostic manual for your ignition system: http://manual.startekinfo.com/manual..._1/content.jsp.
Here is the diagnostic manual for your ignition system: http://manual.startekinfo.com/manual..._1/content.jsp.
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Joined: Jan 2015
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From: Worcestershire UK
W124 260E
Take your tester and throw it in a river---then buy a new one and if you get the same code throw that in the river,but retrieve your old tester and buy a new CPS because the tester you threw in the river was correct.
PS: An additional confirmation would be your wife girlfriend or what ever!!
PS: An additional confirmation would be your wife girlfriend or what ever!!
Thread Starter
Newbie
Joined: Mar 2015
Posts: 5
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1990 sl500
This code is meaningless unless you retrieved at while the engine is running -- Catch-22?
Here is the diagnostic manual for your ignition system: http://manual.startekinfo.com/manual..._1/content.jsp.
Here is the diagnostic manual for your ignition system: http://manual.startekinfo.com/manual..._1/content.jsp.
I thought the computer stored codes from a running engine? Im not trying to be a smatass, just trying to get this solved.
Thread Starter
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1990 sl500
Banned
Joined: Jan 2006
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From: Atlanta, unfortunately
'09 S600, (2) R129 300SLs, '03 SL500, '03 SL55
You are correct, and that is the Catch-22: to set a code for a faulty CPS the engine must be running; but if the CPS is faulty, the engine probably is not running.
If the engine is not running you will always read a code for a faulty CPS, and therefore it tells you nothing about the condition of the CPS and is meaningless.
Also, observing the tachometer while the engine cranks reveals nothing, since the RPMs are much too low to register.
If the engine is not running you will always read a code for a faulty CPS, and therefore it tells you nothing about the condition of the CPS and is meaningless.
Also, observing the tachometer while the engine cranks reveals nothing, since the RPMs are much too low to register.
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From: Worcestershire UK
W124 260E
JF i dont know what it could be other than if the taco flickers CPS is not the problem .Check all the fuses are clean and makeing contact .You need to find if its fuel related ,or electrical. Have you got a spark at the plug , ?.and is it getting fuel? This is what you have to find out . Pull a plug see if its wet,= fuel is there , if the plug is dry your getting no fuel. If wet remove all the plugs to dry them off .Refit when they are dry.The wet plug will tell you its electrical . Remove one plug wire , and fit in a known good spark plug, hold close to the engine ,spin it over .No sprk = electrical problem .
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