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Hi
My Benz C-Class C240
Year 2002
Won't Crank and Start so I checked all the fuses and relays no blown fuses and relays
But I found there is no power on fuse #52 (start enable) 20A fuse located under the hood
Please assist me to solve the problem?
What is next step?
Thank you
In the crank position is Fuse 52 hot?
In the crank position are any of the fuses #48, #47,#49 or #46, hot?
Do your wipers work? (fed from fuse #46)
Here is fuses listed
Fuse 52 is Start Enable (no current in positive side pin)
Fuse 48 is Engine Electronics (working have current)
Fuse 47 (working have current)
Fuse 49 (working have current)
Fuse 46 is windscreen wiper it has current but viper is not working
And no fuses are hot
Fuse 58 (transmission electronic) also have no current in positive side pin
*when key is on fan start running
Forgive my poor choice of the word "hot." I should have wrote, do you have power at both sides of the fuse.
Your result that all those fuses have current (Did you mean power? If you measured current that's fine, you can't have current flow without power) suggests to me that the Circuit Opening Relay has control and the relay is functional.
jreardon wrote: Forgive my poor choice of the word "hot." I should have wrote, do you have power at both sides of the fuse.
Your result that all those fuses have current (Did you mean power? If you measured current that's fine, you can't have current flow without power) suggests to me that the Circuit Opening Relay has control and the relay is functional.
Yes I mean power
But Fuse 52 and 58 had no power on any side and all the other fuses have power on both side , All the relays are checked and working
You swapped the fuse or starter relay? Fuse 52 won't have power on either side because the starter relay coil is not being energized by the SAM module (whatever that is). Either that, or the relay is defective.
If you pull the starter relay, there are 4 female terminals (?). Two goes to the SAM module so I'm not sure what voltage, if any, to read on those two. The two others , well, one one them should be grounded through starter motor. And the last one should have power when fuses 48, 47, 49 get power.
Can you find a diagram etched on the starter relay to indicate the load side pins?
If you jump the correct (very important or you will fry the SAM module) load side female terminals, the starter should spin.
If that is correct picture of your starter relay see if jumping terminal 3 and 5 will make starter spin. Strange how the SAM module will energize control coil for the Circuit Opening Relay, but not for the Starter Relay, hmmm. If pin 5 was the one you found as ground terminal, jump straight battery power to it.
jreardon wrote: Is this what starter relay looks like?
Yeah same 4 terminal relay have
And Positive side is working
(Previously one is mistakenly said ground terminal is working)
So no ground is in starter relay
jreardon wrote: If that is correct picture of your starter relay see if jumping terminal 3 and 5 will make starter spin. Strange how the SAM module will energize control coil for the Circuit Opening Relay, but not for the Starter Relay, hmmm. If pin 5 was the one you found as ground terminal, jump straight battery power to it.
Pin 2 and Pin 5 has positive power
When relay is energized pin connected to pin 3
jreardon wrote: Put your test light in series with Pin 1 and Pin 2. If light does not light in crank position, then, well, let's just say something's not right.
Do you have computer communication with scanner?
Checked pin 1 and pin 2 in series it’s not working
And did scanning too there are only 2 - 3 fault
SRS fault
Transmission fault
There is no fault related to crank or Start
