SL/R230: 05 SL500 no start
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05 SL500
05 SL500 no start
Hello everyone, I am new to the forum. I have had some bad luck here lately, hoping someone can help.
So, New Years I bought an 05 SL500 red battery light was in the dash, seller told its been sitting for a while it will go away after its driven a while,on the way home stopped to get something to drink,
I had to jump start it to get it home and its been in my garage since. I have replaced the consumer battery,starter fuse under passenger floorboard, starter relay in front SAM, alternator, and starter.
Still nothing. This is my first true MB so if you have any suggestions, or tips it would be greatly appreciated. One more thing. I am only reading 9.8 volts coming out of front SAM.
So, New Years I bought an 05 SL500 red battery light was in the dash, seller told its been sitting for a while it will go away after its driven a while,on the way home stopped to get something to drink,
I had to jump start it to get it home and its been in my garage since. I have replaced the consumer battery,starter fuse under passenger floorboard, starter relay in front SAM, alternator, and starter.
Still nothing. This is my first true MB so if you have any suggestions, or tips it would be greatly appreciated. One more thing. I am only reading 9.8 volts coming out of front SAM.
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From: North Carolina, USA
2004 SL500AMG, 2003 SL500 USA
What do you mean by nothing? Will it turn over, fire, etc.
I put a bosch battery in a Porsche that I rarely started, and it went bad. They are designed to be sent through charge and discharge cycles. I charged both batteries periodically on my project car. Now I am just charging the consumer battery pretty often, when I don't run it and use some juice.
I put a bosch battery in a Porsche that I rarely started, and it went bad. They are designed to be sent through charge and discharge cycles. I charged both batteries periodically on my project car. Now I am just charging the consumer battery pretty often, when I don't run it and use some juice.
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05 SL500
Thanks for your reply
Everything comes on as normal, but the starter does not engage. I ordered a boshe alternator yesterday, original part. The one I bought from Orielies seems to have a draw. I noticed last night even with a trickle charge hooked up the battery was losing voltage, and to beat that the convertable light was flashing so I checked rear battery, 5.5 volts. It was over 12 last night. I am a fair mechanic, but this one has me stumped. Do you have any advice? I would really appreciate it.
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Joined: May 2020
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From: North Carolina, USA
2004 SL500AMG, 2003 SL500 USA
I think the no crank noise is your first issue to overcome. I don't know how to troubleshoot that. I would buy a cheap CPS (Crankshaft Position Sensor) from ebay. You will need a reverse torx/female deep socket, 1/4" drive, maybe 5or6 mm.
I would install new spark plugs.
The front battery is the starter battery. The batteries plus guy said it needs to show more than 12 volts before you start the car. 13 volts is OK. I found a great deal years ago at Walmart online on a Stanley 15 amp re-chargeit that indicates FLO when a battery is fully charged. U can check the voltage any time. If the rear accessory battery shows less than 12 volts, it can impact numerous functions... maybe starting. Of course you must clean/polish the battery terminals with a wire battery brush.
I would install new spark plugs.
The front battery is the starter battery. The batteries plus guy said it needs to show more than 12 volts before you start the car. 13 volts is OK. I found a great deal years ago at Walmart online on a Stanley 15 amp re-chargeit that indicates FLO when a battery is fully charged. U can check the voltage any time. If the rear accessory battery shows less than 12 volts, it can impact numerous functions... maybe starting. Of course you must clean/polish the battery terminals with a wire battery brush.
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From: Gretna, NE
'03 SL55 Black, '03 SL500's Aegean, Mars Red, Tazanite, Alabaster, '11 S550 Flint Gray
I would start by checking drive authorization at the ECU. If you are getting drive authorization, check at starter relay socket. One side of the coil should have 12V with the key on, the other should ground when you attempt to start. If you are missing either, the relay will not actuate and the starter will not engage. Ground is provided by the ECU, so if you are missing that, it is either a wiring issue or a bad ECU.
If you have 12V and ground, relay should be clicking when you try to start. If that is happening, you probably have a bad starter solenoid, bad starter, or wiring issue.
If you have 12V and ground, relay should be clicking when you try to start. If that is happening, you probably have a bad starter solenoid, bad starter, or wiring issue.
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05 SL500
Thank you for the advise. Recently I sent it to a shop that says they are certified to work on MB. They kept my car for nearly a month, I am not sure what, or how they got it started but he said the way they found it was the alternator was bypassing it. I am not sure if your supposed to use these old methods of testing on these cars. Anyway, on my way home from the shop something gave way while I was on the interstate, sounded like a blown tire but it was still driving smooth with no alarms. When I got it home I found the new alternator pulley almost came off. I exchanged for another now I am back to square one. Everything seems normal, the starter just does not engage. I am going with the OEM Boshe, it will be here on Thursday. I will let you know how that goes, I am also going to try the tests you mentioned, I am curious because I can have 12.5V at starter battery, and only 9.5V leaving the SAM, as you know the starter relay is on that same board.
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From: Melbourne, Australia
2005 SL 500 R230
You really need a specialist who knows the R230 to work on it. It is so specialised. So many stories here about 'experts' botching jobs.
Unlikely that the alternator is causing your no-crank issue. Most alternator issues are caused by the regulator in the alternator anyway.
Have you taken out the starter relay (green one on the RHS fuse box) and shorted the contacts? Or take the cover off the relay and pushed the armature? The engine should crank.
That relay has a reputation for failing, with arced contacts. I would at least take it apart and inspect it.
Unlikely that the alternator is causing your no-crank issue. Most alternator issues are caused by the regulator in the alternator anyway.
Have you taken out the starter relay (green one on the RHS fuse box) and shorted the contacts? Or take the cover off the relay and pushed the armature? The engine should crank.
That relay has a reputation for failing, with arced contacts. I would at least take it apart and inspect it.
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05 SL500
I have tried different relays, same thing. I haven't tried taking one apart to check it, I am concerned about the voltage coming from the SAM itself. I'm only getting 5.5v where it should be showing 12v.
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From: Melbourne, Australia
2005 SL 500 R230
You have 12V at pin 85 on the starter relay with the ignition on, or 5.5V?
Have you tested the starter circuit by bridging 30 and 87?
That's a quick way to rule out the starter solenoid and motor.
Have you tested the starter circuit by bridging 30 and 87?
That's a quick way to rule out the starter solenoid and motor.
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From: Gretna, NE
'03 SL55 Black, '03 SL500's Aegean, Mars Red, Tazanite, Alabaster, '11 S550 Flint Gray
Responding to this thread instead of the 2nd one you started. What is the rear battery voltage? Despite being 3" away from the starter battery, the front passenger SAM (all three SAMs) are powered by the rear battery. When you say 5.5V leaving the SAM, what circuit are you referring to?
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From: Melbourne, Australia
2005 SL 500 R230
I haven't tried bridging yet. Are you suggesting a wire or something at the 2 contacts?
Yes, but that is just to test the starter circuit, but it sounds like you're not getting the relay to engage. So, do the tests mentioned earlier.
Easiest way to check the starter and solenoid is to clip the cover off the relay and (with the ignition off) push down on the armature which will engage the starter solenoid, then the starter motor. If she cranks vigorously then the starter is fine.
Yes, but that is just to test the starter circuit, but it sounds like you're not getting the relay to engage. So, do the tests mentioned earlier.
Easiest way to check the starter and solenoid is to clip the cover off the relay and (with the ignition off) push down on the armature which will engage the starter solenoid, then the starter motor. If she cranks vigorously then the starter is fine.
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05 SL500
Thanks I will definitely try taking the relay apart to test it. I tried the sockets but my meter probes go not make contact through the slots.
I did not know the front SAM was powered by the rear battery, that really helps.
The rear battery was at 12.3v the last time I tried to start it. I keep the batteries unplugged, and on charge until I get a chance to work on it.
What I mean by coming out of the SAM is there is a power cable that clips down in the front of it then another plug that leaves the rear, thats where I have been checking voltage.
I did not know the front SAM was powered by the rear battery, that really helps.
The rear battery was at 12.3v the last time I tried to start it. I keep the batteries unplugged, and on charge until I get a chance to work on it.
What I mean by coming out of the SAM is there is a power cable that clips down in the front of it then another plug that leaves the rear, thats where I have been checking voltage.
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05 SL500
So last night I took the relay apart and plugged it back in. Turned the key over to the second position and worked the armarture manually. it seems like the starter circuit is dead. I have noticed thar there is no spark at all when I attach the negative terminal. I'm guessing bad connection from starter, or something like that. I went ahead and removed all the covers underneath.Looks like its going to be fun. I have not looked at any videos yet, but can anyone tell me right off, does the exhaust have to come off to get the starter out? This is a new starter put on by mechanic.
Even better yet... Whene taking the cooling hose loose to get alternator out I lost a little fluid, did'nt think any thing of it.
Turns out it's hydraulic fluid, and I can't find exactly where it's coming from. So I already have my next project lined up.
Thank everyone for your comments and suggestions, it really helps alot!
Even better yet... Whene taking the cooling hose loose to get alternator out I lost a little fluid, did'nt think any thing of it.
Turns out it's hydraulic fluid, and I can't find exactly where it's coming from. So I already have my next project lined up.
Thank everyone for your comments and suggestions, it really helps alot!
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From: Melbourne, Australia
2005 SL 500 R230
Sorry I haven't read back through the thread but is the front battery good and charged up?
Even if pretty flat, you should still hear the solenoid on the starter click.
Before changing the starter, I would test it by shorting the two big copper terminals on the motor, with a thick jumper cable. The starter should crank.
You say it was changed recently. First step: inspect all the connections down there. Maybe the lead to the solenoid 'fell' off?
I've lost count of the number of times I have had to clean up after 'expert' mechanics bodged jobs. It is just woeful and tedious, paying someone for work, and then having to do it yourself again, properly.
Even if pretty flat, you should still hear the solenoid on the starter click.
Before changing the starter, I would test it by shorting the two big copper terminals on the motor, with a thick jumper cable. The starter should crank.
You say it was changed recently. First step: inspect all the connections down there. Maybe the lead to the solenoid 'fell' off?
I've lost count of the number of times I have had to clean up after 'expert' mechanics bodged jobs. It is just woeful and tedious, paying someone for work, and then having to do it yourself again, properly.
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05 SL500
Thanks Manning, I've tried bridging at the relay socket but not the actual starter. I did raise it up enough to get under the car and check voltage, 12.2v
at both starter and solenoid. I know there is a way to bump the starter, just unsure what to bridge. I will try today, the manager of the shop I took it to is coming to my house to confirm. I was a bit upset because they had it for almost a month and still it sits in my garage.
Now I'm wondering if the incline has anything to do with it starting.
at both starter and solenoid. I know there is a way to bump the starter, just unsure what to bridge. I will try today, the manager of the shop I took it to is coming to my house to confirm. I was a bit upset because they had it for almost a month and still it sits in my garage.
Now I'm wondering if the incline has anything to do with it starting.
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From: Melbourne, Australia
2005 SL 500 R230
You're getting 12V at the solenoid when you turn to start? No loose connections?
Then it's sure to be the starter. Even if you can knock it into action, do you want to be stuck with a suspect starter? Best to just replace it as they're available and not too pricey, but I don't know the cost of a genuine.
But it was already replaced, so maybe you can get it under warranty.
Then it's sure to be the starter. Even if you can knock it into action, do you want to be stuck with a suspect starter? Best to just replace it as they're available and not too pricey, but I don't know the cost of a genuine.
But it was already replaced, so maybe you can get it under warranty.
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05 SL500
The manager from the shop came by my house with scanner/diagnostic tool.
there was several functions that were turned off, including starter, and EIS. Soon as I seen the ignition switch I knew it was a Mercedes issue. Sitting too long with no power, im not sure? It looks like the car needs to be reprogrammed.
there was several functions that were turned off, including starter, and EIS. Soon as I seen the ignition switch I knew it was a Mercedes issue. Sitting too long with no power, im not sure? It looks like the car needs to be reprogrammed.
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05 SL500
Thanks, that question made me think, but I think your right. The diagnostic tool showed it was off, it wasn't the SDS but very similar. It didn't have the capability of turning the issues back on though.
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From: Gretna, NE
'03 SL55 Black, '03 SL500's Aegean, Mars Red, Tazanite, Alabaster, '11 S550 Flint Gray
There is no turning modules on or off. They either have power or they don't. If the key turns, your EIS is either broken (unlikely), or it has power and is recognizing the key. If you have any circuit 15 power (with key on), the EIS has power and is at least partially functional. If anything turns on, lights up, beeps, etc. when you turn the key on, you have circuit 15 power.
All Mercedes vehicles of this era have multiple connections for diagnostics. It is possible that you have a pin pushed back in the diagnostic port or some other issue reading some lines. Some modules have direct connections with the diagnostic port, other have indirect communication via CAN through another module, so CAN communication is also important. The EIS does fail and it is possible that yours is bad, but with your description of the problem, I think you have something else going on.
All Mercedes vehicles of this era have multiple connections for diagnostics. It is possible that you have a pin pushed back in the diagnostic port or some other issue reading some lines. Some modules have direct connections with the diagnostic port, other have indirect communication via CAN through another module, so CAN communication is also important. The EIS does fail and it is possible that yours is bad, but with your description of the problem, I think you have something else going on.
