99 C280 Cranks but will not start
 

Hello All,

Checked all the threads I could find on this. I have a 1999 C280 that will sometimes crank over easily but will not start. It's an intermitent problem that just started two days ago.

I saw all the posts on the OVP Relay, but I'm not certain if a 99 has this relay.

I did check under the black cover on the passenger side in the engine compartment and found a SIEMENS relay with a A 002 542 13 19 on it and wonder if this is it.

For those in the know, please tell me if a 99 C280 has an OVP relay, and if so, do I have the right relay? Of course, if you believe there's another cause to this problem, please let me know.

Thanks!

John

I don't think any Mercedes had a OVP since about 1996. Someone please say if I am wrong but I think that is pretty close.

Just as a guess, it could be a fuel pump relay.

There is no OVP on the '99 C280. It sounds like you may have a problem with the crankshaft position sensor (CPS). Does the car start if you let it sit for 30 minutes or so?

Ahh, yes, I missed the intermittent part. Yes CPS is a good guess, especially if it occurs only when it is hot (warmed up). I would think that should throw a code and the CEL but I don't know.

When my CPS went, no code stored, no CEL.

I'd start there.

Yep, it will start if you let it sit a while.

I have a Harbor Freight Code reader (spared no expense:)) that shows "NO CODES." I've used it on this vehicle before and it has detected issues that were fixed (O2 sensor stuff).

Seems like I should pick up a new crank position sensor and give it a try.

Can anyone give me a hint as to what this looks like and where it's situated? Really appreciate all the help!

John

Buy it here - probably cheaper than your local stealer.

Generally these are at the back of engine, where the tranny mounts to the engine.

Subscribe to MB EPC online http://epc.startekinfo.com/epc/ (it is free, believe it or not!)

Look up your car and engine. There's a picture in there when you get to the CPS page of where it is.

If you want to see what it looks like - go to the top of the page and click on buy parts. Pick your model and year. Find crank position sensor (probably under engine electrical). There's usually a picture of the part. All you'll see when looking for it though will be the wires going to it. Most of it is down in the rear engine/transmission cavity.

At AllPartsExpress it is under Electrical. There are 2 different ones depending on the VIN, I think, so make sure you get the right one. Pretty cheap though.

Just wanted to let everyone know that it was indeed the Crank Position Sensor that caused my starting problem. I wanted to summarize the issue for the next person...

If you have a 1999 C280 that will crank normally but not start when the engine is warm, then the crank position sensor could be your problem as it was in my case. Here are some note:

A 1999 C280 does not have an Over Voltage Protection Relay.

The Crank Position Sensor is located at the back of the engine on the driver's side. It points downward towards the crank like a spoke on a bicycle wheel. It's just in front of the transmission bellhousing.

To remove the Crank Position Sensor, I found it easiest to remove the plastic intake that connects at the back of the engine. This lets you see everything better and gives you good access.

After the platic intake is removed, you need to take the electrical plug off the Crank Position Sensor.

On my vehicle, the Crank Position Sensor is held in with one 8mm (E8) star pattern bolt. I picked up a set of these sockets at Harbor Freight for $7. They worked great. Remove the bolt and slide the Crank Position Sensor out. Real easy.

Now, make sure you look closely at your old Crank Position Sensor. You need to make sure you order a replacement with the correct electrial connection. In my case, the option was for 1) A two prong connector on the right and left of the CPS or 2) A single prong connector on the bottom of the CPS. Make sure you buy the correct one or your electrical connection will not snap back on.

I bought my CPS on Ebay for $47 shipped. It's a Bosch. The pictures on Ebay did a good job describing the difference in the quantity of electrical prongs.

Put the new CPS in and drive until the next gremlin materializes.

This website has saved me so much money that I wanted to make sure I could pass on the goodness!

Thanks for everyone's input and help.:)