Crankshaft Position Sensor (Crank, no start)
Thread Starter
Junior Member
Joined: Jan 2007
Posts: 41
Likes: 10
From: Sydney, Australia
SL55 2003 Obsidian Black, 2007 ML500
Crankshaft Position Sensor (Crank, no start)
There are a number of posts on this topic but I found the DIY repair easier than described in some posts.
Here's my version:
2002 ML500 143,000km Australian Compliance
Symptoms: 1. Intermittent failure to start when hot... cranks but no start
2. Always starts later, a few minutes to 20 minutes
3. Cranky wife.
Searched various forums which pointed to the Crankshaft Position Sensor failing
Analysis with Carsoft 7.4 detected stored and actual error code P2034 Crankshaft Position Sensor (P0335)
I bought the sensor from an independent supplier (Silverstar Spares, AUD$150 delivered next day). My local dealer wanted AUD$302. The allocated time for this job is two hours...AUD$280
I was prepared for a big job...the forums suggested that it was an OK job on the V6 but a PIA on the V8. Some writers suggested removing the LHS front wheel and plastic dirt shield.
The Repair:
You need a torch, an E8 Torx socket and a 1/4" drive with at a least 10" (250mm) extension.
Holding the torch in your right hand position the Torx socket, extension and ratchet with your left hand over the CPS bolt behind the LHS cylinder head (see attached photos).
Loosen the bolt with the ratchet then remove the ratchet from the extension and undo the bolt with the extension and your fingers then remove it being careful to tip the extension down on the outer end so that the bolt doesn't fall from the socket as you withdraw it.
Holding the wire to the sensor gently pull it to withdraw the sensor from it's hole.
Squeezing the plug to unlatch the catch, gently remove the plug from the sensor.
Put the plug onto the new sensor, place the sensor back in it's hole and rotate it so that the hole lines up with the thread in the engine.
Place a small thin piece of cloth (I used a piece of "Chux") over the end of the socket and insert the bolt head into the socket. Give the bolt a gentle tug to make sure that it slips out of the socket easily, but not easily enough to fall out as you attempt to insert the bolt back into the threaded hole.
Gently lower the bolt/ socket/extension towards the threaded hole, tighten the bolt by hand then use the ratchet to lock it up.
That's it!
It took me ten minutes.
It took me a further 5 minutes to withdraw the piece of cloth that had become trapped beneath the head of the bolt.
The car started first go, I'll post a follow up if it doesn't fix the problem.
Good Luck!
Peter Cowie
Sydney
Australia
Here's my version:
2002 ML500 143,000km Australian Compliance
Symptoms: 1. Intermittent failure to start when hot... cranks but no start
2. Always starts later, a few minutes to 20 minutes
3. Cranky wife.
Searched various forums which pointed to the Crankshaft Position Sensor failing
Analysis with Carsoft 7.4 detected stored and actual error code P2034 Crankshaft Position Sensor (P0335)
I bought the sensor from an independent supplier (Silverstar Spares, AUD$150 delivered next day). My local dealer wanted AUD$302. The allocated time for this job is two hours...AUD$280
I was prepared for a big job...the forums suggested that it was an OK job on the V6 but a PIA on the V8. Some writers suggested removing the LHS front wheel and plastic dirt shield.
The Repair:
You need a torch, an E8 Torx socket and a 1/4" drive with at a least 10" (250mm) extension.
Holding the torch in your right hand position the Torx socket, extension and ratchet with your left hand over the CPS bolt behind the LHS cylinder head (see attached photos).
Loosen the bolt with the ratchet then remove the ratchet from the extension and undo the bolt with the extension and your fingers then remove it being careful to tip the extension down on the outer end so that the bolt doesn't fall from the socket as you withdraw it.
Holding the wire to the sensor gently pull it to withdraw the sensor from it's hole.
Squeezing the plug to unlatch the catch, gently remove the plug from the sensor.
Put the plug onto the new sensor, place the sensor back in it's hole and rotate it so that the hole lines up with the thread in the engine.
Place a small thin piece of cloth (I used a piece of "Chux") over the end of the socket and insert the bolt head into the socket. Give the bolt a gentle tug to make sure that it slips out of the socket easily, but not easily enough to fall out as you attempt to insert the bolt back into the threaded hole.
Gently lower the bolt/ socket/extension towards the threaded hole, tighten the bolt by hand then use the ratchet to lock it up.
That's it!
It took me ten minutes.
It took me a further 5 minutes to withdraw the piece of cloth that had become trapped beneath the head of the bolt.
The car started first go, I'll post a follow up if it doesn't fix the problem.
Good Luck!
Peter Cowie
Sydney
Australia
