No Start with P0171 and P0174
12-13-2014, 01:02 AM
#1
Junior Member
Thread Starter
Join Date: Dec 2002
Location: Vallejo, Ca
Posts: 66
Likes: 0
Received 0 Likes
on
0 Posts
No Start with P0171 and P0174
My W209 CLK 500 stalled while driving on the freeway. Pulled the CEL codes and came up as p0171 and P0174. It cranks but it doesn't start up. I already changed the MAF sensor with an OEM Bosch one and erased the codes with my scanner. Still not able to start after. Any ideas? Thanks
Brandon
Recap as of 1/10/15
Parts Changed so far:
MAF
Fuel Pump Relay
Crankshaft position sensor
Spark Plugs (Preventive maintenance)
Still no Fuel Pressure at Schrader Check Valve and no start just cranking
Brandon
Recap as of 1/10/15
Parts Changed so far:
MAF
Fuel Pump Relay
Crankshaft position sensor
Spark Plugs (Preventive maintenance)
Still no Fuel Pressure at Schrader Check Valve and no start just cranking
Last edited by sLickfITY; 01-11-2015 at 01:06 AM. Reason: Addition is sentences
12-14-2014, 11:21 PM
#2
MBworld Guru
Those codes should not cause a stall or prevent the engine from starting. Something else like a bad fuel pump or crankshaft position sensor is likely the cause for it not starting.
12-26-2014, 10:49 PM
#3
Junior Member
Thread Starter
Join Date: Dec 2002
Location: Vallejo, Ca
Posts: 66
Likes: 0
Received 0 Likes
on
0 Posts
I feel like i am starting to throw parts at the car now. I assumed it is a fuel problem so I recently checked the fuel pressure at the schrader valve and the engine is not getting any pressure. I checked the fuel pump fuse and checked it for power and it seems to be working fine. Today i went and bought a new fuel pump relay and replaced it but it still does no start just cranks away. I have researched symptoms of a bad CPS (crank) and that looks like what i will be changing next before I make the big jump and replace the fuel pump. I am just a little confused with the CEL codes it has and how it relates to a bad CPS. Can anyone provide their input? Thanks
Brandon
Brandon
Last edited by sLickfITY; 12-26-2014 at 10:52 PM.
12-26-2014, 10:51 PM
#4
Junior Member
Thread Starter
Join Date: Dec 2002
Location: Vallejo, Ca
Posts: 66
Likes: 0
Received 0 Likes
on
0 Posts
Also, since i have been working on this car i decided to be proactive and perform some preventive maintenance and change the spark plugs, valve cover gaskets, and serpentine belt since the car has 174k miles now
12-28-2014, 12:32 PM
#5
MBworld Guru
The CPS detects engine rotation. If it does not get a signal, then it will disable the fuel pump as a safety measure (no need to keep pumping fuel when the engine isn't running). And often, you will get no error when it fails - just no fuel and no firing. So yes, I'd look at that.
12-28-2014, 04:15 PM
#6
Senior Member
Join Date: Jul 2013
Location: Northern VA
Posts: 264
Likes: 0
Received 2 Likes
on
2 Posts
2003 Chevy Tahoe
Just did a CPS swap out last week. Exact same symptoms as fity-cent. Got the Bosch CPS from AutoHaus. Massive PITA to swap out, but only cost me $65 instead of $400 at the dealer.
01-11-2015, 12:05 AM
#7
Junior Member
Thread Starter
Join Date: Dec 2002
Location: Vallejo, Ca
Posts: 66
Likes: 0
Received 0 Likes
on
0 Posts
I swapped out the crank position sensor today with a Bosch one that i received from Autohausaz and still no dice. Car still does not start up, it just continues to crank. The #4 fuel pump fuse is getting sufficient power but there is no fuel pressure at the schrader valve. Would the camshaft position sensor cause the same symptoms or should i just go and replace the fuel pump now?
