Hi guys,
Haven't posted in a while.
Our 2002 R50 just turned the corner on 200,000 miles.
I've put a lot of effort into her over the years and we were doing ok after the last head and manual trans rebuild.

We got stranded on the freeway yesterday. Car just went pppppppuhh, with enough speed to barely pull over.

Had her towed home. It was nighttime so all i could do was
Pull the fuses and check for any burned fuses and reset them.

The next morning it started up. (after doing a quick spark test) JOY I thought. Then no love after that. I checked to see if I had spark, put a used plug in the #1 wire and grounded it with a jumper to the negative battery lead.

Seemed to have spark but wasn't convinced it was "not intermittent.

I could also get some momentary running with starter spray. But was causing some serious explosive backfires......

I was thinking maybe it was a bad coil. So, purchased a new coil, same result. Not firing up.

Seems like sometimes it wants to start though.

Unscrewed the little doodad pressure valve on the fuel rail and indeed it had pressure as fuel will squirt out. And you can hear the fuel pump go on in the back seat area when turning the key on.

Still not convinced I got a different spark plug and rigged it up so I could see the plug attached to the #1 wire through the windshield and I am convinced the original coil if firing now (it was getting dark again and the spark was easy to see).

Like a big dummy I finally plugged in my OBDII wireless WiFi module and ran an iPhone app to see if there were any stray codes. The "check Engine" light was not on, but decided to do this anyway.

Indeed I have a "confirmed" P0335 Crankshaft Position Sensor "A"circuit error and a
"pending" P0336 Crankshaft Position Sensor "A"circuit Range/Performance error.

Hmmm. I have only replaced the O ring on that little guy when I rebuilt the top end last time, about 2 years ago. Maybe the sensor is shot? Or wire popped off?

Also I've heard that low battery voltage can cause issues. My battery is measuring about 12.3 volts when sitting. It is enough to turn the starter but maybe the cranking amps are not consistent enough to keep the engine going. This battery is less than 2 years old, maybe only a year old.

I just want to make sure if I have to put this mini in "front end service mode" the crankshaft sensor is really the issue.

Has anyone replaced one without taking the whole core support off? Ugh If done this about 4 times and not looking forward to it...

Thanks for any help!

 

The cam position sensor is a common failure and I would most likely replace both it and the crank position sensor.
It may also throw OX sensor codes, but try to clear them, before you do anything with them, as they are common to come on with Cam and Crank sensor failures.

 

Thanks, Going to try and source an affordable one around here or get one via mail asap. I really don't want to pull the front end off and just saw a guys vid where he removed the air box and throttle body and was able to access it. Possible?

 

the cam sensor requires the passenger side upper motormont to be removed, which is easy, if you support the engine from below. The crank sensor is also replaceable without removing a bunch of stuff, but it is tight quarters!
Amazon has them both for a reasonable price.

 

Moving you the Stock Problems/Issues area.

Hope you are able to keep it running.

 

Do you access the Crankshaft position Sensor from the top, by removing the throttle body?

 

No, from underneath!

 

you get to it underbeath:
This is a S ,but it is in the same location, but easier to get to!.

 

has anyone swapped out the crankshaft position sensor without putting the car into front end service mode, removing the front end bumper, core support, front wheels and crush tubes?

i just can't remember if there is enough room to get so much as a ratchet and arm up in there.

 

Both camshaft and crankshaft sensors have been mentioned in this thread.

Just to be clear, here are approximate indicators of where they both are located;

Camshaft position sensor on the passenger-side of the head.
(Requires passenger-side engine mount to be removed, and engine supported from underneath to replace)

Crankshaft position sensor on the front of the block, towards the gearbox.
(Requires full or partial front-end service mode to get in)

 

It is doable without going into service mode. Remove the underbody tray (if it's still there), and you can access the sensor from there. It's tight, but there's only one bolt and one electrical connector, not too much to worry about.

 

It's certainly doable; if your arms look like the dude below...
But for the rest of us who are more "well-fed," your options are:

A) Do a partial f/e/s/m (only remove outer and inner bumper) and slide the entire core support forward on long 8mm bolts (a'la Mod MINI) to get from the bottom.

B) Do a partial f/e/s/m, disconnect the top radiator hose at the upper-left connection (you'll lose about a half-cup of coolant), disconnect top of radiator and a/c condenser from core support, and gently tilt radiator forward, holding it while you replace sensor...

C) Remove the lower rear engine mount and lever the engine backwards while you snake your arm up the front-side of the block and work blindly and by feel.

 

Thanks guys, Hoping to get the part by Friday. Will let you know how it goes!

 

Not sure on the R50 if you have to remove the engine bracket or not. But same location.





I believe the cam and crank position sensors are the same with how they “lock” into position. Before you jump in, try playing with the ignition coil pack connector. It has the same locking mechanism as the camshaft and crankshaft sensor…

Locked:


Unlocked and can be pulled apart:


Reinstalled and locked:


Crankshaft location in front (tight fit)




Bolts should be 10mm each that secure the sensor in place. Tightening should be snug, no gorilla torque.

Hope this helps

 

This does help. On the crankshaft position sensor picture, are you looking "UP" into the front of the engine (lying on your back) ?

I've done this before with the front end off. Just don't feel like pulling it off if'n I don't have to :-)

 

Nope, that should be looking head on. I believe this was last year for me when I had the car in service mode. I tried to think of replacing everything I could while it was apart. Started with replacing the radiator at first...

First shot is head on with the sensor connected.

Second pic is head on but a tad lower to show the sensor dangling.

Its pretty straightforward but the red locking piece tends to throw people for a loop because space is tight and visibility is poor.

 

B) Do a partial f/e/s/m, disconnect the top radiator hose at the upper-left connection (you'll lose about a half-cup of coolant), disconnect top of radiator and a/c condenser from core support, and gently tilt radiator forward, holding it while you replace sensor...


this may be what I have ti try first as the car is parked on the street, doesn't run, tilted at an annoying street angle and can' t lift on jacks and can't drive onto ramps https://www.northamericanmotoring.co.../impatient.gif

 

I managed to take the airbox out and moved the air inlet hose out of the way to gain access to the Crank position Sensor. Very tight and had to feel my way around in there to get a multiple adapted socket and small racket in there to extract the bolt. Fitting the new one, I used a bent antenna style magnet to position the bolt after fitting the new CSPS in the hole, whist enjoying a good 45 minutes of yoga.

Car still doesn't start.

Would a bad "cam" shaft position sensor also throw a P0355 and P0336 error code?

Out of ideas.

 

Ok, The P0355 code indicates a defective ignition coil. Even if you replaced it, the new one may be bad also.
It is not uncommon for the plug at the coil to corrode and keep the engine dead, so take the plug off and clean both the coil and plug with contact cleaner. (I think it may be this)
The P0336 code is the crank position sensor.

If the cleaning does not fix it, it may be ecm or wiring failure.

 

Thanks.
It is a P0335 not P0355 code :-)
But your advice is good as well.

I've had 3 computers and 2 BCMs in this car.

 

Yesterday I replaced the Camshaft position sensor as well. AND I cleaned the Coil terminals.

Checked the compression too - (145 to 165 all the way across)
I was told that sometimes the 2 sensors throw codes and replacing both is necessary to troubleshoot. However, this did not change the result. I tried to do an ECU rest procedure but just realized the orange digital display on the Tach is is blank with only 2 pixels showing in the upper left. Could this be indication of ECU failure? Or low battery? This battery is tired from cranking.

 

I am not sure about the two pixel thing, but it is possible that you have not completed the reset. Try disconnecting the battery, leave it disconnected for a few minutes before connecting it again.
Also make sure the fuel pump is running when ignition is first turned on.

 

I have never been able to initiate that reset. Possibly due to the ECU DME EWS Key swap that had to happen a while back. And now the screen is blank. Guess this screen issue happened a while ago and my wife never told me :-/. Not sure if these issues are related but not being able to do a reset does not sound usual and customary.

I had the battery disconnected for an hour or so when doing the cam sensor swap. Then I charged the battery.

 

I guess I'm beating up this thread pretty well. Thanks to all for your input. Has anyone ever tested the wiring starting at the fuse box next to the battery? I might have to buy or rig up a continuity tester as well as get my hands on a 2002 R50 wiring schematic. I don't have a multimeter that has ohms on it, but assuming a simple "bleep" tester would do, no?

 

I am thinking that Item # 0015 of the below thread will get you a schematic.

https://www.northamericanmotoring.co...questions.html