jvakos

was driving this week in the chicago cold of 15-20 farenheit and some strange things happened....first was after driving for 5 minutes i pulled in to a gas station and filled with gas, then the car would not start it would just crank but never turn over. i pushed the car into a parking spot at the gas station and tried to restart after 5 minutes and it fired right up. No codes or anything and it was driving fine for 2 days. yesterday i drove and immediately when starting up it showed 2 malfunctions of the ABS/Brake Assist and ESP not working. my obd reader showed a P0500 vehicle speed sensor code as "pending" and the car would still drive normally but had thos 2 malfunctions for about 15 minutes. i restarted the car several times and manually pushed the ESP a few times and then the 2 malfunctions disappeared and everything is fine.

is that a fluke due to the cold temps perhaps, or is the p0500 code as "pending" a warning that my Vehicle speed sensor is about to die????

there is only 1 other post on the boards about a p0500 code and not finding much on the web about it with these cars so curious for any ideas

thx!

C230 Mulac

There are 4 speed sensors, one at each wheel. They are about $50 a piece.

The ABS/ESP computer is one and the same. If one of the speed sensors goes bad, your ABS/ESP will not work, hence the warnings.

The only real way to find out which wheel is bad is by hooking up STAR, putting it in road test mode where it shows the readings from each wheel, move a few inches and the one where the value stays at 0 is the bad sensor (this is what I did when I had a bad speed sensor.

Only other way I can think of to find which one is bad is to get the new one, swap one wheel, see if warning comes on, then next wheel, then the next, until it goes away. Painful but can be done if you don't have a STAR computer.

C230 Mulac

Should have mentioned, it's pretty easy to replace; one electrical connection at the top of the wheel well and then one bolt that holds it to the back of the wheel hub.

jvakos

Petar - really appreciate the input and thanks so much. I will ask my indy shop guy if he has a STAR or may need to get it to the dealer.

Do you know - would the car not start due to a bad speed sensor?

I had 3 times my car didnt start this past 2 weeks and showed that P0500 code, but strangely when I put the car in neutral and manually pushed the car 4-5 feet and tried to start it again it worked and code was gone.

not sure if coincience that moving the car had anything to with the sensor and starting again????? wierd.

C230 Mulac

No problem

Not sure about the car not starting thing, has it been really cold in your area lately? If your battery hasn't replaced in a while it could be starting to go bad and cold weather can really be hard on batteries nearing the end of their life.

The other thing is the common crankshaft position sensor. About a $45 part and not too terribly difficult to replace. That can cause intermittent starting or very long cranking before finally turning over.

jvakos

yeah its definitely strange... battery cranks right up as its 2 years old but it wouldnt turn over. the CPS was just replaced and thats what i initially thought it was and assumed maybe the bosch CPS replacement part already went bad. but since it started up after pushing it 4-5 feet it has me confused totally as to what it could be.

the p0500 code is gone right now and as its been "slightly" warmer in chicago (30+ degrees farenheit) the car starts up fine.

maybe in her old age my c32 just doesnt like the cold temps

C230 Mulac

The Bosch CPS should be fine, I believe that is the OEM. I don't know if the speed sensor would have anything to do with it not starting, doesn't sound right, but who knows it could be anything. Either way, sounds like you need a speed sensor regardless so you can start there and see what happens.

gwin

can I ask what OBD reader you're using?

jvakos

using this Actron obd2 scanner and it works very well. also bought the ipone app "dashcommand" and the needed hardware which is a wifi odb2 scanner from PLX called "kiwi2" and that also works to check codes and clear the codes. if you have an out of warranty benz you absolutely need to get one of these to verify issues and codes so the dealer doesnt rob you

https://actron.com/content/obd-ii-autoscanner
http://www.palmerperformance.com/pro...hone/index.php
http://www.palmerperformance.com/hardware/index.php

gwin

thanks man

I first tried Torque with a bluetooth OBD2 and I couldnt pick up codes. Which is why i went with Autel MS509, which also couldn't pick up the codes.

darn it!

gwin

I just tried Dashcommand with my Vgate OBD Scan, and it wouldn't pick up codes either hm....

jvakos

Gwin - hey man. yeah i researched these OBD2 wifi devices and read a bunch of amazon reviews and most indicated that the bluetooth ones were not very reliable.

I got one from PLX the Kiwi2 wifi OBD2 device and it connects pretty consistently to my iphone and dashcommand app that i added. it can show the codes and a bunch of other options like checking HP, torque, fuel, temps, 1/4 mile and 0-60 time and a bunch more from dashcommand.

I am sure there are better apps than Dashcommand but i bought those two based on amazon and other reviews on the web. If a code reader is all you want, then that Actron device i mentioned works great to check codes, clear them, and do drive cycle monitoring if you want. its about $65 USD and connects with a hard line (not wifi or bluetooth)


https://plxdevices.com/product_info.php?id=GSST2WIFI

interesting update to my original post is since the chicago weather has been in the 40+ range my car has not had any starting issues!!! wierd