Technical Car/Motor Issues > Volkswagen Polo III - 01 1.4 Crankshaft Position Sensor - Fault Code
Thread Author: Pezzer Replies: 15
View Threaded 

New Thu 23 Jan 14 12:51 
 Volkswagen Polo III - 01 1.4 Crankshaft Position Sensor - Fault Code - Pezzer
My son's Polo has had a series of issues, initially the Clutch went and was replaced, however whilst waiting for this the battery flattened and needed charging, all was well for a few days and then he had a flat battery again when visiting a friend. His friend at Halfords put a meter across it and pronounced that his alternator wasnt charging properly. So he salvaged an alternator from the local scrappy but that also did not appear to work. So a new one was ordered which he fitted with his friend; initially they had problems getting it started but eventually it seemed to work.

However since this has been fitted he is now experiencing intermittent running problems, including cutting out, failing to re-start, limited revs. My fault code reader indicates a Crankshaft Position Sensor fault code.

Before we just replace the sensor I would appreciate your views on whether this seems like the correct course of action or whether there might be something else worth checking ?

Thanks in advance
Reply to this message | Report message
       
New Thu 23 Jan 14 13:29 
 Volkswagen Polo III - 01 1.4 Crankshaft Position Sensor - Fault Code - Number_Cruncher
If you clear the codes, does this code come back?

I should mention that some systems will always report a crankshaft position sensor fault code when the engine isn't running - it can mean nothing.
Last edited by: Number_Cruncher on Thu 23 Jan 14 at 13:31
Reply to this message | Report message
       
New Thu 23 Jan 14 13:46 
 Volkswagen Polo III - 01 1.4 Crankshaft Position Sensor - Fault Code - carmalade
A faulty crank sensor would certainly cause the problems you have.The only issue you may find,is that on some engines the crank sensor sits in the starter motor aperture,so this needs to come out first.It is only older efi systems from the 80s and 90s that throw a crank sensor fault with the engine not running.hth
Reply to this message | Report message
       
New Thu 23 Jan 14 13:52 
 Volkswagen Polo III - 01 1.4 Crankshaft Position Sensor - Fault Code - Pezzer
Will certainly give this a try not sure whether son cleared it. Yes I believe the sensor is indeed obscured by the starter motor, hence thought it worthwhile asking before we decide what to do.
Another question where would the other end of the sensor cable connect to ? I would like to check it isnt loose or has been dislodged by the previous actions ?
Reply to this message | Report message
       
New Thu 23 Jan 14 17:18 
 Volkswagen Polo III - 01 1.4 Crankshaft Position Sensor - Fault Code - carmalade
There are 2 types of sensor on these .The difference is the length of cable.One terminates to a connector below the inlet manifold ,and the other type can be found near the cambelt cover,at the end of the inlet manifold.I would think it unlikely to be a connection problem as these are fitted with a positive lock tab that engages when the connection is made.hth
Reply to this message | Report message
       
New Fri 31 Jan 14 15:18 
 Volkswagen Polo III - 01 1.4 Crankshaft Position Sensor - Fault Code - Pezzer
Quick update: Thanks for the advice, it was indeed the CPS although it was not duff, but rather covered in some of the swarf/fragments from the clutch as it is magnetic, so the garage we took it to just cleaned it up and put it back and said give it a try and if it does need replacing they will only charge for the part.
Reply to this message | Report message
       
New Thu 6 Feb 14 11:50 
 Volkswagen Polo III - 01 1.4 Crankshaft Position Sensor - Fault Code - Pezzer
Hmm, problems returned so Sensor has now been replaced which has made no difference and the problems remain - misfiring/not starting ...... grrr
Reply to this message | Report message
       
New Thu 6 Feb 14 11:59 
 Volkswagen Polo III - 01 1.4 Crankshaft Position Sensor - Fault Code - swiss tony
>> Hmm, problems returned so Sensor has now been replaced which has made no difference and
>> the problems remain - misfiring/not starting ...... grrr
>>

Genuine or patten part?
Reply to this message | Report message
       
New Thu 6 Feb 14 13:06 
 Volkswagen Polo III - 01 1.4 Crankshaft Position Sensor - Fault Code - Pezzer
VW's finest - patten was not available
Reply to this message | Report message
       
New Thu 6 Feb 14 14:00 
 Volkswagen Polo III - 01 1.4 Crankshaft Position Sensor - Fault Code - carmalade
You will need to check live data from the engine control system to make sure there is an accurate engine rpm signal.Also check data from engine coolant temp sensor,as these are notoriosly unreliable.hth
Reply to this message | Report message
       
New Thu 6 Feb 14 14:07 
 Volkswagen Polo III - 01 1.4 Crankshaft Position Sensor - Fault Code - swiss tony
>> VW's finest - patten was not available
>>

OK,that probably rules that out.
As carmalade says, time to get the car checked out properly.
Reply to this message | Report message
       
New Thu 6 Feb 14 18:48 
 Volkswagen Polo III - 01 1.4 Crankshaft Position Sensor - Fault Code - Number_Cruncher
The fault code should be used as the starting point in finding the fault, rather than the answer.

Reply to this message | Report message
       
New Wed 12 Feb 14 14:47 
 Volkswagen Polo III - 01 1.4 Crankshaft Position Sensor - Fault Code - Pezzer
Further update: Vehicle sent to their Electrical specialist (!!?) and has now had Camshaft sensor replaced. This seems to have partially cured the problem and when the car starts it runs without a problem. There is however still a starting problem and it will sometimes take a few goes for the engine to start properly. It initially catches but immediately cuts out. It does go with a bit of patience and leaving the key turned on for a few seconds, possibly allowing the fuel pump to gain pressure seems to work - hence suspicion now turning to the fuel pump/filter.

Beginning to think the crank sensor was a red herring.
Reply to this message | Report message
       
New Wed 12 Feb 14 17:47 
 Volkswagen Polo III - 01 1.4 Crankshaft Position Sensor - Fault Code - carmalade
You have not mentioned what scanner you are using,but many of the happy shopper models give inaccurate info.It would be interesting to establish what rpm speed is being logged when cranking,and also coolant temp is displayed;is it within range?The only way to check fuel pressure is to get a gauge on the line,or connected to take off port.
Reply to this message | Report message
       
New Thu 13 Feb 14 16:06 
 Volkswagen Polo III - 01 1.4 Crankshaft Position Sensor - Fault Code - maltrap
Hope i'm not throwing you a "red herrimg" but my wife's Polo had similair symptons to yours, my VW technician/contact said it was probably the coolant temp' sensor. This cost me £15 from GSF & did the trick.
Last edited by: maltrap on Thu 13 Feb 14 at 16:07
Reply to this message | Report message
       
New Fri 14 Feb 14 09:59 
 Volkswagen Polo III - 01 1.4 Crankshaft Position Sensor - Fault Code - Pezzer
Initially was using an ebay special Maxiscan. However have backed off this and left it with the garage.
Reply to this message | Report message
       
Latest Forum Posts