GTI error code help

[Mike_M]

My mate used VAG COM to turn on the auto lock/unlock feature and found this fault code.

We took note of it and cleared it, then disconnected the battery for an hour before putting back together.

I drove the car for a couple of days and then we checked the car to get the code back again:

Could it be afaulty sensor as thereappears to be nothingwrong the car starting etc:

1 Faults Found:

17911 - Load Signal from Alternator Term. DF: Implausible Signal

P1503 - 35-10 - - - Intermittent

Found this on a site:

17911 - P1503 - Load signal from Alternator Term. DF Range/performance/Incorrect Signal

[Snoopy]

Few possibilities:

1. Dodgy connections - check tightness of battery connections (with a spanner - even if they don't look loose they might be!) and alternator connections.

2. Dodgy voltage sensor in the alternator - the DF wire comes from the voltage sensor to the ECU and dash, and is used (amongst other things) to trigger the warning light on the dash.

3. Dodgy alternator.

First one should be pretty easy to check.

Second one, I'd try using a voltmeter to check the alternator output voltage (when the car's running!) and compare it with the voltage reported by VAG-COM. The multimeter should read around 14v when the car's running. If VAG-COM differs significantly from the multimeter, then the sensor in the alternator is knackered.

Third one, same test, but if the multimeter and VAG-COM both read a low voltage (i.e. under 13V when the engine is running) then it looks like a faulty alternator.

Bear in mind that as it's intermittent that the symptoms might not show up all the time.

[Tigz™]

Third one, same test, but if the multimeter and VAG-COM both read a low voltage (i.e. under 13V when the engine is running) then it looks like a faulty alternator.

Makes sure you check all three connections.

Check :

• Alternator > Battery Positive
  
• Chassis > Battery Negative
  
• Engine Block > Battery Negative
  

[Mike_M]

Cheers for the info style="vertical-align:middle" emoid=":)" border="0" alt="smile.gif" />

Will investigate a little further and also got it booked into VW to look at.

[Mike_M]

Checked my voltages and everything appears to be fine.

Cleaned the alternator terminal and when I went to the battery found the ground cable a little loose style="vertical-align:middle" emoid=":o" border="0" alt="ohmy.gif" /> but not loose enough for it to fall off, so not sure if this was the problem

All tightened up and going to get the fault codes removed so I can see if it comes back again.

Cheers and fingers crossed.