OBDII Scanner help needed

[FreeLitres]

I already posted this in GG but had no response. Can anyone help me?

I have an engine management light in my 2003 Jag X-Type 3.0 and I am trying to find the cause of the problem to see how serious it is. I have an OBDII Scanner (Autel Geniscan GS400) which connects to the car ok but says that there are no error codes and that the Malfunction Indicator Light (MIL) status is ‘off’. The MIL is definitely lit up on the dash when I drive the car though.

My questions are:
1) When the MIL light is on, should you always see an error code on the OBDII?

2) My OBDII scanner says the light is off, so is it a broken/duff scanner?

I actually bought this scanner a couple of years ago from ebay when I had another MIL on. At that time, the scanner said that the MIL light was off and that there were no error codes. I took the car to the garage and they said it had a faulty O2 sensor which they changed.

Do manufacturers use the MIL light as a "service due" indicator?

[TheEnd]

I guess there is a problem. Can it read any data from the car, and does it confirm it is connected to it?

[FreeLitres]

TheEnd said:

I guess there is a problem. Can it read any data from the car, and does it confirm it is connected to it?

I'm not very confident with this scanner and have never 'got it working' when I have an engine light on. The connector fits and I do not get a 'link error' which I would be expecting if the connection is not made. During the scan, the display shows something like "downloading data from car" which makes me think it HAS connected.

Does this sound like a duff scanner, or does a MIL light sometimes show when there isnt really a problem to diagnose? (i.e. as a service due indicator?)

[TheEnd]

it shouldn't really put the light on without an error, providing it is the check engine light you are looking at, and not just a service light.

have you got it to work with any other cars?

[paintman]

You may have a faulty reader.
I believe there can also be problems with the generic type readers not showing codes/failing to correctly identify fault codes which the dealers make-specific ones will have no problems with.

Edited by paintman on Wednesday 23 December 17:38

[FreeLitres]

TheEnd said:

it shouldn't really put the light on without an error, providing it is the check engine light you are looking at, and not just a service light.

have you got it to work with any other cars?

I haven’t tried it with another car. The wife’s car is a VW (requires VAG-COM or something?)

I will be well annoyed if its a dodgy scanner. It arrived brand-new looking with immaculate casing and transparent sticker over the display screen.

The only thing I am not sure about is whether the X-Type displays the engine warning light when its due a service. Could this be the case?

[TheEnd]

It should say SERVICE or show a spanner.

It should also work with the VW, infact, it should work on every car in the UK post 2003, but VAG COM is far more powerfull.

What you have is an OBD2 code reader, which is a standardised set of fault codes that every car manufacturer has to use for basic emissions errors. They will run on a few different protocols, and i'd have a feeling yours should be PWM.
It might autodetect, if not, you'll want ISO for the VW and try PWM for the jag. If that doesn't work, try the other options, or if you get no options, then you can ignore this bit.

See if there is an option for live data, and make sure the ignition is in the run position too, you should get displays of coolant temp and rpms on the reader if it is connected.

[melhookv12]

X Type's don't have servise lights. If the check engine light is on with car running there is a fault, but maybe the system flagging the fault isn't the ECM, do your brake lights work.....??