Hi All,

I have had a clutch and dual mass flywheel change 2 months ago. Since then, I have noticed the engine warning light pop on.

Took it to the garage, and they ran a computer diagnostic (local garage and trusted). The error code brought up oxygen sensor faults. The mechanic loaded the vehicle onto the ramp and checked all 4 sensors were plugging in - which appear fine.

He cleared the faults and the light disappeared. When restarting, it brought 1 fault back out of the original 2.

He suggested there was also a low voltage error and borrowed me his charger as the battery measured in an 11.75v with engine switched off. I charged the batter for about 2.5 hours before the charger told me it was fully charged (I didn't measure the charge and assumed it was fully charged).

When I went back to the garage the following morning to investigate further, the light was still on. The engineer ran another error scan and the following codes are the culprit:

P1646 - heated oxygen sensor control module, bank 1 open/shorted
P1647 - heated oxygen sensor control module, bank 2 open/shorted
C1145 - wheel speed front right input circuit failure
P1582 - flight recorder data is stored
P2503 - charging system voltage low
P1000 - system check not completed since last memory clear

The test also gave the following info:
Oxygen sensor equivalence ratio bank 1 upstream = 1%
Oxygen sensor equivalence ratio bank 2 upstream = 1%
Oxygen sensor current bank 2 upstream 0A
Oxygen sensor bank 1 downstream 0.03V
Oxygen sensor bank 2 downstream 0.03V
Heated oxygen sensor bank 1 downstream off (this was switching off/on regularly during test and revving)
Heated oxygen sensor bank 2 downstream off (this was switching off/on regularly during test and revving)

The battery test gave the following results:
12.27 V
Measured 487A / Rated 740A
Starter test: 10.66V
Charging test 15.07V

He reset the codes. When I left, stopped and restarted the car and the light was off and remained off until I stopped for fuelling at approx. 2 miles. After refuelling - the engine light came back on and remains on.

Had another check on the battery by another garage, battery dialled in at 60% health and was suggested 'good battery'.

During the last 2 months - I have seen the dashboard battery light flicker on and off briefly a couple of times.

I am not sure whether the sensors are getting enough voltage for heating or whether the sensors are faulty and require replacing. I am also assuming that as the light was off for a few miles - there is no problem with break in wires etc.....

When starting from cold - it struggles a little for oxygen and with my chemistry backgroud - I assume the sensors are not proportioning oxygen correctly to the combustion gas mix.

Anyone experience this and find the root cause? I will take advice on how best to approach this as I could easily bark up the wrong tree.

My mechanic suggests using a better charger (snap on) and charge over a weekend due to the charging mechanisms in x-types.

Any advice gratefully received.

Many thanks

Chumbers

2002 X Type V6 petrol 2.5 - I've had this since new. 106,000 miles.

 

Chumbers, from our experience (non qualified mechanics in most cases), having the battery down as low as it is (battery life), this is the source of your problems. yes, for most cars, 60% life is probably fine. Your kitty is a bit more picky. They like it up at over 75% if not at 100%. So, put a new battery into the car and see what you have then. Replacing the battery should clear all your codes (tell the company to not save the memory of the car, you want it erased, they will probably look at your funny). By loosing all power to the car, this is going to do a few things to you. The most important will be erasing any codes that are stored in the ECU. It will erase the memory for the radio (no big deal in most cases). It will remove the auto up/down for the windows and sunroof. But, do not worry as these are all easily reprogrammable.

Get the new battery put in and see what you have then. I have a feeling you are going to find that these codes are going to go away.

As for resetting the radio, well, not much to say about that other than spending the time finding the radio stations that you like.

As for resetting the windows/sunroof, this is pretty straight forward. Pick a window (starting in the full up position) and push the down button for the window and hold it there till the window reaches the full down position. Do no lift on the switch and hold it there for another 3-4 seconds (may hear a relay click happen during this time). After the 3-4 additional seconds or hearing the relay click, release the down button. Now, lift up on the switch to raise the window. Again, let the window go fully close and continue to keep the switch lifted for 3-4 seconds after the window closes or you hear the relay click. Repeat for the other windows/sunroof.

 

Great - many thanks. The mechanic was suggesting something to do with the charging mechanism and I even went as far as looking at new batteries - as I was convinced its the battery.

It's about 2-3 years old - and I think a new battery is also the solution.

Many thanks for the clarification - will get this sorted and keep you posted.

Best regards,

Chumbers

 

Hi All,

Quick update on this thread. I had attempted to charge the battery a couple of times on a 2 amp charger as it had 540amps - this was done over a weekend and I managed to get at least 50 hours charge. When the battery was retested - it still came up at 12.2v or less with no more than 550 amps - which was a bit of a surprise. I guess the charger stops charging as it 'thinks' the battery is fully charged (or perhaps I should have disconnected it before charging). This was done with a couple of different battery chargers.

In the end, the errors were still there and I had a battery change. With the change, almost all the errors cleared with exception of P1000 and P1582.

The MIL is now out and oxygen sensors read fine - good news for me as it means it should pass it's MOT next month.

If anyone has ideas on the consequence of the remaining 2 error codes, that would be much appreciated.

Thank you all for your help.

Regards,

Chumbers

 

I have two XJs and an S type. My brake would not disengage when putting the car in Drive. I've seen on this forum many comments about electrical "issues". I replaced the battery and have had no emergency brake issues since then. Our newer cars pull so much energy, that I've started to limit the age of my batteries to around three years. Although money is an issue with some people, with these newer cars and EVERYTHING having a sensor on it, our cars require so much more juice. I have changed all three batteries on all cars and will continue to do so around every three years. There were many posts about the beginning warning of a lower battery would be a parking brake not releasing. I have not had the issue of the parking brake since replacing the battery. The cars start quicker and it might be my imagination, but I think all the lights, illumination is brighter.

 

P1000 is not an error - it is a status code
P1000 - system tests not completed since last code clear
P1111 - system tests complete
one or the other will always be present

P1582 - Flight Recorder data saved.
an error has caused diagnostic data to be saved in memory
requires dealer level system to retrieve
Since you have corrected the problem should be no concern.

 

It's ironic that after my post, the light returned....

I've not been back to have the codes read yet, but the first set of readings provided much less codes.

 

chumbers, I have the same problem with the MIL and the P1646 and P1647 errors, I have change both upstream heated O2 sensors, erase the codes and the MIL always return. Doesn't know that may be the battery...so before changing it and spend more money, ¿can you tell us if you have solved the errors?

Thanks a lot!

 

Hi dark_gap,

Initially I had many codes and changed the battery when I thought it may also solve my O2 sensor problem. After changing the battery, the light went off for about an hour and returned. As it was due to have an inspection (MOT), the mechanic told me that the faults are for the sensors for O2 - 2 lambda sensors downstream that needed changing. However, at 2K revs, it was within it's limit for readings.

The only thing I can suggest is that the new battery gave the sensors a better warm up and ability to read, whilst the old battery was on it's way out. I am suspecting the sensors do actually need changing in my case, but it's interesting that many of the errors disappeared when I changed the battery. If it's only two errors, I would suspect it's probably the sensors, if there are lots of errors - it would be worth changing the battery anyway.

I hope this helps.

 

Hi again chumbers, I have change both upstream sensors, but after erase the codes with my reader, they appear again.

So I have 3 options:
- Change the battery.
- Check for bad wirings.
- Install another brand sensors, cause i have installed Bosch ones.

Well...I will open a new threat and try to fix the problems.

 

Hey d_g

This is a difficult one. I can tell you that I have had my x-type for 14 years from brand new... hence, I know it's history etc.

Since having the car, I have had 2 situations previously that have required battery change and neither one brought on the MIL. It malfunctioned in other areas with he occasionally battery light appearing. The battery iight appeared a couple of times during this spell before change the battery which is what also consolidated my decision to change the battery.

If you have changed the sensors for bosch ones, and are confident the bosch ones are compatible, and the errors still read on those sensors - try changing the battery. Only then would I check for bad wiring as this is last potential fault.

I would be interested in hearing how you get on or other peoples thoughts.

S

 

Me too.

In any case I will try today to do the PINPOINT TEST I for the P1646 and the PINPOINT TEST K for the P1647 codes, as the workbook says. Also I will measure the voltage of the battery and the values of the Ohms of the old HO2 sensors to compare...I really need to use the car for a long trip the next week so...I must discover the faults as fast as I can