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Morning all

I recently took my 2007 XJ-R in for a gearbox oil change following advice from the Forum (thank you – works a treat now), but received a quite alarming Diagnostics Report when it came back. I’ve looked up the individual faults, but as there are so many I’m wondering if there is something causing all these faults to appear?

There is nothing wrong with anything as far as I can tell – the only indicators are the alarm going off intermittently (seems to be the bonnet) and the engine warning light is on. The only other recent change since the report was a new radiator.

I’d be grateful for any feedback on the best next steps please!

Here we go:

Engine Control Module
P0420-00

Transmission Control Module
P0730
P0736

Antilocking Brake System
C1109-64

Air Suspension Control Module
B1671
U2521

Electronic Parking Brake
B1318-00

Driver Door Module
B1676
B1895

General Electronics Control Module
B2496
B2493
B2491

Instrument Pack and Panel Illumination
U2515
U2521
U2197
U2200
U2150
U2152
B1875
B2139

Rear Electronics Control Module
U1262
B2162
B2533
B2565
B2577
B2370
C1755
B1676
U3FF6

Drivers Seat Module
B1940

Dual Climate Seat Module
B1154-98

Adaptive Speed Control
U0433

There are also a number of ‘Modules Not Fitted or Not Communicating:
TPMS – I don’t think I have this, but I think I would have the following: Auxiliary Heater Control Module, Rear Seat Module, Steering Column Lock Module, Intrusion Sensor Control Module.

Your help would be greatly appreciated!

David

Panic not. There is a cause which just has to be found. Often it can be a simple fault or even just an issue caused by a glitch which has left a pile of historic electronic "scorch marks" on the ecu. The number of codes you have present implies that a glitch has taken place.

Firstly, how old is the battery? With age comes an unstable battery voltage condition which can cause the OBD diagnostic program to fail to complete. The cheapo range of replacement batteries are not worth considering. Use only premium grade batteries from Bosch or Varta as replacements. Have a battery voltage drop test performed to confirm battery condition under load.

Firstly, check and clean up ground bonding cables behind the head lights. There is as I recall also another near the brake servo. Also have a look at the bonding points in the spare wheel well.

Try disconnecting the battery for at least twenty minutes. This is known as a hard dump and will clear historic fault codes which sometimes fail to be cleared by even an SDD or IDS dealer level diagnostic program and kit. Ensure you have the radio reset code to hand before you do this. Also charge the battery over night with a mains charger. Reconnect the battery, deal with the radio and reset the clock. Then start up and see if the check light, MIL lamp and any message centre legend is extinguished. Do this and the issues may disappear.

Come back to us again and let us know how you got on.

A good solid high grade battery is essential on these cars. Terminal voltage should be at full charge level of 12.8v. 12.4v is a half discharged battery and 12v or less implies a well discharged battery that is possibly at the end of its useful reliable life.

Mike K

Hi Mike - many thanks for the reply and the advice, it's what I was hoping I might get told!! As for the battery, I had a new one replaced mid last year by the RAC when my old one died on me - they said it would be suitable, but I will get it checked as it's under warranty.

I'll try the 'dump' method and check those terminals ASAP!!

Many thanks

David

Hi - I nearly forgot to post an update on this one before I head off to Suspension with another issue!!

My local, friendly, priced-right mechanic had a look for me and managed to clear the faults, identifying the engine management light being a lambda sensor. I took a long run-out and it cleared, so fingers crossed all is well!

Regards

David

(see you in Suspension!)

A bottle of Cataclean in a quarter of a tank of fuel might assist the Lamda sensors. They could have become a bit fouled. Cataclean is very effective around the cats and sensors.

Drive fairly gently whilst the additive is in the tank and do a good run out to get the exhaust hot. Several of us have used the product and have found it surprisingly effective. I regard it as preventative maintenance in a bottle and give the car an annual dose.

Mike