Jaguar XJ6 (X300) Climate Control Not Working
On the X300 a climate panel that shows Er or beeps at start-up is usually a sensor that was unplugged, with the fault still stored. I'd run the panel's own self-test first: it names the sensor, and many codes are old history that clears for good. A completely dead panel is the module itself; a dark one is bulbs.
How bad is it · Safe to drive
Safe to drive — but check demisting before a wet or cold trip
The engine isn't affected. A dead panel can leave you without demist, so make sure the screen stays clear before setting off.
Which one applies to yours depends on your symptoms, your model year and what has already been done to it.
Likely causes, most common first
Read the check cost before the odds: a free check that rules a cause out beats a likely guess that costs money.
Er and a beep: a sensor unplugged, its fault still stored
The panel logs a fault whenever one of its sensors loses contact: the in-car sensor behind the grille by the driver's knee, the cabin sensor low in the dash, or the outside-air sensor in the left front brake duct. Plugging it back in doesn't wipe the record, so Er and the start-up beep carry on.
Er on the display and a few beeps each time the ignition comes on, often after dash, bumper or undertray work; heating and cooling otherwise behave.
Run the self-test and note the code. Then look for a loose plug behind the lower dash trim on the driver's side and at the left front brake duct.
Reconnect the sensor, clear the stored code from the panel and restart. After bumper work the outside reading can take a drive cycle or two to come back.
Old codes kept from a fault that has gone
The panel remembers up to five codes. Many of them are history — a sensor briefly unplugged, a spell of low gas pressure — and they sit there until someone clears them.
Codes show up in the self-test, yet the heating and cooling work normally.
Write the codes down, clear them, drive for a few days and read them again.
Clear the codes and chase only the ones that return. A code shown together with a beep is a fault that is present right now.
Code 12 and dashes for the outside temperature: the ambient sensor
The outside-air sensor is riveted into the top of the left front brake cooling duct, behind the bumper undertray, on a short lead with a plug. It gets knocked, broken or left unplugged when the bumper or undertray comes off, and its wiring can fail too.
Code 12; the outside temperature shows only dashes or a figure that makes no sense.
Look at the sensor and its plug behind the bumper, then the wiring back from it — not just the sensor itself.
Reconnect or replace the sensor and clear the code. If the code still won't go, it's worth disconnecting the battery for a couple of hours, with the radio code to hand.
Code 24: the centre-vent thumbwheel or its potentiometer
Between the centre dash vents is a thumbwheel with red and blue marks that trims face-vent air against the footwells. Code 24 watches the potentiometer behind it. A wheel left at the cold end can set the code on its own; so can a dirty potentiometer or a vent flap that is slow to move.
Code 24, with no other complaint, or air from the centre vents that won't warm up.
Set the thumbwheel to the middle, clear the code and read again after a few days.
Centre the wheel. If the code comes back, ease the centre vent out — it's a press fit — and clean the potentiometer.
Code 23: the refrigerant pressure switch or a low charge
Code 23 covers the refrigerant pressure switch circuit: gas low, the switch open or shorted, or pressure out of range. In freezing weather, or in great heat, it can log without anything being wrong.
Code 23, usually with weak or warm air from the A/C.
Clear it and see whether it returns in mild weather. If it does, have the pressures checked.
Have the system leak-checked and recharged by an A/C shop; a recharge can bring the cold back much faster.
A completely dead panel: the climate control module
The control module sits behind the panel buttons, and its circuit board can burn. Then no button lights, nothing responds, and the self-test won't even start.
Pressing the power button does nothing at all; no lamps, no display, fans not controlled.
Test the climate fuses live, not by eye, and check the plug on the back of the panel. With the panel plugged in and the ignition on, look for power on the white/blue and white/red wires.
Replace the module. For example, a burnt Denso LNA7600AC was replaced with an LNA7600AF and the panel came back.
A dark or patchy display: the panel bulbs
Two twist-in bulbs light the display, and each button has its own. The display bulbs and the button bulbs are different types, and once one goes the others usually follow.
Part of the panel or the whole display unlit at night while the controls still work.
Take off the ski-slope trim and the frame around the clock, radio and climate panel, then lift the module out to reach the bulbs.
Twist each bulb out a quarter turn and fit new ones: JLM11965 (brown holder) behind the display, JLM20308 (black holder, blue cover) for most buttons, JLM20309 (green cover) for the middle lower one. Handle the module gently, or other bulbs fail.
Code 11: the in-car sensor clogged or unplugged
A tiny fan pulls cabin air over a temperature sensor behind the small louvred grille by the driver's knee. There's no filter, so fluff and dust choke it, and its plug is easily pulled during dash work. The panel then misreads the cabin and heats or cools the wrong way.
Code 11 coming back after clearing; heating that runs too hot or too cold for the setting.
Remove the trim below the steering column and look at the grille, the fan and its plug. On the module's 12-way plug, the signal on pin 33 under 1 V means a short to earth or a lost 5 V feed; about 5 V means an open earth.
Worth trying: clean the grille and fan with a small brush, refit the plug and clear the code.
The order to check them in
The point of the order is money: each step either rules a cause out or makes the next one worth doing. Green is free, amber costs a little, red is the one to arrive at last.
Run the self-test
Warm the engine and switch off. Hold AUTO and RECIRC while turning the ignition on: every lamp on the panel flashes. Press AUTO to show the first code — 0 means none — and step through the rest, up to five, with FACE. A lamp that doesn't flash points at that circuit.
freeRead the code
11 in-car sensor, 12 outside-air sensor, 13 evaporator sensor, 14 coolant signal from the instruments, 15 heater matrix sensor, 21 sun sensor, 22 compressor lock signal, 23 refrigerant pressure switch, 24 face-vent potentiometer, 31 and 32 left and right fresh-air flaps.
freeClear the codes and read again later
In test mode press FACE and the heated rear window button together, once per code; on some cars it's DEMIST with the heated rear window. Press OFF to leave. Read again after a few days of driving.
freeFind the sensor the code names
In-car sensor behind the grille by the driver's knee; outside-air sensor in the left front brake duct; face-vent thumbwheel between the centre vents.
freeDead panel: fuses and the plug behind it
Test the climate fuses live — the numbers are in the fuse block below — then check the connector on the back of the panel before suspecting the module.
a test lampDark panel: change the bulbs
Out with the ski-slope trim, then the module; the bulbs twist out.
a few bulbsThe fuses named above — where they sit
The highlighted position is the one the procedure talks about. Pulling a fuse is a stop-gap, never a repair: check what the circuit feeds before you pull it.
Circuit descriptions from the Jaguar fuse tables, 1995 edition. Drawing by jagaux.com from the factory electrical guide. Fuse layouts change between model years — read the legend on the lid of your own box before pulling anything.
Circuit descriptions from the Jaguar fuse tables, 1995 edition. Drawing by jagaux.com from the factory electrical guide. Fuse layouts change between model years — read the legend on the lid of your own box before pulling anything.
What it usually isn't
Don't spend money here first:
If none of this finds it:
On jagaux.com
- Jaguar XJ6 (X300) Air Conditioning ProblemsIf code 23 keeps coming back and the air isn't cold.
- Jaguar XJ6 (X300) Heater Not WorkingIf the panel works but no heat reaches the cabin.
- Jaguar XJ6 (X300) Instrument Cluster, Dash LightsIf the dash lights fail along with the climate panel lighting.
- XJ6 (X300) fuse boxes and relaysClimate fuses for 1995 cars; 1996 and 1997 from the same page.
- Jaguar VIN decoderConfirm your exact model year, engine and factory options before ordering parts — free.
Ratings, fuse numbers and torque figures vary by model year and market. Read the legend on your own car before pulling anything, and use the figures in the manual for your car, not the ones in a video.
Check your VIN: exactly which car you have and which bulletins apply to it.