2010 JAGUAR XFR ignition coil

control switch on the integrated control panel or the + and - soft buttons on the touch screen display (TSD). The ATC module also adjusts blower speed to compensate for the ram effect on inlet air produced by forward movement of the vehicle. As
vehicle speed and ram effect increases, blower motor speed is reduced, and vice versa.

Air Distribution Control

Two air distribution doors are used to direct air into the passenger compartment. The doors are operated by stepper motors,
which are controlled by the ATC module using LIN bus messages.
When the A/C system is in automatic mode, the ATC module automatically controls air distribution into the passenger compartment in line with its 'comfort' algorithm. Automatic control is overridden if any of the TSD air distribution soft buttons
are selected. Air distribution in the passenger compartment will remain as selected until the 'Auto' switch is pressed or a
different manual selection is made.

A/C Compressor Control

When A/C is selected the ATC module maintains the evaporator at an operating temperature that varies with the passenger compartment cooling requirements. If the requirement for cooled air decreases, the ATC module raises the evaporator operating temperature by reducing the flow of refrigerant provided by the A/C compressor. The ATC module closely controls the rate of temperature increase to avoid introducing moisture into the passenger compartment.

If the requirement for cooled air increases, the ATC module lowers the evaporator operating temperature by increasing the flow of refrigerant provided by the A/C compressor.
When A/C is off, the compressor current signal supplied by the ATC module holds the A/C compressor solenoid valve in the minimum flow position, effectively switching off the A/C function.
The ATC module incorporates limits for the operating pressure of the refrigerant system. If the system approaches the high pressure limit, the compressor current signal is progressively reduced until the system pressure decreases. If the system falls
below the low pressure limit, the compressor current signal is held at its lowest setting so that the A/C compressor is maintained at its minimum stroke. This avoids depletion of the lubricant from the A/C compressor.
A/C Compressor Torque

The ATC module transmits refrigerant pressure and A/C compressor current values to the ECM (engine control module) over the medium speed then high speed CAN bus, using the CJB as a gateway. The ECM uses these values to calculate the torque being used to drive the A/C compressor. The ECM compares the calculated value with its allowable value and if necessary forces the ATC module to inhibit the A/C compressor by transmitting the 'ACClutchInhibit' CAN message. This forces the ATC module to reduce the drive current to the A/C compressor solenoid valve, which reduces refrigerant flow. This in turn reduces the torque required to drive the A/C compressor.
By reducing the maximum A/C compressor torque, the ECM is able to reduce the load on the engine when it needs to maintain vehicle performance or cooling system integrity.

Cooling Fan Control

The ATC module determines the amount of condenser cooling required from the refrigerant pressure sensor, since there is a direct relationship between the temperature and pressure of the refrigerant. The cooling requirement is broadcast to the ECM on the medium speed CAN bus. The ECM then controls the temperature of the condenser using the cooling fan.
Programmed Defrost

The programmed defrost DEF switch is located on the integrated control panel. When the switch is pressed, the ATC module instigates the programmed defrost function. When selected, the ATC module configures the system as follows:
Automatic mode off.
A/C on. Selected temperature unchanged.
Air inlet set to fresh air.
Air distribution set to windshield.
Blower speed set to level 6.
Windshield heater (where fitted) and rear window heater on.
The programmed defrost function can be cancelled by one of the following:
Selecting any air distribution switch on the TSD.
Pressing the AUTO switch on the integrated control panel.
A second press of the DEF button.
Switching the ignition OFF.
The blower speed can be adjusted without terminating the programmed defrost function.

Rear Window Heater

Rear window heater operation is only enabled when the engine is running. The ATC module controls operation of the rear window heater using a relay in the RJB. When rear window heater operation is required, the ATC module broadcasts a message to the RJB on the medium speed CAN bus. On receipt of the message, the RJB energizes the relay by providing a ground path for the relay coil. This allows a battery feed to flow across the relay to power the rear window heater element.

Check the Starter Relay circuit.


NOTE: On petrol engine variants, due to Smart Start, both sides of Relay Coil are switched directly from ECM (If
conditions correct). On diesel engine variants the low side only is switched directly from the ECM.
Check that the Steering Column Lock correctly operates and the steering wheel can turn freely.

Check that the High Speed CAN network is not malfunctioning, i.e. the CAN circuit is open or short circuit. This would mean
that the instrument cluster and ECM would be unable to communicate resulting in no Challenge being performed to enable the
ECM. This would be supported by LED Flash Code 24, see PATS Fault Code Table.

Also check the CAN network between the ABS module and the CJB. The CJB uses the CAN_BrakePressureTMC signal to
determine if the brake pedal has been pressed in order to allow an engine crank. The CJB uses a value of 0x05, if the CJB sees
a value less than this, it will not enable the Crank Request Output.
Engine cranks but will not start

If the Engine is cranking it means that the ECM has passed the authorisation required with the Instrument Cluster. If this
authorisation failed, the ECM would not engage the starter relay. This could be confirmed by verifying the PATS LED prove out
(illuminated solid for 3 seconds) or by reading DTCs from the instrument cluster and ECM.

In this case, the fuel pump circuit should be verified. The Fuel Pump Delivery Module (FPDM), which is supplied via the RJB
(authentication required with the instrument cluster) and controlled by the ECM, supplies the fuel pump.
In all cases of suspected non-start issues, the most logical failure modes should be eliminated first. i.e.

1. Check all relevant supplies and grounds to the relevant modules listed herein.
2. Note any unusual behaviour from other systems/functionality.
3. Note any functions that are not operating as expected.
PATS Fault Codes

For the various PATS modes/faults listed in the table , the instrument cluster will store a DTC and indicate this to the customer
during the detection period defined in the 'when logged' column, by illuminating the indicator as described for 60 seconds and
then flashing the LED 10 times as appropriate. The indication will stop immediately the ignition status is set to OFF any time
during the fault indication sequence. Up to 4 DTCs could be stored per key read sequence (1-10 read attempts). No DTCs will be
stored until all retry attempts are complete. Only the highest priority fault code will be flashed.

To determine the fault code from the LED: The LED will flash initially ten times with 1.5 seconds between. The LED will remain
OFF for 2.5 seconds then flash a number of times with 0.5 seconds between (the number of times the LED flashes represents
the first digit of the code), the LED will remain OFF for 1.5 seconds then flash a number of times with 1.5 seconds between
(the number of times the LED flashes represents the second digit of the code).

The PATS LED will be commanded on as shown under 'indication'. Normal PATS operations are complete within 400ms of the
ignition switch transition from OFF to ON or START, worst case for ECM communication problems will be less than 2 seconds. If
PATS is not complete during the 2 seconds the ECM will terminate PATS and await the next ignition ON or START event. PATS
faults will be indicated via the LED as soon as possible and will terminate the LED prove out. At ignition OFF all previous
flashing will cease and the perimeter anti-theft system will control the LED when the vehicle is locked and armed.

PATS Fault Code Table


Mode of Operation/Fault

When Logged
Ignition
Status

DTC LED
Fault
Code

Indication Prove out N/A Transition
from OFF to
ON N/A N/A
3 Seconds of steady
illumination Perimeter Anti-theft Control N/A OFF -
Vehicle
locked and
armed N/A N/A
Off or 0.5Hz flashing
at 5% duty cycle ±
20% until Off Start Control Unit already programmed Key Insert Any B1B0105 N/A No Indication Start Control Unit status = invalid response Key Insert Any B1B0167 N/A No Indication Start Control Unit programming error Key Insert Any B1B0151 N/A No Indication Start Control Unit challenge response error Key Insert OFF B1B0162 N/A No Indication Key Programming timer expired or Key Auth Timer expired Key Insert Any B1B0187 N/A No Indication Transponder challenge response error Key Insert Any B1B0164 N/A No Indication Transponder keys stored below minimum number required B&A/Dealer Any B1B0100 N/A No Indication Transponder not programmed B&A/Dealer Any B1B0155 N/A No Indication If the instrument cluster sends a 'theft' key status
to the ECM or the ECM returns a status message
containing the data 'Disabled/Theft', the instrument
cluster will set this DTC EMS CAN
communication OFF to ON B1B3364 16
60 seconds of 4Hz
flashing at 50% duty
cycle followed by fault
code 16 flashing 10
times