SSM75173

Special Service Message
NOTE: A Special Service Message is a formal communication issued by Jaguar and carries the
same importance of a Technical Service Bulletin. An SSM is a quick method of communicating
"Need To Know" information to the technical service community. SSM's may be issued in advance
of a technical bulletin or may be the only communication on a given topic. All information
contained in Jaguar technical communications are intended for use by trained, professional
technicians with the knowledge, tools, and equipment required to complete the procedure
correctly and safely. It informs the Technicians of conditions that may occur on some vehicles, or
provides information that could assist in correct vehicle and diagnostic service.
SSM 75173 - Air Conditioning operating
Intermittently. (PHEV – Electric AC Compressor
only)
Models : E-Pace / X540
F-Pace / X761
Engineer :Shilvock Matthew
Date Last 08 DEC 2020 12:46:29
Updated :
Content :X761 PHEV – 21MY
X540 PHEV 21MY
Note:
This failure mode can manifest intermittently. Correct diagnosis using the
detailed procedure below can only be achieved when the vehicle / Air
Conditioning system is inoperative.
Issue:
Electric Air Conditioning compressor can be inhibited as designed by a Low
System Power Inhibit. This will cause Air Conditioning to operate intermittently
causing no cabin cooling.
Cause:
The Low System Power Inhibit is set by the Vehicle Supervisory Controller (VSC)
which is part of the Powertrain Control Module (PCM). The Inhibit is set when
there is less than or equal to 500 watts of power available to the Climate
System. Climate Power will be cut resulting in the Electric Air Conditioning
compressor being disabled. This is not a climate control issue and the fault will
lie in another system.
Action:
Carry out an Autoscan DTC read with Pathfinder and check for any associated
DTC’s stored and refer to TOPIx. In particular HVAC module, PCM and all High
Voltage modules. If a DTC is stored in HVAC then please refer to TOPIx and
repair. If there are NO DTC’s stored in HVAC module then please proceed to
carry out the following Live data reads.
Live Data DID Reads 9A51 – Electric AC Compressor Inhibits
9801 – AC Compressor Run In Status
988B – Climate Hybrid Component Status
98E1 – AC Compressor Inlet Pressure
9990 – AC System Pressure
Check results of DID 9A51 for any listed Electric AC Compressor Inhibits as
shown below. If an Inhibit is shown as YES for Low System Power (See picture
attached) then the issue is not HVAC and will require further diagnosis
& investigation.
Important Note:
The Low System Power inhibit will not be present when Air Conditioning is
functional and operating correctly. When the Air Conditioning is in a failed
state, the Electric Air Conditioning Compressor has been disabled due to Low
System Power available and there is no Cabin Cooling the Low System Power
inhibit MAY then be present and display YES as shown above.
When Live Data readings have been recorded, please create a .pdf file, raise a
TA and attach the pdf to the TA documenting tests that have been conducted.
Diagnostic Procedure:
CAUTION: This procedure requires a minimum of Pathfinder version 305 or
later.
NOTE:
The Jaguar Land Rover (JLR) approved diagnostic equipment will read the
Vehicle Identification Number (VIN) for the vehicle and automatically take
the vehicle out of ‘Transportation mode’ if required.
Procedure:
1. Connect the JLR approved battery support unit.
2. Connect the JLR approved diagnostic equipment to the vehicle and
begin a new session.
Follow the JLR approved diagnostic equipment prompts.
3.
Replicate FAILED STATE with Air Conditioning inoperative.
4.
Engine running in Power Mode 7 and ‘READY’ displayed in instrument
cluster.
5.
Select ‘MAX AC’ on climate control panel.
6.
Select ‘ECU Diagnostic’
7.
Select ‘HVAC Control Module (HVAC)’
8.
Select ‘Live Data’
9.
Select the following ‘DID’s’
9A51 – Electric AC Compressor Inhibits
9801 – AC Compressor Run In Status
988B – Climate Hybrid Component Status
98E1 – AC Compressor Inlet Pressure
9990 – AC System Pressure
10. Create pdf file
11. When all of the tasks are complete, exit the session.
12. Disconnect the JLR approved diagnostic equipment and the
JLR approved battery support unit.
13. Raise Technical Assist (TA)
A Technical Assistance (TA) should be submitted to Local Technical Support
(LTS) documenting all of the above checks and results also attaching the pdf
file of the DID results.
Version : 1
Attachments : Low System Power Inhibit.pdf
Jaguar Land Rover Limited 2000 - 2020 (Rel. 2685)