SSM75559

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 75559 - AJ20-P4 engine – Coolant leak from Thermostat
Models : E-Pace / X540
F-Pace / X761
F-Type / X152
XE / X760
XF / X260
Engineer Shilvock Matthew
Name :
Last 20 OCT 2021 16:46:11
Modified :
Category : Driveline
Symptom : 510000 Fluid Concerns
Content : I s s u e: JLR is investigating AJ20-P4 thermostats with
complaints for coolant leaks (on any vehicle) that are
coming into service with evident leak or with low
coolant MIL warning [sometimes associated with P0128
DTC]
C a u s e s: JLR investigation in progress
Action: If you see this issue present on a vehicle, and if
you suspect the coolant leak is from the thermostat
A. Gross leak from thermostat
1 . Screenshot of the latest DTCs / warning light
2 . Share video evidence of fresh leak
3 . Check if the housing is sitting properly – refer
image (A) attached. If there are signs of incorrect
assembly, replace the thermostat with a new
4 . If no issue found in step (3), document evidence of
location and reason for gross leak and replace the
part with a new one
B. Evident fresh leak [not gross] from thermostat.
1 . Screenshot of the latest DTCs / warning light
2 . Share video evidence of fresh leak
3 . Clean the fresh leak thoroughly and also ensure
the grooves do not hold any residual coolant
4 . Test drive the car for about 30 minutes and check
for leak again
5 . If there is a leak, provide video evidence of the
leak and proceed with replacing the part with a
new one.
6 . If there is no leak, perform the standard cooling
system pressure test and show evidence that leak
is observed in thermostat
7 . If the pressure test does not confirm leak on the
thermostat, do not change the thermostat. Check
rest of the coolant circuit for leak
C. No evident fresh leak but only dried up coolant
deposit is seen on the body of the thermostat [Image B]
1 . Screenshot of the latest DTCs / warning light
2 . Confirm if there was any external coolant spill
[either at dealer end or customer end]
3 . Check the coolant pipes on top of / around the
thermostats for any leak / damage [pipes which
has possibility of leaking coolant to the
thermostat body]
4 . Clean the thermostat surface and the suspect leak
location thoroughly [without removing thermostat
from the engine]
5 . Make sure the grooves do not contain any residual
coolant.
6 . Test drive the car for about 30 minutes and
inspect the thermostat again for any fresh leak
7 . If there is no leak, perform the standard cooling
system pressure test and show evidence that leak
is observed in thermostat
8 . If the pressure test does not confirm leak on the
thermostat, do not change the thermostat. Check
rest of the coolant circuit for leak
NOTES:
If the car comes in for repeat failure, perform the
same checks as above. But replace the part with a
new one and prepare the removed part for return
to Engineer.
Thermostats as a whole is a serviceable part. So,
do not manipulate the thermostats in anyway.
If P0128 DTC Is present, first perform actions as
per TOPIX against the DTC prior to performing the
actions in SSM.
Thank you for your assistance with this matter.
File : AJ20-P4 engine – Coolant leak from Thermostat.pdf
Jaguar Land Rover Limited 2000 - 2021 (Rel. 2693)