LR3/Disco 3
Automatic Temperature Control (ATC) Module - C1629
drive
setting
available
available
5
Blower motor
voltage sense
Voltage variation observed
as blower motor setting
changes
None
999C
Information not
available
Input
Information not
available
6
Cavity not used n/a
n/a
n/a
n/a
n/a
n/a
7
Cavity not used n/a
n/a
n/a
n/a
n/a
n/a
8
Cavity not used n/a
n/a
n/a
n/a
n/a
n/a
9
Sensor ground Information not available
B1B8115 None
Rear A/C doesn't
get cold
Output
Open circuit
10
Rear blower
relay coil drive
0V to switch rear blower
relay on when rear A/C is
on
None
99A2
Information not
available
Output
Information not
available
11
Solenoid valve
drive
0V to switch valve on when
rear A/C is on
None
99A2
Information not
available
Output
Information not
available
12
Evaporator
temperature
sensor signal
Resistance at 25° is 1.5k
ohms. Pull up resistance is
5.62k ohms
B1B8111 999B
Lack of cooling
from rear A/C
Input
Short circuit to
ground
12
Evaporator
temperature
sensor signal
Resistance at 25° is 1.5k
ohms. Pull up resistance is
5.62k ohms
B1B8115 999B
Lack of cooling
from rear A/C
Input
Open circuit
Cavity
Description
Typical Condition -
No fault
DTC
PID
Symptom
Input/Output
Possible
Cause
1
Sensor 5V
supply
5V ± 0.25V (C2655-
13)
B1A5911
9969
A/C system does
not cool cabin
Input
Open circuit,
short circuit to
ground
2
Pollution sensor
Nox signal -
Japanese
specification
vehicles only
0.4V to 4.7V, rises
in a Nox pollution
event
B1B6211
99A9
Inlet flap does not
close in response
to pollution event.
May lead to bad air
quality in cabin
Input
Short circuit to
ground
3
In-vehicle
temperature
sensor signal
1.7k ohms. Pull up
resistance 4.4k
ohms at 25°C
B1A6115
9927
Poor cabin
temperature control
Input
Open circuit,
short circuit to
12V
3
In-vehicle
temperature
sensor signal
1.7k ohms. Pull up
resistance 4.4k
ohms at 25°C
B1A6111
9927
Poor cabin
temperature control
Input
Short circuit to
ground
4
Refrigerant
pressure sensor
signal
0.5V at zero
pressure rising to
4.8V at
approximately
3.2MPa when 5V
seen at C2655-1
B1A6215
9990
Compressor not
running, no cooling
available
Input
Open circuit,
short circuit to
12V
