Discovery II
ENGINE MANAGEMENT SYSTEM - V8
DESCRIPTION AND OPERATION
18-2-9
Pin out details connector C0634
Connector 2 (C0635): This connector contains 24 pins and is primarily used for Heated Oxygen Sensors (HO
2
S)
control and earth. The HO
2
S sensors require a heater circuit to assist in heating the tip of the sensors to enable closed
loop fuelling to be implemented quickly after cold starting.
Pin out details connector C0635
Pin No.
Function
Signal type
Reading
1
Ignition position II
Input
12 V
2
Not used
-
-
3
Not used
-
-
4
Chassis earth
Earth
0V
5
Fuel injectors earth
Earth
0V
6
Power stage earth
Earth
0V
7
Permanent battery supply
Input battery supply
12V
8
Switched relay positive
Input switched
0-12V
9
Not used
-
-
Pin No.
Function
Signal type
Reading
1
HO
2
S heater RH bank - downstream
Output
PWM 12-0V
2
Not used
-
-
3
Not used
-
-
4
Not used
-
-
5
Thermostat monitoring sensor
Earth
0V
6
Not used
-
-
7
HO
2
S heater LH bank - downstream
Output
PWM 12-0V
8
HO
2
S sensor RH bank - downstream
Earth/ Signal
0V
9
HO
2
S sensor LH bank - upstream
Earth/ Signal
0V
10
HO
2
S sensor RH bank - upstream
Earth/ Signal
0V
11
HO
2
S sensor LH bank - downstream
Earth/ Signal
0V
12
Not used
-
-
13
HO
2
S heater RH bank - upstream
Output
PWM 12-0V
14
HO
2
S sensor RH bank - downstream
Input/ Signal
Analogue 0-5V
15
HO
2
S sensor LH bank - upstream
Input/ Signal
Analogue 0-5V
16
HO
2
S sensor RH bank - upstream
Input/ Signal
Analogue 0-5V
17
HO
2
S sensor LH bank - downstream
Input/ Signal
Analogue 0-5V
18
Fuel pump relay
Output
Switch to earth
19
HO
2
S heater LH bank - upstream
Output
PWM 12-0V
20
Not used
-
-
21
Thermostat monitoring sensor
Signal
Analogue 0-5V
22
Not used
-
-
23
Main relay
Output
Switch to earth
24
EVAP system leak detection pump motor (NAS
vehicles with positive pressure type, EVAP system
leak detection capability only)
Output
Switch to earth
