light BMW 7 SERIES 1985 E23 Cruise Control
Page 5 of 14
Test at ECU Plug
Component/Circuit
Result
4. Ignition on—check volt-
age at Terminal #5.
Control switch RESUME.
Move lever to RESUME.
Voltage jumps 0 to 12V.
If not, check wiring and
switch.
5. Measure resistance Term-
inal #3 to ground. (Auto
transmission in neutral.)
(Ignition off.)
A.) Automatic Trans-
mission
B.) Manual Trans-
mission
A.) Approximately 4
B.) < 1
6. Apply voltage to term.
#8 and ground term. #9.
Actuator solenoid
(Clutch)
Listen for click in actuator
7. Measure resistance
Terminal #8 to ground.
Actuator and clutch
switch.
Resistance approx. 30
Press clutch pedal, then
resistance = oo
If not, check wiring, clutch
switch, and brake lights.
8. Apply voltage to term.
#13 and ground term. #25.
Actuator motor
Listen for motor running.
9. Measure resistance
Terminal #24 to Terminal
#23.
Actuator potentiometer.
Resistance approx. 3000
If not, check wiring/
replace actuator.
10. Measure resistance
Terminal #23 to ground.
Ground
Resistance = 0
If not, check wiring and
ground.
11. Measure resistance
Terminal #26 to ground.
Actuator.
Resistance approx. 3000
If not, check wiring/
replace actuator.
12. Measure voltage at
term. #9 (Ignition on)
Brake light switch
0 Volts then depress brake
pedal voltage = 12V.
61-09/3
Page 6 of 14
FOR CRUISE CONTROL TO BE ENGAGED
PIN 9 MUST SENSE GROUND THROUGH
STOPLIGHTS.
WHEN BRAKE SWITCH IS CLOSED OR
CLUTCH SWITCH IS OPEN, GROUND IS
ELECTRONICALLY REMOVED.
CRUISE CONTROL ELECTRICAL SCHEMATIC
BRAKE
SWITCH
CLOSED WITH BRAKE
PEDAL DEPRESSED
POWER
DISTRIBUTION
BOX
CLUTCH
SWITCH
OPENS WHEN
CLUTCH PEDAL
IS DEPRESSED
POWER
DISTRIBUTION
BOX
AUTOMATIC
TRANSMISSION
RANGE SWITCH
AUTOMATIC TRANSMISSION
CRUISE
CONTROL
SWITCH
C210
CRUISE CONTROL
CONTROL UNIT
TRANSMISSION
RANGE
DISPLAY
TO THROTTLE
VALVE
FEEDBACK
POTENTIOMETER
INSTRUMENT
CLUSTER
CRUISE
CONTROL
ACTUATOR
CLUTCH
SOLENOID
CANCEL RESUME ACCELERATE/
SPEED SET SPEED
CONTROL INPUTS
INSTRUMENT
CLUSTER
MANUAL
TRANSMISSION
IDLE
SPEED
CONTROL
FUSE 6
8 AMP
POWER
DISTRIBUTION
POWER
DISTRIBUTION
ACCELERATE/
SET
OFF RESUME
OFF
S217 C206 S309 C301
.75 GN/WT
.5 VI/WT C210 GN/WT
CLUTCH CONTROL CONTROL MOTOR CRUISE
OUTPUT OUTPUT ENABLE
SEE DASH LIGHTS
GROUND
"N"
OUTPUT
BAND
1.5 GN/WT
1 GN/WT
11
1 GN/WT
.75 GN/WT
.75 GN/WT
1
.75 8U/3R
.75 BU/BR
S234
3
15
1
2
D
6
N
R
P
S
W
0
GN
BU
.5 YL
.5 GN
.5 BU
4
5
SPEEDOMETER
SOLID STATE
2
C8
.5 BU/YL
CRUISE CONTROL
CONTROL UNIT
POWER INPUT
.5 VI/WT
C250
STOP LIGHTS
.5 GN/RD
.5 GN/RD
MANUAL
TRANSMISSION
AUTOMATIC
TRANSMISSION
C208
.5 GN/RD
C208
61-09/5
S224
.5 GN/RD
.5 GN/RD
9
G200
.5 BR
SPEEDOMETER
.5 VI/WT
1.5 VI/WT
S241
FUSE 12
8 AMP
.5 VI/WT
VEHICLE SPEED
INPUT
CRUISE
ENABLE
.75
BU/BR
C8
GROUND
FEEDBACK
REFERENCE
FEEDBACK
INPUT
SOLID STATE
24
26
.5 GY/RD
.5 GN/YL
4
.5 RD
7
.5 YL
.5 BR
3
S233
(-)
12
16
C1
C6
.5 BR
.5 BR
G200
.5 BR
.75 BU/BR
6
7
.75 BU/BR
.5 BU
C209
.5 BU/WT
2
3
G200
13
.5 BK
5
.5 BK
.5 GN
.5 WT
.5 WT
CONTROL
MOTOR
1
Page 11 of 14
CRUISE CONTROL ELECTRICAL SCHEMATIC 733IA
61-08/3
GN-green BR-brown
WS-white RT-red
BL-blue VI-violet
GE-yellow
1. Control Unit (ECU) 5. Adaptor 9. Fuses
2. Reed Switch 6. Trans. Lights (Instruments) 10. Relief Relay
3. Servo 7. Brake Switch 11. Ignition Switch
4. Control Switch 8. Brake Light 12. Battery
Page 13 of 14
CRUISE CONTROL ELECTRICAL SCHEMATIC 633CSiA
61-08/5
1. Control Unit (ECU) 5. Control Switch 9. Fuses
2. Signal Generator 6. Battery 10. Relief Relay
3. Ignition Switch 7. Adaptor 11. Brake Light
4. Servo 8. Trans. Lights 12. Brake Switch
GN-green BR-brown
WS-white RT-red
BL-blue VI-violet
GE-yellow