Volvo 850. Manual — part 65

2

Digital Timer (Parking Heater)

12 Volts (On);

0 Volts (Off)

3

Rheostat

12 Volts (On);

0 Volts (Off)

5

Power Supply To Power Stage

Battery Voltage

6

Power Ground

0 Volts

8

Damper Motor Position Sensors

5 Volts

9

Signal Ground

0 Volts

10

Signal Ground

0 Volts

12

Driver’s Side Temp. Sensor

About 2.5 Volts

At Room

Temperature

13

Passenger’s Side Temp. Sensor

About 2.5 Volts

At Room

Temperature

14

Outside Temperature Sensor

About 2.5 Volts

At Room

Temperature

17

Driver’s Side Damper Motor Position

About 0.5-5.0

Sensor

Volts

18

Passenger’s Side Damper Motor Position

About 0.5-5.0

Sensor

Volts

19

Floor/Defrost Damper Motor Position

About 0.5-5.0

Sensor

Volts

20

Ventilation Damper Motor Position

About 0.5-5.0

Sensor

Volts

21

Recirculation Damper Motor Position

About 0.5-5.0

Sensor

Volts

23

Engine Coolant Temperature

5 Volts (Square

Wave) Variable

Frequency

24

Vehicle Speed Signal

12 Volts (Square

Wave) Variable

Frequency

25

A/C Relay Control Signal (From

0-2 Volts (On);

Ignition System)

About 12 Volts

(Off)

27

Diagnostic Signal From Power Stage

3 Volts (Normal);

4 Volts

(Overcurrent);

1 Volt (No

Signal)

28

Logic Signal

Open (Left);

0 Volts (Right)

30

Signal To/From Diagnostic Unit

Battery Voltage

(1) - Pin assignments not listed are not used.

ECC CONTROL MODULE PIN ASSIGNMENTS CONNECTOR "B"

(1)

Function/Description

Voltage Value

Pin No.

31

Driver’s Side Damper

About 0.4 Volts (Off), Zero Volts

Motor Positive

Or Battery Voltage (On With

Control Signal

Control)

32

Driver’s Side Damper

About 0.4 Volts (Off), Zero Volts

Motor Negative Control

Or Battery Voltage (On With

Signal

Control)

33

Passenger Side Damper

About 0.4 Volts (Off), Zero Volts

Motor Positive Control

Or Battery Voltage (On With

Signal

Control)

34

Passenger Side Damper

About 0.4 Volts (Off), Zero Volts

Motor Negative Control

Or Battery Voltage (On With

Signal

Control)

35

Floor/Defrost Damper

About 0.4 Volts (Off), Zero Volts

Motor Positive Control

Or Battery Voltage (On With

Signal

Control)

36

Floor/Defrost Damper

About 0.4 Volts (Off), Zero Volts

Motor Negative Control

Or Battery Voltage (On With

Signal

Control)

37

Ventilation Damper

About 0.4 Volts (Off), Zero Volts

Motor Positive Control

Or Battery Voltage (On With

Signal

Control)

38

Ventilation Damper

About 0.4 Volts (Off), Zero Volts

Motor Negative Control

Or Battery Voltage (On With

Signal

Control)

39

Recirculation Damper

About 0.4 Volts (Off), Zero Volts

Motor Positive Control

Or Battery Voltage (On With

Signal

Control)

40

Recirculation Damper

About 0.4 Volts (Off), Zero Volts

Motor Negative Control

Or Battery Voltage (On With

Signal

Control)

41

Control Signal To A/C

About 0 Volts Or Battery Voltage

Relay

42

Control Signal To Power

12 Volts (Square Wave) Constant

Stage

Frequency With Varying Duty Cycle

45

Driver’s Side Passenger

0 Volts Or Battery Voltage Temp.

Compartment

Sensor Intake Fan Control Signal

46

Passenger’s Side

0 Volts Or Battery Voltage Temp.

Passenger Compartment

Sensor Intake Fan Control Signal

(1) - Pin assignments not listed are not used.

ECC CONTROL MODULE PIN ASSIGNMENTS CONNECTOR "C"

(1)

Function/Description

Voltage Value

Pin No.

47

Driver’s Side Duct Temp.

About 2.5 Volts At Room

Sensor Signal

Temperature

48

Passenger’s Side Duct Temp.

About 2.5 Volts At Room

Sensor Signal

Temperature

51

Signal From Solar Sensor

2-40 Millivolts

56

Signal Ground

0 Volts

(1) - Pin assignments not listed are not used.

SOLAR SENSOR

1) Connect test unit to ECC control module. Check ground

circuits. See DTC 1-2-1, OUTSIDE TEMP. SENSOR CIRCUIT SHORTED TO

GROUND. If ground circuits are okay, go to next step.

2) Turn ignition on. Aim a light source at solar sensor.

Connect voltmeter between test unit pins No. 51 and 56 and record

voltage. Cover solar sensor and read voltage again. See Fig. 16.

Voltage should vary by a few millivolts. The higher the intensity, the

lower the voltage. If sensor does not operate as specified, there is

an open circuit or short to ground in wire or solar sensor.

Fig. 16: Locating ECC System Sensors

Courtesy of Volvo Cars of North America.

SPEEDOMETER SIGNAL

1) Raise and support front of vehicle. Perform TEST MODE 2

under TROUBLE SHOOTING. ECC control module should respond to vehicle

speed signal with Code 1-1-3. ECC control module will continue to

flash code even once TEST MODE 2 is activated. If Code 1-1-3 does not

appear, turn ignition off. Cover solar sensor. Turn ignition on. Start

TEST MODE 2. Let car wheels turn freely. Open throttle.

2) If no acknowledgment code appears after several attempts,

there may be a problem with vehicle speed signal impulse sensor in

ignition system, instrument panel, or wiring.

3) Check if speedometer operates. If speedometer does not

operate, a fault may be present in vehicle speed signal impulse

sensor, ignition system, instrument cluster, or wiring. If speedometer

does operate, check for open circuit in instrument cluster wiring.

REMOVAL & INSTALLATION

WARNING: To avoid injury from accidental air bag deployment, read and

carefully follow all SERVICE PRECAUTIONS and DISABLING &

ACTIVATING AIR BAG SYSTEM procedures in the AIR BAG RESTRAINT

SYSTEM article in the ACCESSORIES/SAFETY EQUIPMENT section.

A/C RELAY & POWER STAGE

Removal & Installation

Turn ignition off. The A/C relay and power stage are located

on A/C climate control unit, behind glove compartment. Remove glove

compartment. Remove A/C relay. Disconnect connector from power stage.

Hold catches in and pull connector straight out from power stage. See

Fig. 15. To install, reverse removal procedure.

CLIMATE CONTROL UNIT

Removal & Installation

1) Disconnect negative battery cable. Remove dashboard

assembly. See DASHBOARD. Discharge A/C system, using approved

refrigerant recovery/recycling equipment. Disconnect evaporator inlet

and outlet pipes, and cap both ends. Remove evaporator cover plate and

gasket from firewall. See Fig. 17.

2) Disconnect heater hose quick-disconnect couplings. Remove

heater hose cover plate and gasket from firewall. Inside vehicle,

disconnect A/C-heater control cables and all electrical connectors

from climate control unit. Remove relay shelf. See Fig. 15.

3) Remove tunnel console. Remove kick panels next to tunnel.

Remove rear floor ducts connection hose. Remove radio amplifier

bracket. Disconnect cruise control vacuum cylinder, if equipped.

Remove climate control unit. To install, reverse removal procedure.

Lubricate NEW "O" rings with compressor oil. Evacuate and charge

system.