Volvo 850. Manual - part 63

Fig. 12:  Identifying A/C Relay Connector Terminals

Courtesy of Volvo Cars of North America.

Fig. 13:  Removing Damper Motor

Courtesy of Volvo Cars of North America.

         DTC 2-1-2, 2-2-2, 2-3-2, 2-3-4 & 2-3-6 DRIVER’S OR

         PASSENGER’S SIDE DAMPER MOTOR POSITION SENSOR

         SHORTED TO GROUND

         1) Check if DTCs 2-1-2, 2-2-2, 2-3-2, 2-3-4, and 2-3-6 are

all present together. If all DTCs are not present, there is a short

circuit in ground wire between ECC control unit and damper motor which

applies to DTC. See AUTOMATIC A/C-HEATER SYSTEM DIAGNOSTIC TROUBLE

CODES table, then go to next step. If all DTCs are present, an open

circuit is present in common voltage circuit at ECC terminal A8. See

Fig. 10.

         2) Ensure ignition is off. Connect test unit between ECC

control module and control unit connector. Check ECC grounds. See DTC

1-2-1, OUTSIDE TEMP. SENSOR CIRCUIT SHORTED TO GROUND. Also check

power supply to damper motor position sensor. See  TEST MODE 2 under

TROUBLE SHOOTING. If ECC grounds and power supply to damper motor

position sensor are okay, go to next step.

         3) Turn ignition off. Disconnect ECC control module, but

leave test unit connected to ECC control module connector. Disconnect

6-pin damper motor connector. See Figs. 11-13. Connect ohmmeter

between test unit pin No. 10 and pin indicated in  DAMPER MOTOR TEST

UNIT PIN NUMBERS (RESISTANCE CHECK) table.

DAMPER MOTOR TEST UNIT PIN NUMBERS (RESISTANCE CHECK)

Pin No.                                         Damper Motor

10 & 17  ....................................  Driver’s Side

10 & 18  .................................  Passenger’s Side

10 & 20  ......................................  Ventilation

10 & 19  ....................................  Floor/Defrost

10 & 21  ....................................  Recirculation

         4) If ohmmeter indicates continuity, short circuit is present

in wiring at terminal No. 3. If ohmmeter indicates no continuity,

wiring is okay. Go to next step.

         5) Ensure ignition is off. Disconnect damper motor connector.

Connect ohmmeter between damper motor terminals No. 1 and 3. See

Fig. 11. Turn damper motor output shaft. Ohmmeter reading should vary

between 0-12,000 ohms.

         6) If resistance is to specification, check voltage supply

circuit between motor connector terminal No. 2 and ECC control module

terminal A8. If resistance is a constant zero ohms, a short is present

in damper motor position sensor. Replace damper motor.

         DTC 3-1-1, 3-1-2, 3-1-3, 3-1-4 & 3-1-5 DAMPER MOTOR SHORTED

         TO GROUND OR POWER

         1) Turn ignition off. Connect test unit between ECC control

module and ECC control module connector. Check system 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. Connect one voltmeter lead to test unit

pin No. 10 and other lead to test unit pin No. 31 (driver’s damper

motor), No. 33 (passenger’s side damper motor), No. 37 (ventilation

damper motor), No. 35 (floor/defrost damper motor), or No. 39

(recirculation damper motor). Voltmeter should vary from 0-4 volts.

         3) If voltmeter indicates zero volts, wire is shorted to

ground. If voltmeter indicates battery voltage, wire is shorted to

voltage. Turn ignition off. Disconnect suspect damper motor connector.

Check wiring between motor connector and ECC control module.

         DTC 3-2-1, 3-2-2, 3-2-3, 3-2-4 & 3-2-5

         DAMPER MOTOR ACTIVE TOO LONG

         1) Check if DTCs 3-2-1, 3-2-2, 3-2-3, 3-2-4, and 3-2-5 are

also present. If all DTCs are present, vehicle may be equipped with an

ECC control module for a right-hand-drive vehicle, or vice versa.

Check ECC terminal A28. See Fig. 10. ECC control module for left-hand-

drive vehicles should not have terminal A28 grounded.

         2) If terminal is okay, perform self-adjustment of damper

motor limit positions under TEST MODE 4. If motor limit positions are

adjusted correctly, check ECC system ground circuits. See DTC 1-2-1,

OUTSIDE TEMP. SENSOR CIRCUIT SHORTED TO GROUND. If ground circuits

check okay, go to next step.

         3) Ensure test unit is connected to ECC control module. Turn

ignition on. Connect one voltmeter lead to test unit pin No. 10 and

other lead to test unit pin No. 31 (driver’s side damper motor), No.

33 (passenger’s side damper motor), No. 37 (ventilation damper motor),

No. 35 (floor/defrost damper motor), or No. 39 (recirculation damper

motor).

         4) Rotate air circulation knob to and from different settings

while observing voltmeter. Voltmeter should show control voltage of

about 0-12 volts while damper is moving to its new setting. If

voltmeter shows about 0-12 volts for longer than about 12 seconds,

check if damper is stuck in position. Replace damper if not stuck.

         DTC 4-1-1 PASSENGER COMPARTMENT FAN OVERCURRENT OR SEIZED FAN

         1) Turn ignition off. Disconnect passenger compartment

(blower) fan electrical connector. Check if fan turns freely by hand.

If fan does not turn freely, replace fan. Check fan location for

anything that could cause blockage and clear as necessary.

         2) If fan is okay, erase DTC. If DTC returns, there may be a

fault in power stage surge protector. See DTC 4-1-9, ECC POWER STAGE

EMITTING FAULTY DIAGNOSTIC SIGNAL.

         DTC 4-1-2 & 4-1-5 DRIVER’S OR PASSENGER’S SIDE TEMP.

         SENSOR INTAKE FAN SHORTED TO GROUND

         1) Ensure ignition is off. 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, turn ignition

off. Disconnect test unit from ECC control module, but leave it

connected to ECC control module connector. Disconnect passenger

compartment temperature sensor connector.

         2) Check driver’s side fan by connecting an ohmmeter between

test unit pins No. 6 and 45. Check passenger’s side fan by connecting

an ohmmeter between test unit pins No. 6 and 46. If ohmmeter indicates

continuity, wiring is shorted to ground or voltage. If ohmmeter

indicates no continuity, wiring is okay.

         3) Ensure ignition is off. Disconnect passenger compartment

temperature sensor connector. Connect an ohmmeter between passenger

compartment temperature sensor connector terminals No. 2 and 4. See

Fig. 6. Ohmmeter should indicate about 50,000 ohms. If ohmmeter

indicates continuity, intake fan is shorted. Replace fan and

temperature sensor.

         DTC 4-1-3 & 4-1-6 DRIVER’S OR PASSENGER’S SIDE TEMP.

         SENSOR INTAKE FAN, NO CONTROL VOLTAGE

         1) Ensure ignition is off. 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) Ensure ignition is off. Disconnect test unit from ECC

control module, but leave it connected to ECC control module