Volvo 850 Supplement Manual page 11

DTC 1-2-2 OUTSIDE TEMP. SENSOR CIRCUIT OPEN OR SHORTED TO
POWER
1) Ensure DTCs 1-2-2, 1-2-4, 1-2-6, 2-1-1, 2-2-1, 2-3-1, 2-3-
3 or 2-3-5 are not present at the same time. If any of these codes are
present at the same time, check for an open circuit in the common
ground wire. If only DTC 1-2-2 is present, go to next step.
2) Turn ignition off. Install test unit and adapter between
ECC control module and harness connector. Using ohmmeter, connect test
leads between ground and test unit pins No. 6, 9, 10 and 56. Ohmmeter
should read zero ohms in each terminal. If resistance is as specified,
go to next step. If resistance is not as specified, check for open
circuit.
3) Turn ignition on. Connect voltmeter between test unit pins
No. 10 and 14. Check voltage to outside temperature sensor. Voltage
should be about 2.6 volts at 68
volts, check for open in circuit or in outside temperature sensor. If
voltage reading is 12 volts, check for open in circuit between sensor
harness terminal No. 1 and ECC control module.
4) Turn ignition off. Disconnect Adapter (981 3194) from ECC
control module. Disconnect outside temperature sensor connector
(located on right rear of engine compartment). See Figs. 4 and 5.
Install jumper wire between sensor harness terminals. Connect ohmmeter
between test unit pins No. 10 and 14. If ohmmeter reads zero ohms,
wire is okay. Check for faulty sensor. If ohmmeter reads infinity,
sensor is okay. Check for open circuit.
DTC 1-2-3 & 1-2-5 DRIVER'S OR PASSENGER'S SIDE TEMP.
SENSOR CIRCUIT SHORTED TO GROUND
1) Turn ignition off. Install test unit and adapter between
ECC control module and harness connector. Using ohmmeter, connect test
leads between ground and test unit pins No. 6, 9, 10 and 56. Ohmmeter
should read zero ohms in each terminal. If resistance is as specified,
go to next step. If resistance is not as specified, check for open
circuit.
2) Disconnect adapter from ECC control module. Disconnect
appropriate side temperature sensor connector. See Figs. 6 and 7.
Connect ohmmeter to test unit pins No. 10 and 12 to check driver's
side temperature sensor and terminals No. 10 and 13 to check
passenger's side temperature sensor.
3) If ohmmeter reads zero ohms, check for short circuit
between driver's or passenger's side temperature sensor and ECC
control module. See WIRING DIAGRAMS.
4) To check driver's or passenger's side temperature sensor,
ensure harness connector from sensor is disconnected. Connect ohmmeter
between temperature sensor terminal No. 3 (Brown wire) and terminal
No. 5 (Green or Yellow wire). Resistance should be 8000-12,000 ohms.
If resistance is not as specified, replace faulty temperature sensor.
Fig. 6: Identifying Passenger Compartment Temperature Sensor
Connector & Component Terminals
Courtesy of Volvo Cars of North America.
£ £
F (20 C). If voltage reading is 5