PINPOINT TEST B: DTC B1251 OR DTC1253 — A/C IN-VEHICLE TEMPERATURE SENSOR OPEN CIRCUIT OR SHORT TO GROUND
Is the resistance greater than 10,000 ohms?
A17 CHECK CIRCUITS 436 (RD/LG) AND 437 (YE/LG) FOR A SHORT TO GROUND
Disconnect: Temperature Blend Door Actuator C289.
Measure the resistance between RCC module C228 pin 5, circuit 436 (RD/LG) and ground. Measure the
resistance between RCC module C228 pin 9, circuit 437 (YE/LG) and ground.
Are the resistances greater than 10,000 ohms?
Yes
GO to
A18
.
No
REPAIR the affected circuit for a short to ground. TEST
the system for normal operation.
A18 CHECK CIRCUITS 436 (RD/LG), 437 (YE/LG) AND 438 (RD/WH) FOR A SHORT TO POWER
Ignition ON.
Measure the voltage between RCC module C228 pin 5, circuit 436 (RD/LG), RCC module C228 pin 9, circuit
437 (YE/LG) and RCC module C228 pin 20, circuit 438 (RD/WH) and ground.
Is voltage present?
Yes
REPAIR the affected circuit for a short to power. TEST the
system for normal operation.
No
INSPECT for a broken door or linkage. If no condition is
found, INSTALL a new RCC module. REFER to
Section
412-04
. TEST the system for normal operation.
Test Step
Result / Action to Take
B1 CHECK THE SENSOR RESISTANCE
Ignition OFF.
Disconnect: In-Vehicle Temperature Sensor C233.
Measure the resistance between the in-vehicle temperature sensor terminals.
Is the resistance within the specified values for these temperature ranges: 10-20°C (50-68°F), 37,000-58,000
ohms; 20-30°C (68-86°F), 24,000-37,000 ohms; 30-40°C (86-104°F), 16,000-24,000 ohms?
Yes
GO to
B2
.
No
INSTALL a new in-vehicle temperature sensor.
TEST the system for normal operation.
B2 CHECK THE REMOTE CLIMATE CONTROL (RCC) MODULE OUTPUT VOLTAGE
Ignition ON.
Press the AUTOMATIC button.
Measure the voltage between the in-vehicle temperature sensor C233, circuit 790 (WH/OG) and circuit 470 (PK/BK).
Yes
INSTALL a new RCC module. TEST the system
for normal operation.
No
If diagnosing DTC B1251, GO to
B3
. If
diagnosing DTC B1253, GO to
B5
.
Page 12 of 47
2003 Taurus/Sable Workshop Manual
11/22/2011
http://www.fordtechservice.dealerconnection.com/pubs/content/~WS3H/~MUS~LEN/19/...
