Pinpoint Test B: DTC B1A61:11 and 15
Climate Control System
Pinpoint Test B: DTC B1A61:11 and 15
Refer to Wiring Diagram Set 55, Automatic Climate Control System for schematic and connector information. [1][2]Diagrams By Number
Normal Operation
Under normal operation, the in-vehicle air temperature sensor receives a ground from the HVAC module through circuit RH111 (GY/BU). A 5-volt reference voltage is supplied to the in-vehicle air temperature sensor from the HVAC module through circuit VH414 (GN/BU).
- DTC B1A61:11 (Cabin Temperature Sensor: Circuit Short to Ground)- The module senses excessive voltage drop on the sensor reference voltage circuit, indicating a short directly to ground.
- DTC B1A61:15 (Cabin Temperature Sensor: Circuit Short to Battery or Open)- The module senses no voltage drop on the sensor reference voltage circuit, indicating a short directly to voltage or an open circuit.
This pinpoint test is intended to diagnose the following:
- Wiring, terminals or connectors
- In-vehicle air temperature sensor
- HVAC module
PINPOINT TEST B : DTC B1A61:11 AND 15
B1 CHECK THE SENSOR RESISTANCE
- Ignition OFF.
- Disconnect: In-Vehicle Temperature/Humidity Sensor C2247.
- Measure the resistance between the in-vehicle temperature/humidity sensor C2247-2, component side and C2247-5, component side and compare to the table below.
Ambient Temperature Resistance -40°C (-40°F) 862,600-942,000 ohms -15°C (5°F) 202,400-214,700 ohms 0°C (32°F) 93,510-97,640 ohms 15°C (59°F) 46,060-47,430 ohms 25°C (77°F) 29,700-30,300 ohms 35°C (95°F) 19,400-20,000 ohms 60°C (140°F) 7,414-7,774 ohms 85°C (185°F) 3,182-3,393 ohms
Is the resistance within the specified values for the temperatures?
Yes
GO to B2.
No
INSTALL a new in-vehicle temperature/humidity sensor. CLEAR the DTCs. REPEAT the self-test. TEST the system for normal operation.
B2 CHECK THE SENSOR OUTPUT VOLTAGE
- Ignition ON.
- Measure the voltage between in-vehicle temperature/humidity sensor C2247-2, circuit VH414 (GN/BU), harness side and C2247-5, circuit RH111 (GY/BU), harness side.
Is the voltage between 4.7 and 5.1 volts?
Yes
INSTALL a new in-vehicle temperature/humidity sensor. CLEAR the DTCs. REPEAT the self-test. If code returns, GO to B8.
No
For DTC B1A68:15, GO to B3.
For DTC B1A68:11, GO to B6.
B3 CHECK CIRCUIT VH414 (GN/BU) FOR A SHORT TO VOLTAGE
- Ignition OFF.
- Disconnect: HVAC Module- Dual Automatic Temperature Control (DATC) C2356a.
- Disconnect: HVAC Module- DATC (Dual Automatic Temperature Control) C2356b.
- Ignition ON.
- Measure the voltage between ground and HVAC module- DATC (Dual Automatic Temperature Control) C2356B-21, circuit VH414 (GN/BU), harness side.
Is any voltage present?
Yes
REPAIR circuit VH414 (GN/BU) for a short to voltage. CLEAR the DTCs. REPEAT the self-test. TEST the system for normal operation.
No
GO to B4.
B4 CHECK CIRCUIT VH414 (GN/BU) FOR AN OPEN
- Ignition OFF.
- Measure the resistance between HVAC module- DATC (Dual Automatic Temperature Control) C2356B-21, circuit VH414 (GN/BU), harness side and in-vehicle temperature/humidity sensor C2247-2, circuit VH414 (GN/BU), harness side.
Is the resistance less than 5 ohms?
Yes
GO to B5.
No
REPAIR circuit VH414 (GN/BU) for an open. CLEAR the DTCs. REPEAT the self-test. TEST the system for normal operation.
B5 CHECK CIRCUIT RH111 (GY/BU) FOR AN OPEN
- Measure the resistance between HVAC module C2356A-10, circuit RH111 (GY/BU), harness side and in-vehicle temperature/humidity sensor C2247-5, circuit RH111 (GY/BU), harness side.
Is the resistance less than 5 ohms?
Yes
GO to B8.
No
REPAIR circuit RH111 (GY/BU) for an open. CLEAR the DTCs. REPEAT the self-test. TEST the system for normal operation.
B6 CHECK CIRCUIT VH414 (GN/BU) FOR A SHORT TO CIRCUIT RH111 (GY/BU)
- Ignition OFF.
- Disconnect: HVAC Module- DATC (Dual Automatic Temperature Control) C2356b.
- Measure the resistance between in-vehicle temperature/humidity sensor C2247-2, circuit VH414 (GN/BU), harness side and C2247-5, circuit RH111 (GY/BU), harness side.
Is the resistance greater than 10,000 ohms?
Yes
GO to B7.
No
REPAIR circuit VH414 (GN/BU) for a short to circuit RH111 (GY/BU). CLEAR the DTCs. REPEAT the self-test. TEST the system for normal operation.
B7 CHECK CIRCUIT VH414 (GN/BU) FOR A SHORT TO GROUND
- Measure the resistance between HVAC module- DATC (Dual Automatic Temperature Control) C2356B-21, circuit VH414 (GN/BU), harness side and ground.
Is the resistance greater than 10,000 ohms?
Yes
GO to B8.
No
REPAIR circuit VH414 (GN/BU) for a short to ground. CLEAR the DTCs. REPEAT the self-test. TEST the system for normal operation.
B8 CHECK THE MODULE CONNECTION
- Inspect the module connectors for:
- corrosion.
- pushed-out terminals.
- damaged terminals.
- Connect and correctly seat all the HVAC module connectors.
- Clear the DTCs.
- Operate the system and verify the concern is still present.
Is the concern still present?
Yes
INSTALL a new HVAC module. TEST the system for normal operation.
No
The system is operating correctly at this time. The concern may have been caused by a loose or corroded connector. CLEAR the DTCs. REPEAT the self-test. TEST the system for normal operation.