Pinpoint Test D: DTCs B1A61:11 and 15

Climate Control System

Pinpoint Test D: DTCs B1A61:11 and 15

Refer to Wiring Diagram Set 55, Automatic Climate Control System for schematic and connector information Electrical Diagrams.

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 D : DTCs B1A61:11 AND 15

D1 CHECK THE SENSOR RESISTANCE

- Ignition OFF.

- Disconnect: In-Vehicle Temperature/Humidity Sensor C2247.

- Measure the resistance between in-vehicle temperature/humidity sensor C2247 terminals 1 and 3.





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 D2.

No
INSTALL a new in-vehicle temperature/humidity sensor. CLEAR the DTCs. REPEAT the self-test. TEST the system for normal operation.

D2 CHECK THE SENSOR OUTPUT VOLTAGE

- Ignition ON.

- Measure the voltage between in-vehicle temperature/humidity sensor C2247-1, circuit VH414 (GN/BU), harness side and C2247-3, 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 D8.

No

For DTC B1A61:15, GO to D3.

For DTC B1A61:11, GO to D6.

D3 CHECK CIRCUIT VH414 (GN/BU) FOR A SHORT TO VOLTAGE

- Ignition OFF.

- Disconnect: HVAC Module C2356A.

- Disconnect: HVAC Module C2356B.

- Ignition ON.

- Measure the voltage between ground and HVAC module 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 D4.

D4 CHECK CIRCUIT VH414 (GN/BU) FOR AN OPEN

- Ignition OFF.

- Measure the resistance between HVAC module C2356B-21, circuit VH414 (GN/BU), harness side and in-vehicle temperature sensor C2247-1, circuit VH414 (GN/BU), harness side.





Is the resistance less than 5 ohms?

Yes
GO to D5.

No
REPAIR circuit VH414 (GN/BU) for an open. CLEAR the DTCs. REPEAT the self-test. TEST the system for normal operation.

D5 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 sensor C2247-3, circuit RH111 (GY/BU), harness side.





Is the resistance less than 5 ohms?

Yes
GO to D8.

No
REPAIR circuit RH111 (GY/BU) for an open. CLEAR the DTCs. REPEAT the self-test. TEST the system for normal operation.

D6 CHECK CIRCUIT VH414 (GN/BU) FOR A SHORT TO CIRCUIT RH111 (GY/BU)

- Ignition OFF.

- Disconnect: HVAC Module C2356B.

- Measure the resistance between in-vehicle temperature sensor C2247-1, circuit VH414 (GN/BU), harness side and C2247-3, circuit RH111 (GY/BU), harness side.





Is the resistance greater than 10,000 ohms?

Yes
GO to D7.

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.

D7 CHECK CIRCUIT VH414 (GN/BU) FOR A SHORT TO GROUND

- Measure the resistance between HVAC module C2356B-21, circuit VH414 (GN/BU), harness side and ground.





Is the resistance greater than 10,000 ohms?

Yes
GO to D8.

No
REPAIR circuit VH414 (GN/BU) for a short to ground. CLEAR the DTCs. REPEAT the self-test. TEST the system for normal operation.

D8 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.