B1A69:15

Climate Control System

Pinpoint Test C: DTC B1A69:11 or 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 temperature/humidity sensor is grounded through circuit RH111 (GY/BU). A 5-volt reference voltage is supplied to the in-vehicle temperature/humidity sensor from the HVAC module through circuit LH111 (BN/WH). The HVAC module receives the humidity value through circuit VH413 (WH/BU).

- DTC B1A61:11 (Humidity 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 (Humidity 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 temperature/humidity sensor

- HVAC module

PINPOINT TEST C : DTC B1A69:11 OR 15

C1 CHECK THE SENSOR OUTPUT VOLTAGE

- Ignition OFF.

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

- Ignition ON.

- Measure the voltage between in-vehicle temperature/humidity sensor C2247-4, circuit VH413 (WH/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 C7.

No

For DTC B1A69:15, GO to C2.

For DTC B1A69:11, GO to C5.

C2 CHECK CIRCUIT VH413 (WH/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-20, circuit VH413 (WH/BU), harness side.





Is any voltage present?

Yes
REPAIR circuit VH413 (WH/BU) for a short to voltage. CLEAR the DTCs. REPEAT the self-test. TEST the system for normal operation.

No
GO to C3.

C3 CHECK CIRCUIT VH413 (WH/BU) FOR AN OPEN

- Ignition OFF.

- Measure the resistance between HVAC module- DATC (Dual Automatic Temperature Control) C2356B-20, circuit VH413 (WH/BU), harness side and in-vehicle temperature/humidity sensor C2247-4, circuit VH413 (WH/BU), harness side.





Is the resistance less than 5 ohms?

Yes
GO to C4.

No
REPAIR circuit VH413 (WH/BU) for an open. CLEAR the DTCs. REPEAT the self-test. TEST the system for normal operation.

C4 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 C7.

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

C5 CHECK CIRCUIT VH413 (WH/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 C2247-4, circuit VH413 (WH/BU), harness side and C2247-5, circuit RH111 (GY/BU), harness side.





Is the resistance greater than 10,000 ohms?

Yes
GO to C6.

No
REPAIR circuit VH413 (WH/BU) for a short to circuit RH111 (GY/BU). CLEAR the DTCs. REPEAT the self-test. TEST the system for normal operation.

C6 CHECK CIRCUIT VH413 (WH/BU) FOR A SHORT TO GROUND

- Measure the resistance between HVAC module- DATC (Dual Automatic Temperature Control) C2356B-20, circuit VH413 (WH/BU), harness side and ground.





Is the resistance greater than 10,000 ohms?

Yes
GO to C7.

No
REPAIR circuit VH413 (WH/BU) for a short to ground. CLEAR the DTCs. REPEAT the self-test. TEST the system for normal operation.

C7 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.