Pinpoint Test E: DTCs B1A68:11 and 15
Climate Control System
Pinpoint Test E: DTCs B1A68:11 and 15
Refer to Wiring Diagram Set 54, Manual Climate Control System for schematic and connector information. [1][2]Diagrams By Number
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 ambient air temperature sensor receives a ground from the HVAC module through circuit RH111 (GY/BU). A 5-volt reference voltage is supplied to the ambient air temperature sensor from the HVAC module through circuit VH407 (YE/GN).
- DTC B1A68:11 (Ambient 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 B1A68:15 (Ambient 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
- Ambient air temperature sensor
- HVAC module
PINPOINT TEST E : DTCs B1A68:11 AND 15
E1 CHECK THE SENSOR RESISTANCE
- Ignition OFF.
- Disconnect: Ambient Air Temperature Sensor C132.
- Measure the resistance between the ambient air temperature sensor C132 terminals and compare to the table below.
Ambient Temperature Resistance -40°C (-40°F) 832,519-1,017,523 ohms -15°C (5°F) 199,325-220,307 ohms 0°C (32°F) 91,058-100,644 ohms 15°C (59°F) 44,435-49,113 ohms 25°C (77°F) 28,500-31,500 ohms 35°C (95°F) 18,730-20,701 ohms 60°C (140°F) 7,171-7,925 ohms 85°C (185°F) 3,110-3,438 ohms
Is the resistance within the specified values for the temperatures?
Yes
GO to E2.
No
INSTALL a new ambient air temperature sensor. CLEAR the DTCs. REPEAT the self-test. TEST the system for normal operation.
E2 CHECK THE SENSOR OUTPUT VOLTAGE
- Ignition ON.
- Measure the voltage between ambient air temperature sensor C132-1, circuit VH407 (YE/GN), harness side and C132-2, circuit RH111 (GY/BU), harness side.
Is the voltage between 4.7 and 5.1 volts?
Yes
INSTALL a new ambient air temperature sensor. CLEAR the DTCs. REPEAT the self-test. If code returns, GO to E8.
No
For DTC B1A61:15, GO to E3.
For DTC B1A61:11, GO to E6.
E3 CHECK CIRCUIT VH407 (YE/GN) FOR A SHORT TO VOLTAGE
- Ignition OFF.
- Disconnect: HVAC Module- Electronic Manual Temperature Control (EMTC) C2357a.
- Disconnect: HVAC Module- Dual Automatic Temperature Control (DATC) C2356a.
- Ignition ON.
- Measure the voltage between HVAC module- DATC (Dual Automatic Temperature Control) C2356A-2, circuit VH407 (YE/GN), harness side and ground.
Is any voltage present?
Yes
REPAIR circuit VH407 (YE/GN) for a short to ground. CLEAR the DTCs. REPEAT the self-test. TEST the system for normal operation.
No
GO to E4.
E4 CHECK CIRCUIT VH407 (YE/GN) FOR AN OPEN
- Ignition OFF.
- Measure the resistance between HVAC module- DATC (Dual Automatic Temperature Control) C2356A-2, circuit VH407 (YE/GN), harness side and ambient air temperature sensor C132-1, circuit VH407 (YE/GN), harness side.
Is the resistance less than 5 ohms?
Yes
GO to E5.
No
REPAIR circuit VH407 (YE/GN) for an open. CLEAR the DTCs. REPEAT the self-test. TEST the system for normal operation.
E5 CHECK CIRCUIT RH111 (GY/BU) FOR AN OPEN
- Measure the resistance between HVAC module- DATC (Dual Automatic Temperature Control) C2356A-10, circuit RH111 (GY/BU), harness side and ambient air temperature sensor C132-2, circuit RH111 (GY/BU), harness side.
Is the resistance less than 5 ohms?
Yes
GO to E8.
No
REPAIR circuit RH111 (GY/BU) for an open. CLEAR the DTCs. REPEAT the self-test. TEST the system for normal operation.
E6 CHECK CIRCUIT VH407 (YE/GN) FOR A SHORT TO CIRCUIT RH111 (GY/BU)
- Ignition OFF.
- Disconnect: HVAC Module- EMTC (Electronic Manual Temperature Control) C2357a.
- Disconnect: HVAC Module- DATC (Dual Automatic Temperature Control) C2356a.
- Measure the resistance between ambient air temperature sensor C132-1, circuit VH407 (YE/GN), harness side and C132-2, circuit RH111 (GY/BU), harness side.
Is the resistance greater than 10,000 ohms?
Yes
GO to E7.
No
REPAIR circuit VH407 (YE/GN) for a short to circuit RH111 (GY/BU). CLEAR the DTCs. REPEAT the self-test. TEST the system for normal operation.
E7 CHECK CIRCUIT VH407 (YE/GN) FOR A SHORT TO GROUND
- Measure the resistance between HVAC module- DATC (Dual Automatic Temperature Control) C2356A-2, circuit VH407 (YE/GN), harness side and ground.
Is the resistance greater than 10,000 ohms?
Yes
GO to E8.
No
REPAIR circuit VH407 (YE/GN) for a short to ground. CLEAR the DTCs. REPEAT the self-test. TEST the system for normal operation.
E8 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.