Pinpoint Test F: DTC B2426, B2427, B2795 or DTC B2796
Climate Control System
Pinpoint Tests
Pinpoint Test F: DTC B2426, B2427, B2795 or DTC B2796
Refer to Wiring Diagram Set 55, Automatic Climate Control System for schematic and connector information. Diagrams By Number
Normal Operation
Under normal operation, the sunload sensor receives a ground through circuit GD116 (BK/VT). A 5-volt reference voltage is supplied to the sunload sensor from the HVAC module - Electronic Automatic Temperature Control (EATC) or HVAC module - Dual Automatic Temperature Control (DATC) through circuits (LH) VH416 (VT/GY) and (RH) VH417 (YE/OG).
B2426-B2796:
This pinpoint test is intended to diagnose the following:
- Wiring, terminals or connectors
- Sunload sensor
- HVAC module - EATC
- HVAC module - DATC
PINPOINT TEST F: DTC B2426, B2427, B2795 or DTC B2796
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F1 CHECK THE SUNLOAD SENSOR REFERENCE VOLTAGE
- Ignition OFF.
- Disconnect: Sunload Sensor C286.
- Ignition ON.
- Press the AUTO button.
- Measure the voltage between sunload sensor C286-4, circuit GD116 (BK/VT), harness side and:
- For DTC B2426 or B2427, C286-1, circuit VH417 (YE/OG), harness side.
- For DTC B2795 or B2796, C286-3, circuit VH416 (VT/GY), harness side.
- Are the voltages between 4.7 and 5.1 volts?
Yes
INSTALL a new sunload sensor. CLEAR the DTCs. REPEAT the self-test. If the DTC returns, GO to F5.
No
If diagnosing DTC B2426 or B2796, GO to F2.
If diagnosing DTC B2427 or B2795, GO to F4.
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F2 CHECK CIRCUIT GD116 (BK/VT) FOR AN OPEN
- Ignition OFF.
- Measure the resistance between sunload sensor C286-4, circuit GD116 (BK/VT), harness side and ground.
- Is the resistance less than 5 ohms?
Yes
GO to F3.
No
REPAIR circuit GD116 (BK/VT) for an open. CLEAR the DTCs. REPEAT the self-test. TEST the system for normal operation.
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F3 CHECK CIRCUIT VH416 (VT/GY) OR VH417 (YE/OG) FOR AN OPEN
- Disconnect: HVAC Module - DATC C2356b or HVAC Module - EATC C228b.
EATC
- NOTE: EATC systems only.
- Measure the resistance between HVAC module - EATC C228b-18, circuit VH416 (VT/GY), harness side and sunload sensor C286-3, circuit VH416 (VT/GY), harness side.
DATC, DTC B2426
- NOTE: DATC systems only.
- Measure the resistance between HVAC module - DATC C2356b-5, circuit VH417 (YE/OG), harness side and sunload sensor C286-1, circuit VH417 (YE/OG), harness side.
DATC, DTC B2796
- NOTE: DATC systems only.
- Measure the resistance between HVAC module - DATC C2356b-18, circuit VH416 (VT/GY), harness side and sunload sensor C286-3, circuit VH416 (VT/GY), harness side.
- Is the resistance less than 5 ohms?
Yes
GO to F5.
No
REPAIR circuit VH416 (VT/GY) or VH417 (YE/OG) for an open. CLEAR the DTCs. REPEAT the self-test. TEST the system for normal operation.
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F4 CHECK CIRCUIT VH416 (VT/GY) OR VH417 (YE/OG) FOR A SHORT TO GROUND
- Ignition OFF.
- Disconnect: HVAC Module - DATC C2356b or HVAC Module - EATC C228b.
- Measure the resistance between ground and:
- For DTC B2427, sunload sensor C286-1, circuit VH417 (YE/OG), harness side.
- For DTC B2795, sunload sensor C286-3, circuit VH416 (VT/GY), harness side.
- Are the resistances greater than 10,000 ohms?
Yes
GO to F5.
No
REPAIR circuit VH416 (VT/GY) or VH417 (YE/OG) for a short to ground. CLEAR the DTCs. REPEAT the self-test. TEST the system for normal operation.
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F5 CHECK THE MODULE CONNECTION
- Carry out the HVAC Module Cold Boot Process. HVAC Module Cold Boot Process
- Carry out the HVAC Module - Electronic Automatic Temperature Control (EATC) and HVAC Module - Dual Automatic Temperature Control (DATC) On-Demand Self Test.
- Operate the system.
- Does the concern return?
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.
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