Pinpoint Test F: DTC B1A63 Or DTC B1A64
Climate Control System
Pinpoint Tests
Pinpoint Test F: DTC B1A63 or DTC B1A64
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 from the HVAC module through circuit RH107 (GN/BU). A 5-volt reference voltage is supplied to the sunload sensor from the HVAC module through circuits VH417 (YE/OG) (RH) and VH416 (VT/GY) (LH).
B1A63:11-B1A64:15:
This pinpoint test is intended to diagnose the following:
- Wiring, terminals or connectors
- A/C sunload sensor
- HVAC module
PINPOINT TEST F: DTC B1A63 OR DTC B1A64
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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 RH107 (GN/BU), harness side and sunload sensor:
- For DTC B1A63, C286-1, circuit VH417 (YE/OG), harness side.
- For DTC B1A64,C286-3, circuit VH416 (VT/GY), harness side.
- Is the voltage between 4.7 and 5.1 volts?
Yes
INSTALL a new sunload sensor. CLEAR the DTCs. REPEAT the self-test. If the code returns, GO to F7.
No
If diagnosing DTC B1A63:15 or DTC B1A64:15, GO to F2.
If diagnosing DTC B1A63:11 or DTC B1A64:11, GO to F5.
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F2 CHECK CIRCUITS VH416 (VT/GY) AND VH417 (YE/OG) FOR A SHORT TO VOLTAGE
- Ignition OFF.
- Disconnect: HVAC Module C228a/C2356a.
- Disconnect: HVAC Module C228b/C2356b.
- Ignition ON.
- Measure the voltage between ground and sunload sensor:
- For DTC B1A64:11, C286-3, circuit VH416 (VT/GY), harness side.
- For DTC B1A63:11, C286-1, circuit VH417 (YE/OG), harness side.
- Is any voltage present?
Yes
REPAIR circuit VH416 (VT/GY) or VH417 (YE/OG) for a short to voltage. CLEAR the DTCs. REPEAT the self-test. TEST the system for normal operation.
No
GO to F3.
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F3 CHECK CIRCUIT RH107 (GN/BU) FOR AN OPEN
- Ignition OFF.
- Measure the resistance between sunload sensor C286-4, circuit RH107 (GN/BU), harness side and HVAC module C228a/C2356a-10, circuit RH107 (GN/BU), harness side.
- Is the resistance less than 5 ohms?
Yes
GO to F4.
No
REPAIR circuit RH107 (GN/BU) for an open. CLEAR the DTCs. REPEAT the self-test. TEST the system for normal operation.
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F4 CHECK CIRCUIT VH417 (YE/OG) OR VH416 (VT/GY) FOR AN OPEN
DTC B1A64:15
- NOTE: For DTC B1A64:15.
- Measure the resistance between HVAC module C228b/C2356b-6, circuit VH416 (VT/GY), harness side and sunload sensor C286-3, circuit VH416 (VT/GY), harness side.
DTC B1A63:15
- NOTE: For DTC B1A63:15.
- Measure the resistance between HVAC module C228b/C2356b-3, circuit VH417 (YE/OG), harness side and sunload sensor C286-1, circuit VH417 (YE/OG), harness side.
- Is the resistance less than 5 ohms?
Yes
GO to F7.
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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F5 CHECK CIRCUIT VH417 (YE/OG) OR VH416 (VT/GY) FOR A SHORT TO CIRCUIT RH107 (GN/BU)
- Ignition OFF.
- Disconnect: HVAC Module C228a/C2356a.
- Disconnect: HVAC Module C228b/C2356b.
- Measure the resistance between sunload sensor C286-4, circuit RH107 (GN/BU), harness side and sunload sensor:
- For DTC B1A64:11, C286-3, circuit VH416 (VT/GY), harness side.
- For DTC B1A63:11, C286-1, circuit VH417 (YE/OG), harness side.
- Is the resistance greater than 10,000 ohms?
Yes
GO to F6.
No
REPAIR circuit VH417 (YE/OG) or VH416 (VT/GY) for a short to circuit RH107 (GN/BU). CLEAR the DTCs. REPEAT the self-test. TEST the system for normal operation.
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F6 CHECK CIRCUIT VH416 (VT/GY) OR VH417 (YE/OG) FOR A SHORT TO GROUND
- Measure the resistance between ground and sunload sensor:
- For DTC B1A64:11, C286-3, circuit VH416 (VT/GY), harness side.
- For DTC B1A63:11, C286-1, circuit VH417 (YE/OG), harness side.
- Is the resistance greater than 10,000 ohms?
Yes
GO to F7.
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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F7 CHECK THE MODULE CONNECTION
- Carry out the HVAC Module Cold Boot Process. HVAC Module Cold Boot Process
- Carry out the HVAC Module On-Demand Self Test. Alternate Diagnostic Methods - HVAC Module
- 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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