Pinpoint Test W: The Auxiliary Temperature, Panel/Floor And Blower Motor Controls Are Inoperative/Do Not Operate Correctly Usin
Climate Control System
Pinpoint Tests
Pinpoint Test W: The Auxiliary Temperature, Panel/Floor and Blower Motor Controls are Inoperative/Do Not Operate Correctly Using the Front/Rear Auxiliary Climate Controls
Refer to Wiring Diagram Set 52, Auxiliary Climate Control for schematic and connector information. Diagrams By Number
Normal Operation
Under normal operation, the panel/floor and cool/warm signal is received by the HVAC module - Dual Automatic Temperature Control (DATC) from the rear auxiliary control through circuit VHA15 (YE/GY). The blower speed signal is received by the HVAC module - DATC from the rear auxiliary control through circuit VHA17 (VT/GN). Reference voltage for the auxiliary controls signal resistor is provided by the HVAC module - DATC through circuit LH111 (BN/WH). Ground for the auxiliary controls signal resistor is provided by the HVAC module - DATC through circuit RH111 (GY/BU).
- DTC B2918 Aux Temp Blend Input Circuit Failure - The module senses an open/short in the auxiliary temperature control input to the HVAC module - DATC circuit.
- DTC B2919 Aux Blower Motor Speed Input Circuit Failure - The module senses an open/short in the auxiliary blower control input to the HVAC module - DATC circuit.
This pinpoint test is intended to diagnose the following:
- Wiring, terminals or connectors
- Rear auxiliary control
- HVAC module - DATC
PINPOINT TEST W: THE AUXILIARY TEMPERATURE, PANEL/FLOOR AND BLOWER MOTOR CONTROLS ARE INOPERATIVE/DO NOT OPERATE CORRECTLY USING THE FRONT/REAR AUXILIARY CLIMATE CONTROLS
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W1 CHECK HVAC DTCS
- Ignition ON.
- Check for HVAC DTCs.
- Is DTC B2918 or B2919 present?
Yes
One DTC present, GO to W2.
Both DTCs present, GO to W4.
No
GO to W6.
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W2 CHECK CIRCUIT VHA15 (YE/GY) OR VHA17 (VT/GN) FOR AN OPEN
- Ignition OFF.
- Disconnect: Auxiliary Controls C990.
- Disconnect: HVAC Module - DATC C228b.
DTC B2918
- NOTE: For DTC B2918 only.
- Measure the resistance between HVAC module - DATC C228b-21, circuit VHA15 (YE/GY), harness side and auxiliary controls C990-4, circuit VHA15 (YE/GY), harness side.
DTC B2919
- NOTE: For DTC B2919 only.
- Measure the resistance between HVAC module - DATC C228b-20, circuit VHA17 (VT/GN), harness side and auxiliary controls C990-2, circuit VHA17 (VT/GN), harness side.
- Are the resistances less than 5 ohms?
Yes
GO to W3.
No
REPAIR circuit VHA15 (YE/GY) or VHA17 (VT/GN) for an open. CLEAR the DTCs. REPEAT the self test. TEST the system for normal operation.
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W3 CHECK CIRCUIT VHA15 (YE/GY) OR VHA17 (VT/GN) FOR A SHORT TO GROUND
- Measure the resistance between ground and HVAC module - DATC:
- For DTC B2918 only, C228b-21, circuit VHA15 (YE/GY), harness side.
- For DTC B2919 only, C228b-20, circuit VHA17 (VT/GN), harness side.
- Are the resistances greater than 10,000 ohms?
Yes
REPAIR circuit VHA15 (YE/GY) or VHA17 (VT/GN) for a short to circuit RH111 (GY/BN). CLEAR the DTCs. REPEAT the self test. TEST the system for normal operation.
No
REPAIR circuit VHA15 (YE/GY) or VHA17 (VT/GN) for a short to ground. CLEAR the DTCs. REPEAT the self test. TEST the system for normal operation.
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W4 CHECK CIRCUITS RH111 (GY/BU) AND LH111 (BN/WH) FOR AN OPEN
- Ignition OFF.
- Disconnect: Auxiliary Controls C990.
- Disconnect: HVAC Module - DATC C228a.
- Measure the resistance between HVAC module - DATC C228a-11, circuit LH111 (BN/WH), harness side and auxiliary controls C990-3, circuit LH111 (BN/WH), harness side.
- Measure the resistance between HVAC module - DATC C228a-10, circuit RH111 (GY/BU), harness side and auxiliary controls C990-1, circuit RH111 (GY/BU), harness side.
- Is the resistance greater than 10,000 ohms?
Yes
GO to W5.
No
REPAIR circuits RH111 (GY/BU) or LH111 (BN/WH) for an open. CLEAR the DTCs. REPEAT the self test. TEST the system for normal operation.
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W5 CHECK CIRCUIT LH111 (BN/WH) FOR A SHORT TO GROUND
- Measure the resistance between ground and HVAC module - DATC C228a-11, circuit LH111 (BN/WH), harness side.
- Is the resistance greater than 10,000 ohms?
Yes
INSTALL a new auxiliary control. CLEAR the DTCs. REPEAT the self test. TEST the system for normal operation.
No
REPAIR circuit LH111 (BN/WH) for a short to ground. CLEAR the DTCs. REPEAT the self test. TEST the system for normal operation.
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W6 CHECK CIRCUITS VHA15 (YE/GY) AND VHA17 (VT/GN) FOR A SHORT TO VOLTAGE
- Ignition OFF.
- Disconnect: Auxiliary Controls C990.
- Disconnect: HVAC Module - DATC C228b.
- Ignition ON.
- Measure the voltage between HVAC module - DATC:
- C228b-20, circuit VHA17 (VT/GN), harness side.
- C228b-21, circuit VHA15 (YE/GY), harness side.
- Are any voltages present?
Yes
REPAIR circuit VHA15 (YE/GY) or VHA17 (VT/GN) for a short to voltage. TEST the system for normal operation.
No
GO to W7.
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W7 CHECK CIRCUIT RH111 (GY/BU) FOR A SHORT TO VOLTAGE
- Measure the voltage between ground and HVAC module - DATC C228a-10, circuit RH111 (GY/BU), harness side.
- Is any voltage present?
Yes
REPAIR circuit RH111 (GY/BU) for a short to voltage. TEST the system for normal operation.
No
GO to W8.
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W8 CHECK CIRCUITS RH111 (GY/BU) AND LH111 (BN/WH) FOR A SHORT TOGETHER
- Ignition OFF.
- Measure the resistance between HVAC module - DATC C228a-11, circuit LH111 (BN/WH), harness side and HVAC module - DATC C228a-10, circuit RH111 (GY/BU), harness side.
- Is the resistance greater than 500 ohms?
Yes
GO to W9.
No
REPAIR circuits RH111 (GY/BU) and LH111 (BN/WH) for a short together. TEST the system for normal operation.
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W9 CHECK CIRCUITS VHA15 (YE/GY) AND VHA17 (VT/GN) FOR A SHORT TOGETHER
- Measure the resistance between HVAC module - DATC C228b-21, circuit VHA15 (YE/GY), harness side and HVAC module - DATC C228b-20, circuit VHA17 (VT/GN), harness side.
- Is the resistance greater than 10,000 ohms?
Yes
INSTALL a new auxiliary control. TEST the system for normal operation.
No
REPAIR circuits VHA15 (YE/GY) and VHA17 (VT/GN) for a short together. TEST the system for normal operation.
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