Pinpoint Test D: DTC P0AFA:16 Or P0AFB:17
Climate Control System
Pinpoint Tests
Pinpoint Test D: DTC P0AFA:16 or P0AFB:17
Refer to Wiring Diagram Set 55 (Fusion/Milan/MKZ, Fusion Hybrid/Milan Hybrid), Automatic Climate Control System for schematic and connector information. Diagrams By Number
Normal Operation
Under normal operation, the Air Conditioning Compressor Module (ACCM) receives hybrid battery system voltage through circuit HYT03 (OG/WH). The ACCM is grounded through circuit HYT04 (OG/BK).
- DTC P0AFA:16 (Hybrid Battery System Voltage Low: Circuit Voltage Below Threshold) - The module senses when hybrid battery system voltage is less than 165 volts.
- DTC P0AFB:17 (Hybrid Battery System Voltage High: Circuit Voltage Above Threshold) - The module senses when hybrid battery system voltage is greater than 450 volts.
This pinpoint test is intended to diagnose the following:
- Wiring, terminals or connectors
- ACCM
PINPOINT TEST D: DTC P0AFA:16 OR P0AFB:17
WARNING: To prevent the risk of high-voltage shock, always follow precisely all warnings and service instructions, including instructions to depower the system. The high-voltage hybrid system utilizes approximately 300 volts DC, provided through high-voltage cables to its components and modules. The high-voltage cables and wiring are identified by orange harness tape or orange wire covering. All high-voltage components are marked with high-voltage warning labels with a high-voltage symbol. Failure to follow these instructions may result in serious personal injury or death.
NOTE: Before carrying out the following test, diagnose any PCM or Battery Energy Control Module (BECM) DTCs.
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D1 CHECK THE HIGH-VOLTAGE BEC HIGH-VOLTAGE LOW-CURRENT FUSE
WARNING: Never install the service disconnect plug with the high-voltage bussed electrical center (BEC) cover removed. Always install the cover prior to connecting the service disconnect plug. The high-voltage BEC cover prevents inadvertent contact with the high voltage which is present at several points under the cover. Failure to follow these instructions may result in serious personal injury or death.
- Ignition OFF.
- Depower the HVTB. Refer to Hybrid Drive Systems.
- Remove the high-voltage Bussed Electrical Center (BEC) cover. Refer to the High-Voltage Low-Current Fuse procedure in Hybrid Drive Systems.
- Inspect and measure the resistance of the high-voltage low-current fuse.
- Is the fuse undamaged and the resistance less than 5 ohms?
Yes
GO to D2.
No
INSTALL a new high-voltage, low-current fuse. INSPECT the high-voltage BEC for signs of an obvious short condition. INSTALL a new high-voltage BEC as needed. If an obvious short condition is not identified, CARRY OUT self-test of the Battery Energy Control Module (BECM). REFER to Hybrid Drive Systems to diagnose BECM DTCs.
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D2 COMPARE THE ACCM HIGH VOLTAGE PID WITH THE BECM HIGH VOLTAGE PID
- Ignition ON.
- Enter the following diagnostic mode on the scan tool: Hybrid Battery Pack Voltage (BATPACKVOLT) Battery Energy Control Module (BECM) PID.
- Enter the following diagnostic mode on the scan tool: Electric A/C Compressor High Voltage Supply (ACCM_CHVS) Air Conditioning Compressor Module (ACCM) PID.
- Compare the BATPACKVOLT BECM PID voltage with the ACCM_CHVS ACCM PID voltage.
- Are both voltages approximately the same?
Yes
CLEAR the DTCs. REPEAT the self-test. TEST the system for normal operation. If the DTCs return, INSTALL a new ACCM. TEST the system for normal operation. If the DTCs do not return, the system is operating correctly at this time. The concern may have been caused by a loose or corroded connector.
No
INSPECT the ACCM for loose or corroded connections. If OK, INSTALL a new ACCM. TEST the system for normal operation.
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