Pinpoint Test D: DTC P0AFA:16 Or P0AFB:17: Overview

WARNING: This page is about a different car, the 2011 Mercury Milan, 2011 Lincoln MKZ, and 2011 Ford Fusion. However, it is still accessible from the selected car via links, so may be relevant.

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.

D1 CHECK THE DTCs FROM THE SELF-TEST
- Review the DTCs retrieved and recorded during Inspection and Verification.
- Are there any other Battery Energy Control Module (BECM), PCM or Transmission Control Module (TCM) DTCs present along with BECM DTCs P0AFA:16 and P0AFB:17?
1. Yes : DIAGNOSE all other BECM, PCM or TCM DTCs before diagnosing BECM DTCs P0AFA:16 and P0AFB: 17.
  For BECM DTCs, REFER to HIGH VOLTAGE TRACTION BATTERY -- FUSION HYBRID, MILAN HYBRID & MKZ HYBRID article.
  
  For PCM DTCs, REFER to the INTRODUCTION - GASOLINE MODELS article.
  
  For TCM DTCs, REFER to AUTOMATIC TRANSAXLE/TRANSMISSION - AISIN AW21 -- FUSION & MKZ article or AUTOMATIC TRANSAXLE/TRANSMISSION - 6F35 -- FUSION & MILAN article.
2. No : GO to D2.
D2 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 HIGH VOLTAGE TRACTION BATTERY -- FUSION HYBRID, MILAN HYBRID & MKZ HYBRID article.
- Remove the high-voltage Bussed Electrical Center (BEC) cover. Refer to the High-Voltage Low-Current Fuse procedure in HIGH VOLTAGE TRACTION BATTERY -- FUSION HYBRID, MILAN HYBRID & MKZ HYBRID . article
- Inspect and measure the resistance of the high-voltage low-current fuse.
  
  Fig 1: Checking High-Voltage BEC High-Voltage Low-Current Fuse
  Courtesy of FORD MOTOR CO.
- Is the fuse undamaged and the resistance less than 5 ohms?
1. Yes : GO to D3.
2. 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 HIGH VOLTAGE TRACTION BATTERY -- FUSION HYBRID, MILAN HYBRID & MKZ HYBRID article to diagnose BECM DTCs. CLEAR the DTCs from all modules. REPEAT self-test.
D3 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?
1. Yes : CLEAR the DTCs from all modules. REPEAT the self-test. TEST the system for normal operation. If the DTCs return , INSTALL a new ACCM. REFER to CLIMATE CONTROL -- FUSION, MILAN & MKZ article. 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.
2. No : INSPECT the ACCM for loose or corroded connections. If OK, INSTALL a new ACCM. REFER to CLIMATE CONTROL -- FUSION, MILAN & MKZ article. TEST the system for normal operation.