DTC Troubleshooting: P0A11

ElectronicCircuitSchematics-buttonADInfo-button DTC Advanced Diagnostics: P0A11DTC P0A11  : DC-DC Converter Activation Circuit Malfunction

DTC (PGM-FI)

1. Problem verification

   -1. Turn the vehicle to the ON mode.

   -2. Clear the DTC with the HDS.

   -3. Turn the vehicle to the OFF (LOCK) mode.

   -4. Test-drive the vehicle under the auto idle stop system operating condition, and stop the engine using auto idle stop - Refer to: Auto Idle Stop System Description - Operation Conditions (2019 2020) or Auto Idle Stop System Description or Auto Idle Stop System Description - Operation Conditions (2021) .

   -5. Check for Pending or Confirmed DTCs with the HDS.

   DTC Description	Confirmed DTC	Pending DTC
   P0A11 DC-DC Converter Activation Circuit Malfunction

   Is DTC P0A11 indicated?

   YES 

   The failure is duplicated. Go to step 2.

   NO 

   Intermittent failure, the system is OK at this time. Check for poor connections or loose terminals at the DC-DC converter and the PCM. If the on-board snapshot of this DTC is recorded, try to reproduce the failure under the same conditions with the on-board snapshot - Refer to: How to Troubleshoot the Fuel and Emissions Systems or How to Troubleshoot the Brake Booster Pressure Monitoring System .

2. Determine possible failure area (CST line open, others)

   -1. Turn the vehicle to the OFF (LOCK) mode.

   -2. Jump the SCS line with the HDS, and wait more than 1 minute.

   -3. Disconnect the following connector.

   PCM connector A (50P)

   -4. Turn the vehicle to the ON mode.

   -5. Measure the voltage between test points 1 and 2.

   Test condition	Vehicle ON mode
   	PCM connector A (50P): disconnected
   Test point 1	PCM connector A (50P) No. 9 - Refer to: PCM Connector for Inputs and Outputs or PCM Connector for Inputs and Outputs (2022 2023)
   Test point 2	Body ground

   Is there battery voltage?

   YES 

   Go to step 4.

   NO 

   Go to step 3.

3. Open wire check (CST line)

   -1. Turn the vehicle to the OFF (LOCK) mode.

   -2. Disconnect the following connector.

   DC-DC converter connector A (3P)

   -3. Check for continuity between test points 1 and 2.

   Test condition	Vehicle OFF (LOCK) mode
   	PCM connector A (50P): disconnected
   	DC-DC converter connector A (3P): disconnected
   Test point 1	DC-DC converter connector A (3P) (female terminals) No. 2:
   Test point 2	PCM connector A (50P) No. 9 - Refer to: PCM Connector for Inputs and Outputs or PCM Connector for Inputs and Outputs (2022 2023)

   Courtesy of HONDA, U.S.A., INC.

   Is there continuity?

   YES 

   Replace the DC-DC converter .

   NO 

   Repair an open in the CST wire between the PCM (A9) and the DC-DC converter.

4. Shorted wire check (CST line to power)

   -1. Turn the vehicle to the OFF (LOCK) mode.

   -2. Disconnect the following connector.

   DC-DC converter connector A (3P)

   -3. Turn the vehicle to the ON mode.

   -4. Measure the voltage between test points 1 and 2.

   Test condition	Vehicle ON mode
   	PCM connector A (50P): disconnected
   	DC-DC converter connector A (3P): disconnected
   Test point 1	DC-DC converter connector A (3P) (female terminals) No. 2:
   Test point 2	Body ground

   Courtesy of HONDA, U.S.A., INC.

   Is there any voltage?

   YES 

   Repair a short to power in the CST wire between the PCM (A9) and the DC-DC converter.

   NO 

   The CST wire is OK. Substitute a known-good PCM , then recheck.

   • If DTC P0A11 is not indicated, replace the original PCM .
   • If DTC P0A11 is indicated again, replace the DC-DC converter .