DTC P0A94: DC-DC Converter Performance Problem (V6, With Auto Idle Stop System)

NOTE:  Before you troubleshoot, review the general troubleshooting information - Refer to: How to Troubleshoot the Fuel and Emissions Systems (V6, With Auto Idle Stop System) .

DTC (PGM-FI)

1. DTC check

   -1. Turn the vehicle to the ON mode.

   - 2. Clear the DTC with the HDS.

   - 3. Test-drive the vehicle under the auto idle stop system operating condition, and stop the engine using auto idle stop.

   NOTE:  If the auto idle stop system indicator (amber) comes on and the engine keeps running, go to step 1-4.

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

   DTC Description	Confirmed DTC	Pending DTC	Freeze Frame
   P16E5 LIN Communication Error (PCM-DC-DC Converter)

   Is DTC P16E5 indicated?

   YES 

   Go to the troubleshooting for DTC P16E5 - Refer to: DTC Troubleshooting: P16E5 (V6, With Auto Idle Stop System) (2015-17)  or DTC Troubleshooting: P16E5 (V6) (2018-19) .

   NO 

   Go to step 2.

2. Problem verification

   -1. Check for Pending or Confirmed DTCs with the HDS.

   DTC Description	Confirmed DTC	Pending DTC	Freeze Frame
   P0A94 DC-DC Converter Performance Problem

   Is DTC P0A94 indicated?

   YES 

   The failure is duplicated. Go to step 3.

   NO 

   Check the fuses in under-dash sub fuse/relay box A and under-dash sub fuse/relay box B. If the fuse (s) is blown, repair a short in the fuse circuit. If it is OK, 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 freeze data/on-board snapshot of this DTC is recorded, try to reproduce the failure under the same conditions with the freeze data/on-board snapshot.

3. Determine possible failure area (CST line shorted, others)

   -1. Check the parameter (s) below with the HDS.

   Signal	Threshold		Current conditions
   	Values	Unit	Values	Unit
   DC-DC CONVERTER CST ERROR	Normal

   Do the current condition (s) match the threshold?

   YES 

   Go to step 5.

   NO 

   Go to step 4.

4. Shorted wire check (CST line)

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

   - 2. Jump the SCS line with the HDS.

   - 3. Disconnect the following connectors.

   DC-DC converter connector A (3P)

   PCM connector A (51P)

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

   Test condition	Vehicle OFF (LOCK) mode
   	DC-DC converter connector A (3P): disconnected
   	PCM connector A (51P): disconnected
   Test point 1	DC-DC converter connector A (3P) No. 2
   Test point 2	Body ground

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

   Is there continuity?

   YES 

   Repair a short in the CST wire between the PCM (A2) and the DC-DC converter.

   NO 

   The CST wire is OK. Replace the DC-DC converter . If DTC P0A94 was indicated after DC-DC converter replaced, update the PCM if it does not have the latest software , or substitute a known-good PCM - Refer to: PCM Removal and Installation (With SH-AWD) , then recheck. If DTC P0A94 goes away and the PCM was updated, troubleshooting is complete. If DTC P0A94 goes away and the PCM was substituted, replace the original PCM - Refer to: PCM Removal and Installation (With SH-AWD) .

5. Open wire check (DC PGND line)

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

   - 2. Disconnect the following connector.

   DC-DC converter connector B (5P)

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

   Test condition	Vehicle OFF (LOCK) mode
   	DC-DC converter connector B (5P): disconnected
   Test point 1	DC-DC converter connector B (5P) No. 4
   Test point 2	Body ground

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

   Is there continuity?

   YES 

   Go to step 6.

   NO 

   Repair an open in the DC PGND wire between the DC-DC converter and G305.

6. Determine possible failure area (DC-DC converter input/output lines)

   -1. Reconnect DC-DC converter connector B (5P).

   - 2. Turn the vehicle to the ON mode.

   - 3. Check the parameter (s) below with the HDS.

   Signal	Current conditions
   	Values	Unit
   DC-DC CONVERTER INPUT ERROR 1
   DC-DC CONVERTER INPUT ERROR 2
   DC-DC CONVERTER OUTPUT ERROR 1
   DC-DC CONVERTER OUTPUT ERROR 2

   Do these parameters indicate Malfunction?

   DC-DC converter input error 1 indicates Malfunction

   Go to step 7.

   DC-DC converter input error 2 indicates Malfunction

   Go to step 9.

   DC-DC converter output error 1 indicates Malfunction

   Check for +B DC1 OUT1 circuit shorted, or aftermarket parts connected to +B DC1 OUT1 wire. Repair a short in +B DC1 OUT1 circuit or remove the aftermarket parts if needed. If +B DC1 OUT1 wire is OK, replace the DC-DC converter .

   DC-DC converter output error 2 indicates Malfunction

   Check for +B DC1 OUT2 circuit shorted, or aftermarket parts connected to +B DC1 OUT2 wire. Repair a short in +B DC1 OUT2 circuit or remove the aftermarket parts if needed. If +B DC1 OUT2 wire is OK, replace the DC-DC converter .

   All parameters indicates Normal

   DC-DC converter input and output lines are OK. Replace the DC-DC converter .

7. Fuse check

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

   - 2. Check the following fuse.

   Fuse	No. D8 (30 A)
   Location	Auxiliary under-dash fuse box

   Is the fuse OK?

   YES 

   Go to step 8.

   NO 

   Check for a short in the +B DCDC1 IN1 wire between the DC-DC converter and the No. D8 (30 A) fuse, the +B DC1 OUT1 wire between the DC-DC converter and under-dash sub fuse/relay box A, and repair it if needed. Also replace the No. D8 (30 A) fuse.

8. Open wire check (+B DCDC1 IN1 line)

   -1. Disconnect the following connector.

   DC-DC converter connector B (5P)

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

   Test condition	Vehicle OFF (LOCK) mode
   	DC-DC converter connector B (5P): disconnected
   Test point 1	DC-DC converter connector B (5P) No. 1
   Test point 2	Body ground

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

   Is there battery voltage?

   YES 

   The +B DCDC1 IN1 wire is OK. Replace the DC-DC converter . If DTC P0A94 was indicated after DC-DC converter replaced, update the PCM if it does not have the latest software , or substitute a known-good PCM - Refer to: PCM Removal and Installation (With SH-AWD) , then recheck. If DTC P0A94 goes away and the PCM was updated, troubleshooting is complete. If DTC P0A94 goes away and the PCM was substituted, replace the original PCM - Refer to: PCM Removal and Installation (With SH-AWD) .

   NO 

   Repair an open in the +B DCDC1 IN1 wire between the DC-DC converter and the No. D8 (30 A) fuse in the auxiliary under-dash fuse box.

9. Fuse check

   -1. Check the following fuse.

   Fuse	No. D5 (30 A)
   Location	Auxiliary under-dash fuse box

   Is the fuse OK?

   YES 

   Go to step 10.

   NO 

   Check for a short in the +B DCDC1 IN2 wire between the DC-DC converter and the No. D5 (30 A) fuse, the +B DC1 OUT2 wire between the DC-DC converter and under-dash sub fuse/relay box B, and repair it if needed. If the wires are OK, replace the DC-DC converter . Also replace the No. D5 (30 A) fuse.

10. Open wire check (+B DCDC1 IN2 line)

    -1. Disconnect the following connector.

    DC-DC converter connector B (5P)

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

    Test condition	Vehicle OFF (LOCK) mode
    	DC-DC converter connector B (5P): disconnected
    Test point 1	DC-DC converter connector B (5P) No. 2
    Test point 2	Body ground

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

    Is there battery voltage?

    YES 

    The +B DCDC1 IN2 wire is OK. Replace the DC-DC converter . If DTC P0A94 was indicated after DC-DC converter replaced, update the PCM if it does not have the latest software , or substitute a known-good PCM - Refer to: PCM Removal and Installation (With SH-AWD) , then recheck. If DTC P0A94 goes away and the PCM was updated, troubleshooting is complete. If DTC P0A94 goes away and the PCM was substituted, replace the original PCM - Refer to: PCM Removal and Installation (With SH-AWD) .

    NO 

    Repair an open in the +B DCDC1 IN2 wire between the DC-DC converter and the No. D5 (30 A) fuse in the auxiliary under-dash fuse box.