DTC P0657
DTC P0657 : PCM Power Supply Circuit Malfunction
| DTC Description | Confirmed DTC | Pending DTC |
|---|---|---|
| P0657 PCM Power Supply Circuit Malfunction |
DTC (PGM-FI)
- 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. Enter the maintenance mode, then start the engine .
-5. Check for Pending or Confirmed DTCs with the HDS.
DTC Description Confirmed DTC Pending DTC P0657 PCM Power Supply Circuit Malfunction DTC (PGM-FI)
Is DTC P0657 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 relay circuit board 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 .
- Relay circuit board check
-1. Turn the vehicle to the OFF (LOCK) mode.
-2. Remove and test the relay circuit board .
Is the relay circuit board OK?
YES
Go to step 3.
NO
- Fuse check
-1. Check the No. B9 fuse .
Is the fuse OK?
YES
Go to step 7.
NO
Go to step 4.
- Determine possible failure area (+B IGP line, others)
-1. Remove the blown No. B9 fuse.
-2. Check for continuity between test points 1 and 2
Test condition Vehicle OFF (LOCK) mode Relay circuit board: removed No. B9 fuse: removed Test point 1 Relay circuit board connector C (18P) (female terminals) No. 18: Test point 2 Body ground Is there continuity?
YES
Repair a short in the +B IGP wire between the No. B9 fuse and the relay circuit board. Also replace the No. B9 fuse.
NO
Go to step 5.
- Parts internal circuit check
-1. Jump the SCS line with the HDS, and wait more than 1 minute.
Check for continuity between test points 1 and 2 while disconnecting these parts or connectors, one at a time:
- PGM-FI main relay 2
- PCM connector A (50P)
- Each injector 2P connector
Test condition Vehicle OFF (LOCK) mode Relay circuit board: removed No. B9 fuse: removed Test point 1 Relay circuit board connector C (18P) (female terminals) No. 17: Test point 2 Body ground Does continuity go away with the part(s) removed?
YES
Replace the part that continuity goes away when it was disconnected. If the part is PCM, check for any authorized service information related to the DTCs or symptoms you are troubleshooting, or substitute a known-good PCM , then recheck. If DTC P0657 goes away and the PCM was substituted, replace the original PCM . Also replace the No. B9 fuse .
NO
Go to step 6.
- Shorted wire check (FI MAIN RLY OUT line)
-1. Disconnect the following connectors.
PGM-FI main relay 2 PCM connector A (50P) Each injector 2P connector -2. Check for continuity between test points 1 and 2.
Test condition Vehicle OFF (LOCK) mode Relay circuit board: removed No. B9 fuse: removed PGM-FI main relay 2: removed PCM connector A (50P): disconnected Each injector 2P connector: disconnected Test point 1 Relay circuit board connector C (18P) (female terminals) No. 17: Test point 2 Body ground Is there continuity?
YES
Repair a short in the FI MAIN RLY OUT wire between relay circuit board, PGM-FI main relay 2, the relay circuit board, the injectors, and the PCM (A8). Also replace the No. B9 fuse .
NO
Replace the relay circuit board . Also replace the No. B9 fuse.
- Open wire check (+B IGP line)
-1. Measure the voltage between test points 1 and 2.
Test condition Vehicle OFF (LOCK) mode Relay circuit board: removed Test point 1 Relay circuit board connector C (18P) (female terminals) No. 18: Test point 2 Body ground Is there battery voltage?
YES
Go to step 8.
NO
Repair an open in the +B IGP wire between the No. B9 fuse and relay circuit board.
- Open wire check (FI MAIN RLY CL- line)
-1. Jump the SCS line with the HDS, and wait more than 1 minute.
-2. Disconnect the following connector.
PCM connector A (50P) -3. Check for continuity between test points 1 and 2.
Test condition Vehicle OFF (LOCK) mode PCM connector A (50P): disconnected Relay circuit board: removed Test point 1 Relay circuit board connector C (18P) (female terminals) No. 5: Test point 2 PCM connector A (50P) No. 5 Is there continuity?
YES
The FI MAIN RLY CL- wire is OK. Go to step 9.
NO
Repair an open in the FI MAIN RLY CL- wire between the PCM (A5) and relay circuit board.
- Open wire check (FI MAIN RLY OUT line)
-1. Check for continuity between test points 1 and 2.
Test condition Vehicle OFF (LOCK) mode Relay circuit board: removed PCM connector A (50P): disconnected Test point 1 Relay circuit board connector C (18P) (female terminals) No. 17: Test point 2 PCM connector A (50P) No. 8 Is there continuity?
YES
Check for any authorized service information related to the DTCs or symptoms you are troubleshooting, or substitute a known-good PCM , then recheck. If DTC P0657 goes away and the PCM was substituted, replace the original PCM .
NO
Repair an open in the FI MAIN RLY OUT wire between the PCM (A8) and relay circuit board.