PCM Power and Ground Circuit Troubleshooting
PCM Power and Ground Circuit Troubleshooting
- Engine starting check
-1. Enter the maintenance mode, then try to start the engine .
Does the engine start and idle smoothly?
YES
Go to the troubleshooting for CAN gateway system DTC(s) .
NO
Go to step 2.
- Fuse check 1
-1. Turn the vehicle to the OFF (LOCK) mode.
-2. Check the No. B9 fuse .
Is the fuse OK?
YES
Go to step 3.
NO
Replace the No. B9 fuse. Also check for a short to ground on the No. B9 fuse circuit if needed.
- Determine possible failure area (+B VBU line, others)
-1. Jump the SCS line with the HDS, and wait more than 1 minute.
-2. Disconnect the following connector.
PCM connector A (50P) -3. Measure the voltage between test points 1 and 2.
Test condition Vehicle OFF (LOCK) mode PCM connector A (50P): disconnected Test point 1 PCM connector A (50P) No. 7 Test point 2 Body ground Is there battery voltage?
YES
Go to step 4.
NO
Repair an open in the +B VBU wire between PCM (A7) and the No. B9 fuse.
- Fuse check 2
-1. Check the No. B11 fuse .
Is the fuse OK?
YES
Go to step 5.
NO
Replace the No. B11 fuse. Also check for a short to ground on the No. B11 fuse circuit if needed.
- Fuse check 3
-1. Check the No. C8 fuse .
Is the fuse OK?
YES
Go to step 6.
NO
Replace the No. C8 fuse. Also check for a short to ground on the No. C8 fuse circuit if needed.
- Open wire check (IG1 FUEL PUMP line)
-1. Remove PGM-FI main relay 2 .
-2. Turn the vehicle to the ON mode.
-3. Measure the voltage between test points 1 and 2.
Test condition Vehicle ON mode PCM connector A (50P): disconnected PGM-FI main relay 2: disconnected Test point 1 PGM-FI main relay 2 4P socket (female terminals) No. 1: Test point 2 Body ground Is there battery voltage?
YES
The IG1 FUEL PUMP wire is OK. Go to step 7.
NO
Repair an open in the IG1 FUEL PUMP wire between the No. C8 fuse and PGM-FI main relay 2.
- Open wire check (IG1(IG1MONI)/IG1 FUEL PUMP line)
-1. Turn the vehicle to the OFF (LOCK) mode.
-2. Disconnect the following connector.
PCM connector E (80P) -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 PCM connector E (80P): disconnected PGM-FI main relay 2: disconnected Test point 1 PCM connector E (80P) No. 36 Test point 2 Body ground Is there battery voltage?
YES
The IG1(IG1MONI)/IG1 FUEL PUMP wire is OK. Go to step 8.
NO
Repair an open in the IG1(IG1MONI)/IG1 FUEL PUMP wire between the PCM (E36) and the No. C8 fuse.
- Determine possible failure area (PGM-FI main relay 1 control circuit, others)
-1. Turn the vehicle to the OFF (LOCK) mode.
-2. Measure the voltage between test points 1 and 2.
Test condition Vehicle OFF (LOCK) mode PCM connector A (50P): disconnected PCM connector E (80P): disconnected Test point 1 PCM connector A (50P) No. 5 Test point 2 Body ground Is there battery voltage?
YES
Go to step 11.
NO
Go to step 9.
- Open wire check (+B IGP line)
-1. Remove PGM-FI main relay 1.
-2. Measure the voltage between test points 1 and 2.
Test condition Vehicle OFF (LOCK) mode PCM connector A (50P): disconnected PCM connector E (80P): disconnected PGM-FI main relay 1: disconnected Test point 1 PGM-FI main relay 1 4P socket (female terminals) No. 3: Test point 2 Body ground Is there battery voltage?
YES
Go to step 10.
NO
Repair an open in the +B IGP wire between PGM-FI main relay 1 and the No. B11 fuse.
- Open wire check (FI MAIN RLY CL- line)
-1. Check for continuity between test points 1 and 2.
Test condition Vehicle OFF (LOCK) mode PCM connector A (50P): disconnected PCM connector E (80P): disconnected PGM-FI main relay 1: disconnected Test point 1 PGM-FI main relay 1 4P socket (female terminals) No. 4: Test point 2 PCM connector A (50P) No. 5 Is there continuity?
YES
The FI MAIN RLY CL- wire is OK. Test PGM-FI main relay 1 . If the relay is OK, check for any authorized service information related to the DTCs or symptoms you are troubleshooting, or substitute a known-good PCM .
NO
Repair an open in the FI MAIN RLY CL- wire between the PCM (A5) and PGM-FI main relay 1.
- Open wire check (FI MAIN RLY OUT line)
-1. Check for continuity between test points 1 and 2.
Test condition Vehicle OFF (LOCK) mode PCM connector A (50P): disconnected PCM connector E (80P): disconnected PGM-FI main relay 1: disconnected Test point 1 PGM-FI main relay 1 4P socket (female terminals) No. 2: Test point 2 PCM connector A (50P) No. 8 Is there continuity?
YES
The FI MAIN RLY OUT wire is OK. Go to step 12.
NO
Repair an open in the FI MAIN RLY OUT wire between the PCM (A8) and PGM-FI main relay 1.
- Open wire check (+B IGP line)
-1. Measure the voltage between test points 1 and 2.
Test condition Vehicle OFF (LOCK) mode PCM connector A (50P): disconnected PCM connector E (80P): disconnected PGM-FI main relay 1: disconnected Test point 1 PGM-FI main relay 1 4P socket (female terminals) No. 1: Test point 2 Body ground Is there battery voltage?
YES
Go to step 13.
NO
Repair an open in the +B IGP wire between PGM-FI main relay 1 and the No. B11 fuse.
- Relay check
-1. Test PGM-FI main relay 1 .
Is the relay OK?
YES
The PGM-FI main relay 1 is OK. Go to step 14.
NO
- Open wire check (GND lines)
-1. Check for continuity between the following test points and body ground individually.
Test condition Vehicle OFF (LOCK) mode PCM connector A (50P): disconnected PCM connector E (80P): disconnected PGM-FI main relay 1: removed Connector Terminal PCM connector A (50P) No. 13 PCM connector E (80P) No. 22 No. 23 No. 24 Is there continuity?
YES
The GND, GND2, GND3, and GND4 wires are OK. Check for any authorized service information related to the DTCs or symptoms you are troubleshooting, or substitute a known-good PCM .
NO
Repair an open in the GND, or GND2 wire between the PCM (A13, E24) and G101, or an open in the GND3, or GND4 wire between the PCM (E22, E23) and G102.