PCM Power and Ground Circuit Troubleshooting

NOTE: Information marked with an asterisk (*) applies to the AC power outlet equipped model.

Engine starting check
-1. Start the engine.

Does the engine start and idle smoothly?

YES (without multipurpose camera unit)

Go to the F-CAN circuit troubleshooting .

YES (with multipurpose camera unit)

Go to the troubleshooting for CAN gateway system DTC(s) .

NO

Go to step 2.

Body electrical system DTC check

-1. Check for body electrical system DTCs with the HDS.

DTC Description	Confirmed DTC

Are any DTCs indicated?

YES

Go to the troubleshooting for the body electrical system DTC(s) .

Go to step 3.

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

-2. Check the following fuse.

Fuse No. D23 (10 A)

Location Fuse holder

Is the fuse OK?

YES

Go to step 4.

NO

Go to step 5.

Open wire check (+B VBUM(10A) 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. 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. 5
Test point 2	Body ground

Is there battery voltage?

YES

The +B VBUM(10A) wire is OK. Go to step 6.

Repair an open in the +B VBUM(10A) wire between the PCM (A5) and the No. D23 (10 A) fuse in the fuse holder.

Shorted wire check (+B VBUM(10A) line)

-1. Remove the blown No. D23 (10 A) fuse from the fuse holder.

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

-3. Disconnect the following connector.

PCM connector A (50P)

-4. Check for continuity 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. 5
Test point 2	Body ground

Is there continuity?

YES

Repair a short in the +B VBUM(10A) wire between the PCM (A5) and the No. D23 (10 A) fuse in the fuse holder. Also replace the No. D23 (10 A) fuse.

Go to step 6.

Fuse check 2

-1. Check the following fuse.

Fuse	No. B9 (15 A)
Location	Under-hood fuse/relay box

Is the fuse OK?

YES

Go to step 10.

Go to step 7.

Shorted wire check (+B MAIN RLY line)

-1. Remove the blown No. B9 (15 A) fuse from the under-hood fuse/relay box.

-2. Remove PGM-FI main relay 1 .

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

Test condition	Vehicle OFF (LOCK) mode
	PCM connector A (50P): disconnected
	PGM-FI main relay 1: disconnected
Test point 1	PGM-FI main relay 1 4P socket (female terminals) No. 1 and No. 3:
Test point 2	Body ground

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

Is there continuity?

YES

Repair a short in the +B MAIN RLY wire between the No. B9 (15 A) fuse and PGM-FI main relay 1. If the wire is OK, replace the under-hood fuse/relay box . Also replace the No. B9 (15 A) fuse.

Go to step 8.

Part(s) internal circuit check (short in IGP1 circuit):

Disconnect each of the parts or connectors below, one at a time, then check for continuity between test points 1 and 2.

ETCS control relay
PCM connector A (50P)
CMP sensor 3P connector
CKP sensor 3P connector
No. B27 (5 A) fuse in the under-hood fuse/relay box
Power distribution module connector A (18P)

Test condition	Vehicle OFF (LOCK) mode
	PGM-FI main relay 1: disconnected
Test point 1	PGM-FI main relay 1 4P socket (female terminals) No. 2:
Test point 2	Body ground

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

Does continuity go away when one of the above components is disconnected?

YES

Replace the part that made the short to body ground go away when it was disconnected. If the part is the 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 the symptom/indication goes away and the PCM was substituted, replace the original PCM . Also replace the No. B9 (15 A) fuse in the under-hood fuse/relay box.

Parts are OK. Go to step 9.

Shorted wire check (IGP1 line):

Disconnect the following parts or connectors:

ETCS control relay
PCM connector A (50P)
CMP sensor 3P connector
CKP sensor 3P connector
No. B27 (5 A) fuse in the under-hood fuse/relay box
Power distribution module connector A (18P)

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

Test condition	Vehicle OFF (LOCK) mode
	PGM-FI main relay 1: disconnected
	ETCS control relay: disconnected
	PCM connector A (50P): disconnected
	CMP sensor 3P connector: disconnected
	CKP sensor 3P connector: disconnected
	No. B27 (5 A) fuse: disconnected
	Power distribution module connector A (18P): disconnected
Test point 1	PGM-FI main relay 1 4P socket (female terminals) No. 2:
Test point 2	Body ground

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

Is there continuity?

YES

Repair a short in the IGP1 wire between PGM-FI main relay 1 and each part. Also replace the No. B9 (15 A) fuse in the under-hood fuse/relay box.

The IGP1 wire is OK. Replace PGM-FI main relay 1. Also replace the No. B9 (15 A) fuse in the under-hood fuse/relay box.

Fuse check 3

-1. Check the following fuse.

Fuse	No. C21 (20 A)
Location	Under-dash fuse/relay box

Is the fuse OK?

YES

Go to step 14.

Go to step 11.

Determine possible failure area (IG1 FUEL PUMP line, others)

-1. Check for continuity 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. 6
Test point 2	Body ground

Is there continuity?

YES

Go to step 12.

Go to step 13.

Shorted wire check (IG1 FUEL PUMP line)

-1. Disconnect the following connectors.

Power distribution module connector D (8P)

Under-dash fuse/relay box connector E (18P)

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

Test condition	Vehicle OFF (LOCK) mode
	PCM connector A (50P): disconnected
	Power distribution module connector D (8P): disconnected
	Under-dash fuse/relay box connector E (18P): disconnected
Test point 1	PCM connector A (50P) No. 6
Test point 2	Body ground

Is there continuity?

YES

Repair a short in the IG1 FUEL PUMP wire between the PCM (A6) and the No. C21 (20 A) fuse in the under-dash fuse/relay box.

The IG1 FUEL PUMP wire is OK. Check for any authorized service information related to the DTCs or symptoms you are troubleshooting, or substitute a known-good PCM , then recheck. If the symptom/indication goes away and the PCM was substituted, replace the original PCM . Also replace the No. C21 (20 A) fuse in the under-dash fuse/relay box.

Shorted wire check (+B FUEL PUMP line)

-1. Disconnect the following connectors.

Power distribution module connector D (8P)

Fuel tank unit 4P connector

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

Test condition	Vehicle OFF (LOCK) mode
	PCM connector A (50P): disconnected
	Power distribution module connector D (8P): disconnected
	Fuel tank unit 4P connector: disconnected
Test point 1	Power distribution module connector D (8P) No. 6
Test point 2	Body ground

Is there continuity?

YES

Repair a short in the +B FUEL PUMP wire between the power distribution module and the fuel tank unit. Also replace the No. C21 (20 A) fuse in the under-dash fuse/relay box.

The +B FUEL PUMP wire is OK. Check the fuel pump, and replace it if needed. Also replace the No. C21 (20 A) fuse in the under-dash fuse/relay box.

Open wire check (IG1 FUEL PUMP line)

-1. Turn the vehicle to the ON mode.

-2. 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. 6
Test point 2	Body ground

Is there battery voltage?

YES

The IG1 FUEL PUMP wire is OK. Go to step 15.

Repair an open in the IG1 FUEL PUMP wire between the PCM (A6) and the No. C21 (20 A) fuse in the under-dash fuse/relay box.

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
Test point 1	PCM connector A (50P) No. 22
Test point 2	Body ground

Is there battery voltage?

YES

Go to step 18.

Go to step 16.

Open wire check (+B MAIN RLY 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
	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

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

Is there battery voltage?

YES

Go to step 17.

Repair an open in the +B MAIN RLY wire between the No. B9 (15 A) fuse in the under-hood fuse/relay box and PGM-FI main relay 1. If the wire is OK, replace the under-hood fuse/relay box .

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
	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. 22

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

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 , then recheck. If the symptom/indication goes away and the PCM was substituted, replace the original PCM .

Repair an open in the FI MAIN RLY CL- wire between the PCM (A22) and PGM-FI main relay 1.

Open wire check (+B MAIN RLY line)

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

-2. Remove PGM-FI main relay 1 .

-3. Measure the voltage between test points 1 and 2.

Test condition	Vehicle OFF (LOCK) mode
	PCM connector A (50P): 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

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

Is there battery voltage?

YES

Go to step 19.

Repair an open in the +B MAIN RLY wire between PGM-FI main relay 1 and the No. B9 (15 A) fuse in the under-hood fuse/relay box. If the wire is OK, replace the under-hood fuse/relay box .

Open wire check (IGP1 line)

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

Test condition	Vehicle OFF (LOCK) mode
	PCM connector A (50P): 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. 4

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

Is there continuity?

YES

The IGP1 wire is OK. Go to step 20.

Repair an open in the IGP1 wire between the PCM (A4) and PGM-FI main relay 1.

Relay check
-1. Test PGM-FI main relay 1 .

Is the relay OK?

YES

Go to step 21.

NO

Replace PGM-FI main relay 1.

Open wire check (GND1 line, GND2 LG line, GND3 line, PGM line, INJGND1 line, INJGND2 line)

-1. Disconnect the following connector.

PCM connector E (80P)

-2. Check for continuity between the following test points and body ground individually.

Test condition	Vehicle OFF (LOCK) mode
	PCM connector A (50P): disconnected
	PGM-FI main relay 1: disconnected
	PCM connector E (80P): disconnected

Connector	Terminal
PCM connector E (80P)	No. 8, 15, 22, 25, 26, 27

Is there continuity?

YES

The GND1 wire, the GND2 LG wire, the GND3 wire, the PGM wire, the INJGND1 wire, and the INJGND2 wire are OK. Check for any authorized service information related to the DTCs or symptoms you are troubleshooting, or substitute a known-good PCM , then recheck. If the symptom/indication goes away and the PCM was substituted, replace the original PCM .

Repair an open in the GND1 wire, the GND2 LG wire, the GND3 wire, the PGM wire, the INJGND1 wire, and/or the INJGND2 wire between the PCM (E8, E15, E22, E25, E26, E27) and G101.