DTC Troubleshooting: P0100 (K20C2) - Honda Civic FC/FK 2016-2021

1.

Problem verification:

Problem verification

?1.	Turn the vehicle to the ON mode.

?2.	Clear the DTC with the HDS.

?3.	Wait 2 seconds or more.

?4.

Check for Pending or Confirmed DTCs with the HDS.

DTC Description	Confirmed DTC	Pending DTC
P0100 MAF Sensor Circuit Malfunction

Is DTC P0100 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 MAF sensor/IAT sensor 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.?

2.

Determine possible failure area (VGP line, others):

Determine possible failure area (VGP line, others)

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

?2.

Disconnect the following connector.

MAF sensor/IAT sensor 4P connector

?3.	Turn the vehicle to the ON mode.

?4.

Measure the voltage between test points 1 and 2.

Test condition	Vehicle ON mode
	MAF sensor/IAT sensor 4P connector: disconnected
Test point 1	MAF sensor/IAT sensor 4P connector No. 2
Test point 2	MAF sensor/IAT sensor 4P connector No. 3

Is there about 5.0 V?


	YES

Go to step 6.


	NO

Go to step 3.

3.

Shorted wire check (VCC2 line):

Shorted wire check (VCC2 line)

?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 E (80P)

?4.

Check for continuity between test points 1 and 2.

Test condition	Vehicle OFF (LOCK) mode
	MAF sensor/IAT sensor 4P connector: disconnected
	PCM connector E (80P): disconnected
Test point 1	MAF sensor/IAT sensor 4P connector No. 3
Test point 2	Body ground

Is there continuity?


	YES

Repair a short in the VCC2 wire between the PCM (E77) and the MAF sensor/IAT sensor.?


	NO

The VCC2 wire is not shorted. Go to step 4.

4.

Open wire check (VCC2 line):

Open wire check (VCC2 line)

?1.

Check for continuity between test points 1 and 2.

Test condition	Vehicle OFF (LOCK) mode
	MAF sensor/IAT sensor 4P connector: disconnected
	PCM connector E (80P): disconnected
Test point 1	MAF sensor/IAT sensor 4P connector No. 3
Test point 2	PCM connector E (80P) No. 77

Is there continuity?


	YES

The VCC2 wire is OK. Go to step 5.


	NO

Repair an open in the VCC2 wire between the PCM (E77) and the MAF sensor/IAT sensor.?

5.

Open wire check (SG2 line):

Open wire check (SG2 line)

?1.

Check for continuity between test points 1 and 2.

Test condition	Vehicle OFF (LOCK) mode
	MAF sensor/IAT sensor 4P connector: disconnected
	PCM connector E (80P): disconnected
Test point 1	MAF sensor/IAT sensor 4P connector No. 2
Test point 2	Body ground

Is there continuity?


	YES

The SG2 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 DTC P0100 goes away and the PCM was substituted, replace the original PCM.?


	NO

Repair an open in the SG2 wire between the PCM (E78) and the MAF sensor/IAT sensor.?

6.

Shorted wire check (VGP line):

Shorted wire check (VGP line)

?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 E (80P)

?4.

Check for continuity between test points 1 and 2.

Test condition	Vehicle OFF (LOCK) mode
	MAF sensor/IAT sensor 4P connector: disconnected
	PCM connector E (80P): disconnected
Test point 1	MAF sensor/IAT sensor 4P connector No. 1
Test point 2	Body ground

Is there continuity?


	YES

Repair a short in the VGP wire between the PCM (E61) and the MAF sensor/IAT sensor.?


	NO

The VGP wire is not shorted to ground. Go to step 7.

7.

Open wire check (VGP line):

Open wire check (VGP line)

?1.

Check for continuity between test points 1 and 2.

Test condition	Vehicle OFF (LOCK) mode
	MAF sensor/IAT sensor 4P connector: disconnected
	PCM connector E (80P): disconnected
Test point 1	MAF sensor/IAT sensor 4P connector No. 1
Test point 2	PCM connector E (80P) No. 61

Is there continuity?


	YES

The VGP wire is not open. Go to step 8.


	NO

Repair an open in the VGP wire between the PCM (E61) and the MAF sensor/IAT sensor.?

8.

Shorted wire check (VGP line to power):

Shorted wire check (VGP line to power)

?1.	Turn the vehicle to the ON mode.

?2.

Measure the voltage between test points 1 and 2.

Test condition	Vehicle ON mode
	MAF sensor/IAT sensor 4P connector: disconnected
	PCM connector E (80P): disconnected
Test point 1	MAF sensor/IAT sensor 4P connector No. 1
Test point 2	Body ground

Is there any voltage?


	YES

Repair a short to power in the VGP wire between the PCM (E61) and the MAF sensor/IAT sensor.?


	NO

The VGP wire is OK. Go to step 9.

9.

MAF sensor/IAT sensor check (substitution):

MAF sensor/IAT sensor check (substitution)

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

?2.	Substitute a known-good MAF sensor/IAT sensor.

?3.	Reconnect all connectors.

?4.	Exit the SCS mode with the HDS.

?5.	Turn the vehicle to the ON mode.

?6.	Clear the DTC with the HDS.

?7.	Wait 2 seconds or more.

?8.

Check for Pending or Confirmed DTCs with the HDS.

DTC Description	Confirmed DTC	Pending DTC
P0100 MAF Sensor Circuit Malfunction

Is DTC P0100 indicated?


	YES

The MAF sensor/IAT sensor 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 DTC P0100 goes away and the PCM was substituted, replace the original PCM.?


	NO

Replace the original MAF sensor/IAT sensor.?