DTC P0102:00

MAF sensor circuit low input

DETECTION CONDITION

• The PCM monitors input voltage from the MAF sensor. If the input voltage at the PCM terminal 2BC is below 0.2 V for 5 s, the PCM determines that the MAF sensor circuit has a malfunction.

Diagnostic support note

• This is a continuous monitor (CCM).

• The check engine light illuminates if the PCM detects the above malfunction condition during the first drive cycle.

• FREEZE FRAME DATA/Snapshot data is available.

• DTC is stored in the PCM memory.

FAIL-SAFE FUNCTION

• Restricts the upper limit of the engine speed.

• Inhibits the evaporative purge control.

POSSIBLE CAUSE

• MAF sensor/IAT sensor No.1 connector or terminals malfunction

• Short to ground or open circuit in MAF sensor power supply circuit

• Short to ground in wiring harness between ENGINE1 10 A fuse and MAF sensor/IAT sensor No.1 terminal E

• ENGINE1 10 A fuse malfunction

• Open circuit in wiring harness between main relay terminal C and MAF sensor/IAT sensor No.1 terminal E

• Short to ground in wiring harness between the following terminals:

• MAF sensor/IAT sensor No.1 terminal D—PCM terminal 2BB

• MAF sensor/IAT sensor No.1 terminal C—PCM terminal 2BC

• PCM connector or terminals malfunction

• MAF sensor signal circuit and ground circuit are shorted to each other

• Open circuit in wiring harness between the following terminals:

• MAF sensor/IAT sensor No.1 terminal D—PCM terminal 2BB

• MAF sensor/IAT sensor No.1 terminal C—PCM terminal 2BC

• MAF sensor malfunction

• PCM malfunction

Item (definition)

Unit/Condition

Definition

Condition/Specification (Reference)

MAF

g/Sec

Mass air flow input from MAF sensor

• Displays MAF

V

MAF sensor voltage

• Ignition switched ON (engine off) (MAF: 0.39 g/s {0.052 lb/min}): Approx. 0.72 V (ECT is 89 °C {192 °F})

• Idle (after warm up) (MAF: 4.29 g/s {0.567 lb/min}): Approx. 1.15 V (ECT is 88 °C {190 °F})

• Racing (engine speed is 2,000 rpm) (MAF: 4.32 g/s {0.571 lb/min}): Approx. 1.15 V (ECT is 89 °C {192 °F})

• Racing (engine speed is 4,000 rpm) (MAF: 12.71 g/s {1.681 lb/min}): Approx. 1.66 V (ECT is 89 °C {192 °F})

STEP

INSPECTION

ACTION

1

NOTE:

• Recording can be facilitated using the screen capture function of the PC.

• Record the FREEZE FRAME DATA/snapshot data on the repair order.

—

Go to the next step.

2

• Verify related Service Bulletins and/or on-line repair information availability.

• Is any related repair information available?

Yes

Perform repair or diagnosis according to the available repair information.

• If the vehicle is not repaired, go to the next step.

No

Go to the next step.

3

• Switch the ignition off.

• Disconnect the MAF sensor/IAT sensor No.1 connector.

• Inspect for poor connection (such as damaged/pulled-out pins, corrosion).

• Is there any malfunction?

Yes

Repair or replace the connector and/or terminals, then go to Step 10.

No

Go to the next step.

4

• Verify that the MAF sensor/IAT sensor No.1 connector is disconnected.

• Switch the ignition ON (engine off).

  NOTE:

  • Another DTC may be stored by the PCM detecting an open circuit.

• Measure the voltage at the MAF sensor/IAT sensor No.1 terminal E (wiring harness-side).

• Is the voltage B+?

Yes

Go to the next step.

No

Inspect the ENGINE1 10 A fuse.

• If the fuse is blown:

• Refer to the wiring diagram and verify whether or not there is a common connector between ENGINE1 10 A fuse and MAF sensor/IAT sensor No.1 terminal E.

If there is a common connector:

• Determine the malfunctioning part by inspecting the common connector and the terminal for corrosion, damage, or pin disconnection, and the common wiring harness for a short to ground.

• Repair or replace the malfunctioning part.

If there is no common connector:

• Repair or replace the wiring harness which has a short to ground.

• Replace the fuse.

• If the fuse is damaged:

• Replace the fuse.

• If the fuse is normal:

• Refer to the wiring diagram and verify whether or not there is a common connector between main relay terminal C and MAF sensor/IAT sensor No.1 terminal E.

If there is a common connector:

• Determine the malfunctioning part by inspecting the common connector and the terminal for corrosion, damage, or pin disconnection, and the common wiring harness for an open circuit.

• Repair or replace the malfunctioning part.

If there is no common connector:

• Repair or replace the wiring harness which has an open circuit.

Go to Step 10.

5

• Verify that the MAF sensor/IAT sensor No.1 connector is disconnected.

• Switch the ignition off.

• Inspect for continuity between the following terminals (wiring harness-side) and body ground:

• MAF sensor/IAT sensor No.1 terminal D

• MAF sensor/IAT sensor No.1 terminal C

• Is there continuity?

Yes

Disconnect the PCM connector and inspect the wiring harness for short to ground.

• If the short to ground circuit could be detected in the wiring harness:

• Refer to the wiring diagram and verify whether or not there is a common connector between the following terminals:

• MAF sensor/IAT sensor No.1 terminal D—PCM terminal 2BB

• MAF sensor/IAT sensor No.1 terminal C—PCM terminal 2BC

If there is a common connector:

• Determine the malfunctioning part by inspecting the common connector and the terminal for corrosion, damage, or pin disconnection, and the common wiring harness for a short to ground.

• Repair or replace the malfunctioning part.

If there is no common connector:

• Repair or replace the wiring harness which has a short to ground.

• If the short to ground circuit could not be detected in the wiring harness:

• Replace the PCM (short to ground in the PCM internal circuit).

  (See PCM REMOVAL/INSTALLATION [SKYACTIV-G 2.0].)

Go to Step 10.

No

Go to the next step.

6

• Disconnect the PCM connector.

• Inspect for poor connection (such as damaged/pulled-out pins, corrosion).

• Is there any malfunction?

Yes

Repair or replace the connector and/or terminals, then go to Step 10.

No

Go to the next step.

7

• Verify that the MAF sensor/IAT sensor No.1 and PCM connectors are disconnected.

• Inspect for continuity between MAF sensor/IAT sensor No.1 terminals C and B (wiring harness-side).

• Is there continuity?

Yes

Refer to the wiring diagram and verify whether or not there is a common connector between the following terminals:

• MAF sensor/IAT sensor No.1 terminal C—PCM terminal 2BC

• MAF sensor/IAT sensor No.1 terminal B—PCM terminal 2AY

If there is a common connector:

• Determine the malfunctioning part by inspecting the common connector and the terminal for corrosion, damage, or pin disconnection, and the common wiring harness for a short to each other.

• Repair or replace the malfunctioning part.

If there is no common connector:

• Repair or replace the wiring harness which has a short to each other.

Go to Step 10.

No

Go to the next step.

8

• Verify that the MAF sensor/IAT sensor No.1 and PCM connectors are disconnected.

• Inspect for continuity between the following terminals (wiring harness-side):

• MAF sensor/IAT sensor No.1 terminal D—PCM terminal 2BB

• MAF sensor/IAT sensor No.1 terminal C—PCM terminal 2BC

• Is there continuity?

Yes

Go to the next step.

No

Refer to the wiring diagram and verify whether or not there is a common connector between the following terminals:

• MAF sensor/IAT sensor No.1 terminal D—PCM terminal 2BB

• MAF sensor/IAT sensor No.1 terminal C—PCM terminal 2BC

If there is a common connector:

• Determine the malfunctioning part by inspecting the common connector and the terminal for corrosion, damage, or pin disconnection, and the common wiring harness for an open circuit.

• Repair or replace the malfunctioning part.

If there is no common connector:

• Repair or replace the wiring harness which has an open circuit.

Go to Step 10.

9

• Inspect the MAF sensor.

  (See MASS AIR FLOW (MAF) SENSOR INSPECTION [SKYACTIV-G 2.0].)

• Is there any malfunction?

Yes

Replace the MAF sensor/IAT sensor No.1, then go to the next step.

(See MASS AIR FLOW (MAF) SENSOR/INTAKE AIR TEMPERATURE (IAT) SENSOR NO.1 REMOVAL/INSTALLATION [SKYACTIV-G 2.0].)

No

Go to the next step.

10

• Always reconnect all disconnected connectors.

• Clear the DTC from the PCM memory using the M-MDS.

  (See AFTER REPAIR PROCEDURE [PCM (SKYACTIV-G 2.0)].)

• Perform the KOEO or KOER self test.

  (See KOEO/KOER SELF TEST [PCM (SKYACTIV-G 2.0)].)

• Is the same DTC present?

Yes

Repeat the inspection from Step 1.

• If the malfunction recurs, replace the PCM.

  (See PCM REMOVAL/INSTALLATION [SKYACTIV-G 2.0].)

Go to the next step.

No

Go to the next step.

11

• Perform the “AFTER REPAIR PROCEDURE”.

  (See AFTER REPAIR PROCEDURE [PCM (SKYACTIV-G 2.0)].)

• Are any DTCs present?

Yes

Go to the applicable DTC inspection.

(See DTC TABLE [PCM (SKYACTIV-G 2.0)].)

No

DTC troubleshooting completed.