DTC P0102-00: Maf Sensor Circuit Low Input: Notes

DTC DETECTION DESCRIPTION

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 15 A fuse and MAF sensor/IAT sensor No. 1 terminal E ENGINE1 15 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

Fig 1: MAF Sensor Circuit Diagram

Courtesy of MAZDA MOTORS CORP.

CAUTION:

• Verify the malfunction symptom according to not only the PID value but also the symptom troubleshooting.

PARTS DESCRIPTION

Item	Definition	Unit	Condition/Specification
MAF	Mass air flow input from MAF sensor	g/Sec	Displays MAF
	MAF sensor voltage	V	Ignition switched ON (engine off) (MAF: 0.59 g/s {0.078 lb/min}): Approx. 0.72 V Idle (after warm up) (MAF: 3.79 g/s {0.501 lb/min}): Approx. 0.93 V Racing (engine speed is 2, 000 rpm) (MAF: 6.96 g/s {0.921 lb/min}): Approx. 1.11 V