P0103

DTC P0103






GENERAL DESCRIPTION
The Delphi MAF Sensor is an air mass flowmeter, which operates on the principle of hot filmanemometry. A heated element is placed within the air stream, and maintained at a constant temperature above the air temperature. The amount of electrical power required to maintain the heated element at the proper temperature is a direct function of the flow rate of the air mass past the element. PCM uses this information to determine the injection duration and ignition timing for the desired air/fuel ratio.

DTC DESCRIPTION
The PCM compares the airmeter input frequency to low and high limits. When the frequency is outside the allowable limits, the circuit is determined to be failed.If PCM detects that frequency signal of MAFS is higher than 11900 Hz for more than 75 seconds failure during 125 seconds diagnostic test while enable condition is met PCM determines that a fault exists and a DTC is stored.MIL(Malfunction Indication Lamp) turns on when the malfunction lasts till consecutive 2 driving cycle.

DTC Detecting Condition:

DTC DETECTING CONDITION

Specification:

SPECIFICATION

Schematic Diagram:

SCHEMATIC DIAGRAM

MONITOR SCANTOOL DATA
1. IG "OFF"& connect Scantool.
2. ENG "ON" and warm -up the engine to normal operating temperature.

Specification:

3. Monitor "Air Flow" status on the service data.
4. Are the "Air Flow" data displayed correctly?

YES - Fault is intermittent caused by poor contact in the sensor`s and/or PCM`s connector or was repaired and PCM memory was not cleared. Thoroughly check connectors for looseness, poor connection, ending, corrosion, contamination, deterioration, or damage. Repair or replace as necessary and go to "Verification of Vehicle Repair" procedure

NO - Go to "Terminal and Connector Inspection" procedure

TERMINAL AND CONNECTOR INSPECTION
1. Many malfunctions in the electrical system are caused by poor harness and terminals. Faults can also be caused by interference from other electrical systems, and mechanical or chemical damage.
2. Thoroughly check connectors for looseness, poor connection, bending, corrosion, contamination,deterioration, or damage.
3. Has a problem been found?

YES - Repair or replace if necessary and go to "Verification of Vehicle Repair" procedure

NO - Go to "Ground Circuit Inspection" procedure.

GROUND CIRCUIT INSPECTION
1. IG "OFF"
2. Disconnector MAFS connector.
3. Measure the voltage between terminal 1 of MAFS harness connector.




4. Measure the voltage between terminal 1 and 3 of MAFS harness connector.

Specification : Voltage difference and "A" and B" is below 200 mV

5. Is the measured voltage within the specification?

YES - Go to "Component Inspection".

NO - After repairing or replacing contact resistance in ground circuit and open in the MAFS circuit, go to "Verification and Vehicle Repair".

COMPONENT INSPECTION
1. Visual Inspection
a. Check that MAFS is damaged, contaminated or deformed.
b. Has a problem been found?

YES - Repair or replace as necessary and then go to "Verification of Vehicle Repair" procedure.

NO - Go to "Check MAFS" as follows

2. Check MAFS
a. IG "OFF" and install a Scantool
b. ENG "ON" and monitor "MAFS" data on the service data.




c. Monitor signal waveform at terminal 1 of MAFS with Scantool.

Specification :Signal waveform will be displayed as follows. (Be aware that the signal of MAFS is not voltage display but frequency display.)

d. Are both service data and signal wave form dispayed correctly?

YES - Substitute with a known - good PCM and check for proper operation. If the problem is corrected, replace PCM and go to "Verification of Vehicle Repair" procedure.

NOTE: There is a memory reset function on Scantool that can erase optional parts automatically detected and memorized by PCM.Before or after testing PCM on the vehicle, use this function to reuse the PCM on the others

NO - Substitute with a known - good MAFS and check for proper operation. If the problem is corrected, replace MAFS and go to "Verification of Vehicle Repair" procedure.

VERIFICATION OF VEHICLE REPAIR
After a repair, it is essential to verify that the fault has been corrected.
1. Monitor and record the Freeze Frame Data for the Diagnostic Trouble Code(DTC) which has been diagnosed.
2. Using a Scantool, Clear the DTCs
3. Operate the vehicle within conditions noted in the freeze frame data or enable conditions
4. Monitor that all readiness test have been verified as "Complete".
5. Are any DTCs present?

YES - Go to the applicable troubleshooting procedure.

NO - System is performing to specification at this time.