Check Maf Kia Carnival Diesel

7/24/2019 Check Maf Kia Carnival Diesel

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2009 >D 2.9 WGT >Mass Air Flow Sensor (MAFS) >P0103

COMPONENT LOCATION

GENERAL DESCRIPTION

Intake Air Temperature Sensor(IATS) is hot film sensor and senses mass air flow. ECM performs EGR

system feed back control with the information of measured mass air flow. (The role of MAFS in diesel

engine is different from gasoline engine. Fuel injection quantity is decided by MAFS signal in gasoline

engine.)When EGR gas(contains no oxygen) flowing into combustion chamber increases, the air

passing through MAFS(contains oxygen) decreases. Thus, with the output signal change of MAFS

accompanied by EGR actuator actuation, ECM determines the amount of recirculated EGR gas

quantity.

NOx is produced from the reaction of nitrogen and oxygen.If least intake air required for complete combustion flows into combustion chamber by controlling

EGR gas(contains no oxygen) which is recirculated to combustion chamber, NOx decreases

because there is no supplementary oxygen to react with nitrogen.

DTC DESCRIPTION

P0103 is set when MAFS singal line voltage is above 5.0V(above 1000mg/stroke). This code is due to 1)

short in ground circuit or 2)short to battery in singal or power circuit 3)MAFS component failure.

DTC DETECTING CONDITION

Item

Threshold Value

Fail Safe

Detecting Condition

MAFS output value above 1000mg/stroke

(OC/SC+)

EGR control inhibited

ECM calcultaes mass air flow using

engine speed data

Check

lamp

NO

Possible Cause

MAFS circuit

MAFS component

OC (Open Circuit) : Open, SC- (Short Circuit - ) : Short to ground , SC+ (Short Circuit +) : Short to

batterySIGNAL WAVEFORM AND DATA

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MAFS waveform looks like saw teeth at idle. This waveform is displayed because intake pulse is

sensed at MAFS .(because there is no throttle valve at diesel engine.) Therefore, this waveform is

correct.

SPECIFICATION

Air flow

Voltage

Air flow

Voltage

10 Kg/h

1.23V

250 Kg/h

3.47V

15 Kg/h

1.37V

370 Kg/h

3.97V

30 Kg/h

1.70V

480 Kg/h

4.23V

60 Kg/h

2.18V

640 Kg/h

4.61V

120 Kg/h

2.75V

SCHEMATIC DIAGRAM

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MONITOR SCANTOOL DATA

1.Connect Scantool to Data Link Connector (DLC).

2.Warm engine up to normal operating temperature.3.Turn "OFF" electrical devices and A/C.

4.Monitor "AIR FLOW VOLTAGE" and "EGR VALVE CONTROL PWM" displayed on Scantool.

Specification : When EGR actuator do not operate(EGR actuator duty 5%) : 2.0~2.5V

average

When EGR actuator operates(EGR actuator duty 95%) : 1.5~2.2V average

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TERMINAL AND CONNECTOR INSPECTION

1.Electrical systems consist of a lot of harness and connectors, poor connection of terminals can cause

various problems and damage of component.2.Perform checking procedure as follows.

(1) Check damage of harness and terminals : Check terminals for contact resistance, corrosion and

deformation.

(2) Check connecting condition of ECM and component connector : Check terminal seperation,

damage of locking device and connecting condition between terminal and wiring.

Disconnect the pin which requires checking at mail connector and insert it to the terminal at

female connector for checking connecting condition. ( after checking, reconnect the pin at

correct position )

3. Is the problem found?

Repair the trouble causing part and go to "Verification of Vehicle Repair".

Go to "Power Circuit Inspection".

POWER CIRCUIT INSPECTION

1. IG KEY "OFF", ENGINE "OFF"

2. Disconnect MAFS connector.

3. IG KEY "ON"4.Check the voltage or MAFS connector terminal 2 and 4.

Specification : terminal 2 : 4.8V~5.1V

terminal 4 : 11.5V~13.0V

5. Is the measured voltage within the specification?

Go to "Signal Circuit Inspection".

When output voltage is not detected at terminal 2 :Repair open between MAFS connector terminal 2 and ECM connector(C06-2) terminal 45 and go

to "Verification of Vehicle Repair".

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en ou pu vo age s no e ec e a erm na :

Repair open in FAM 15A INJ FUSE and related circuit, and go to "Verification of Vehicle Repair".

SIGNAL CIRCUIT INSPECTION

1.Check open in signal circuit

(1) IG KEY "OFF", ENGINE "OFF"

(2) Disconnect MAFS connector and ECM connector.

(3) Check continuity between MAFS connector terminal1 and ECM connector terminal 46.

Specification : Continuity( below 1.0)

(4) Is the measured continuity within the specification?

Go to "2. Check short to battery in signal circuit" as follows.

Repair open in signal circuit and go to "Verification of Vehicle Repair".

2.Check short to battery in signal circuit

(1) IG KEY "OFF", ENIGINE "OFF"

(2) Disconnect MAFS connector and ECM connector.

(3) IG KEY "ON"

(4) Measure the voltage of MAFS connector terminal 1.

Specification : 0.0V~0.1V

(5) Is the measured voltage within the specification?

Go to "Ground Circuit Ins ection".5/7


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2009 >D 2.9 WGT >Mass Air Flow Sensor (MAFS) >P0103 .

Repair short to battery in signal circuit and go to "Verification of vehicle Repair".

GROUND CIRCUIT INSPECTION

1. IG KEY "OFF", ENGINE "OFF"2. Disconnect MAFS connector.

3. IG KEY "ON"

4.Measure the voltage of MAFS connector terminal 2. [ TEST "A" ]

5.Check the voltage between MAFS connector terminal 2 and 3. [ TEST "B" ]

( terminal 2 : Check + prove , terminal 3 : Check - prove )

Specification : [TEST "A"] Voltage - [TEST "B"] Voltage = below 200mV

6. Is the measured voltage within the specification? (Is ground circuit grounded correctly?)

Go to"Component Inspection".

When "B" voltage is not detected : Repair open in ground circuit and go to "Verification of Vehicle

Repair".

When the voltage difference between "A" and "B" is above 200mV : Eliminate the causes of

excessive resistance and go to "Verification of Vehicle Repair".

COMPONENT INSPECTION

1. IG KEY "OFF", ENGINE "OFF"

2.Check that AFS is installed in correctly according to the direction of arrow on AFS assy'.

3.Check contamination of air cleaner filter.

4. IG KEY "ON", ENGINE "ON"

5.Let IDLE RPM last after warming engine up.

6.Check the leakage of intake system(the leakage or damage of intercooler).

7.Check that EEGR actuator does not operate.

( EEGR actuator turns "OFF" 68 sec. after rapid acceleration. Disconnect EEGR actuator connector

if needed. )

8.Monitor signal voltage of MAFS when engine speed lasts at approx. 800RPM.

Specification : signal voltage fluctuatess between 2.0 and 2.5V.

9. Is the measured voltage within the specification?

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Go to "Verification of Vehicle Repair".

Replace MAFS assy' and go to "Verification of Vehicle Repair".

VERIFICATION OF VEHICLE REPAIRAfter a repair, it is essential to verify that the fault is corrected.

1.After connecting Scantool select "DIAGNOSTIC TROUBLE CODES(DTCs)" mode.

2.Clear recorded DTC using Scantool.

3.Drive the vehicle within DTC "Enable conditions" in "General information".

4.After selecting "DIAGNOSTIC TROUBLE CODES(DTCs)" mode and check if DTC is recorded again.

5.Are any DTCs recorded ?

Go to the DTC guide of recorded NO. in Scantool.

System operates within specification.

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Check Maf Kia Carnival Diesel