SsangYong Musso. Manual - part 125

1F-84 ENGINE CONTROLS

SSANGYONG Y158

Circuit Description

The heated element on the hot-film air mass meter is a
platinum film resistor (heater). It is located on a ceramic
plate together with the other elements in the bridge cir-
cuit. The temperature sensitive resistor (flow sensor) also
included in the bridge. The separation of heater and flow
sensor facilitates design of the control circuitry.  Saw
cuts are employed to ensure thermal decoupling
between the heating element and the intake air temper-
ature sensor. The complete control circuitry is located
on a single layer. The voltage at the heater provides the
index for the mass air flow. The hot film air mass me-
t e r ’ s  electronic circuitry then converts the voltage to a
level suitable for processing in the engine control mod-
ule (ECM). This device does not need a burn off pro-
cess to maintain its measuring precision over an
extended period. In recognition of the fact that most de-
posits  collect on the sensor element’s leading edge,
the  essential thermal transfer elements are located
downstream on the ceramic layer. The sensor element
is also designed to ensure that deposits will not influence
the flow pattern around the sensor.

Conditions for Setting the DTC

•••••

Load threshold is less than 0.02.

•••••

No fault of engine speed.

•••••

Start end reached.

DIAGNOSTIC TROUBLE CODE (DTC) P0102

MASS AIR FLOW LOW VOLTAGE (3.2L DOHC)

Action Taken When the DTC Sets

•••••

The Malfunition Indicator Lamp (MIL) will illuminate
after two consecutive driving cycles in which the diag-
nostic runs with the fault active.

•••••

The ECM will record operating conditions at the time
the diagnostic fails. This information will be stored in
the Freeze Frame and Failure Records buffers.

•••••

A history DTC is stored.

Conditions for Clearing the MIL/DTC

•••••

The Malfunction Indicator Lamp (MIL) will turn off af-
ter three consecutive driving cycles in which the diag-
nostic runs without a fault.

•••••

A history DTC will clear after 40 consecutive warm-
up cycles without a fault.

•••••

The DTC(s) can be cleared by using the scan tool.

Diagnostic Aids

An intermittent may be caused by a poor connection,
misrouted harness, rubbed through wire insulation, or a
wire broken inside insulation.

For the load limit monitoring a calculated, which is
proportional to the sensor output voltage, is compared
with on upper threshold value continuously. As soon as
the diagnosis load exceeds the limit, a fault code P0102
is set.

YAA1F580

ENGINE CONTROLS 1F-85

SSANGYONG Y158

Test Description

The number(s) below refer to specific step(s) on the
diagnostic table.

1. Euro On-Board Diagnostic (EOBD) System Check

prompts the technician to complete some basic
checks and store the freeze frame and failure re-
cords data on the scan tool if applicable. This

creates an electronic copy of the data taken when
the malfunction occurred. The information is then
stored on the scan tool for later reference.

13. The replacement ECM must be reprogrammed. Re-

fer to the latest Techline procedure for ECM repro
gramming.

Step

Action

Value(s)

Yes

DTC P0102 Mass Air Flow Low Voltage (3.2L DOHC)

Go to Step 2

Go to “Euro

On-Board

Diagnostic

System Check”

10 v

Go to Step 7

Go to Step 11

Go to Step 9

Go to Step 12

1.3 - 1.7 v at

Idle

Go to Step 4

Go to Step 5

Perform the Euro On-Board Diagnostic (EOBD) System
Check.
Is the system check complete?

1.  Turn the ignition ON, with the engine OFF.
2.  Install a scan tool.
3.  Using the scan tool, select Engine Data Display.
Does the scan tool display “Mass Air Flow Meter”
between the specified values?
1. Operate engine at normal temperature.
2. With engine at idle, the scan tool should indicate a

“Mass Air Flow Meter” reading at the specified value

Is the reading at the specified value?
1. Turn the ignition ON, with the engine OFF.
2. Review the Freeze Frame data and note the

parameters.

3. Operate the vehicle within the Freeze Frame conditions

and Conditions for Setting the DTC as noted.

Does the scan tool display Mass Air Flow (MAF) voltage
below the specified value?
1. Turn the ignition OFF.
2. Disconnect MAF sensor.
3. Turn the ignition ON.
4. With a test light connected to the ground, probe the

MAF sensor circuit terminal 2.

Does the test light illuminate?
Measure voltage between MAF sensor harness
connector terminal 2 and 3.
Is voltage greater than specified value?
Measure voltage at MAF sensor harness connector
terminal 4 with Digital Voltmeter to ground.
Is voltage near the specified value?
With a test light connected to the battery, prove the
MAF sensor signal circuit terminal 5.
Does the test light illuminate?
Check the MAF sensor signal circuit for an open or
short to ground and repair as necessary.
Is a repair necessary?

0.9 - 1.1 v

Go to Step 3

Go to Step 5

0.2 v

Go to Step 5

Go to

"Diagnostic

Aids"

Go to Step 6

Go to "Over

Voltage

Protection

Relay (OVPR)

Circuit Check"

Go to Step 14

Go to Step 13

5 v

Go to Step 8

Go to Step 10

1F-86 ENGINE CONTROLS

SSANGYONG Y158

Check the 5 volts reference circuit for an open or short
to ground and repair as necessary.
Is a repair complete?
Check the MAF sensor ground circuit for an open and
repair as necessary.
Is a repair complete?
1. Turn the ignition OFF.
2. Replace the MAP sensor.
Is the action complete?
1. Turn the ignition OFF.
2. Replace the Engine Control Module (ECM).
Is the action complete?
1. Using the scan tool, clear the Diagnostic Trouble

Codes (DTCs).

2. Start the engine.
3. Operate the vehicle within the conditions for setting

this DTC as specified in the supporting text.

Does the scan tool indicate that this diagnostic has ran
and passed?
Check if any additional DTCs are set.
Are any DTCs displayed that have not been diagnosed?

Step

Action

Value(s)

Yes

Go to Step 14

Go to Step 13

Go to Step 14

Go to Step 13

Go to Step 14

DTC P0102 Mass Air Flow Low Voltage (3.2L DOHC) (Cont'd)

Go to

applicable

DTC table

System OK

Go to Step 15

Go to Step 2

ENGINE CONTROLS 1F-87

SSANGYONG Y158

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