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SsangYong Musso. Manual - part 156

1F-208 ENGINE CONTROLS

SSANGYONG Y158

Step

Action

Value(s)

Yes

1. Using the scan tool, clear the Diagnostic Trouble

Codes (DTCs).

2. Start the engine and idle at normal operating

temperature.

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?

Go to Step 11

Go to Step 2

DTC P0155-207 O2 Bank 2 Sensor 3 Heater Short Circuit to Ground or Open

(3.2L DOHC) (Cont'd)

Go to

applicable

DTC table

System OK

ENGINE CONTROLS 1F-209

SSANGYONG Y158

BLANK

1F-210 ENGINE CONTROLS

SSANGYONG Y158

DAGNOSTIC TROUBLE CODE (DTC) P0157

O2 BANK 2 SENSOR 4 LOW VOLTAGE (3.2L DOHC)

Circuit Description

In order to control emissions, a catalytic converter is
used to convert harmful emissions into harmless water
vapor and carbon dioxide.

The Engine Control Module (ECM) has the ability to
monitor this process by using a Heated Oxygen Sensor
(O2S 4). The O2S 4 produces an output signal which
indicates the storage capacity of the catalyst. This in
turn indicates the catalyst’s ability to convert exhaust
emissions effectively.

If the O2S 4 pigtail wiring, connector, or terminal is
damaged, the entire O2S 4 assembly must be replaced.
Do not attempt to repair the wiring, connector, or
terminals. In order for the sensor to function properly, it
must have a clean air reference provided to it. This clean
air reference is obtained by way of the O2S 4 wire(s).

Any attempt to repair the wires, connector, or terminal
and degrade the O2S 4 performance.

Conditions for Setting the DTC

•••••

O2S 4 voltage is less than 0.02 volt for greater than
300 seconds.

•••••

Lambda control status is enabled.

•••••

Injector 1 ~ 6 status is active.

•••••

Lambda pilot control status is active.

•••••

Oxygen sensor heater status is concluded.

Action Taken When the DTC Sets

•••••

The Malfunction 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 MIL will turn off after three consecutive driving
cycles in which the diagnostic runs without a fault.

•••••

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

•••••

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

Diagnostic Aids

An intermittent may be caused by rubbed-through wire
insulation or a wire contacting the exhaust.

•••••

Exhaust system - Inspect the exhaust system for
leaks. Check the exhaust between the three-way cat-
alytic converter and the flange for leaks, corrosion,
or for loose or missing hardware and repair as neces-
sary.

•••••

Poor connection or damaged harness - Ensure that
the O2S 4 pigtail is not contacting the exhaust.

•••••

Check for the following conditions:

•••••

improper mating

•••••

Broken locks

•••••

Improperly formed

•••••

Damaged terminals

•••••

Poor terminal-to-wire connection

•••••

Damaged harness

YAB1F160

ENGINE CONTROLS 1F-211

SSANGYONG Y158

•••••

Intermittent test - Observe the O2S 4 on the scan
tool while moving related connections and the wiring
harness with the ignition ON. If the failure is induced,
the O2S 4 display will change. This may help isolate
the location of the malfunction.

Test Description

Number(s) below refer to the step number(s) on the
Diagnostic Table.

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

Check prompts the technician to complete some
basic checks and store the freeze frame and failure
records 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.

2. This step determines if DTC P0157 is the result of

a hard failure or an intermittent condition.

4. Jumping the O2S 4 low circuit, terminal 2 to ground

is necessary to allow the ECM to display the
supplied bias voltage. If the voltage is between 0.45
and 0.55 volts, then the wiring and the ECM are
OK.

6. The replacement ECM must be reprogrammed. Re-

fer to the latest Techline procedure for reprogram-
ming.

Step

Action

Value(s)

Yes

DTC P0157 O2 Bank 2 Sensor 4 Low Voltage (3.2L DOHC)

Go to Step 2

Go to “Euro

On-Board

Diagnostic

System Check”

Go to Step 8

Perform an 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.
Is the Heated Oxygen Sensor (O2S 4) voltage less than
the specified value?
1. Start the engine.
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?

Is the O2S 4 voltage less than the specified value?
1. Turn the ignition switch OFF.
2. Disconnect the O2S 4 electrical connector.
3. Connect a jumper wire between O2S 4 terminal 2

and ground.

4. Turn the ignition ON, with the engine OFF.
Does the scan tool indicate that the O2S 4 voltage is
within the specified value?
1. Turn the ignition switch OFF.
2. Disconnect the Engine Control Module (ECM)

electrical connectors and check the O2S 4 high
circuit, terminal 26 for a short to ground or short to
the O2S 4 low circuit terminal 25 and repair as
necessary.

Is the repair complete?
1. Turn the ignition OFF.
2. Replace the ECM.
Is the repair complete?
1. Turn the ignition OFF.
2. Replace the O2S 4.
Is the repair complete?

20 mV

(0.02 v)

Go to Step 4

Go to Step 8

20 mV

(0.02 v)

Go to Step 4

Go to Step 3

450 mV -

550 mV

(0.45 v -

0.55 v)

Go to Step 7

Go to Step 5

Go to Step 8

Go to Step 6

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