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SsangYong Musso. Manual - part 146

1F-168 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

the 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?
Is the action complete?

DTC P0137 O2 Bank 1 Sensor 2 Low Voltage (Cont'd)

Go to

applicable

DTC table

System OK

Go to Step 9

Go to Step 2

ENGINE CONTROLS 1F-169

SSANGYONG Y158

BLANK

1F-170 ENGINE CONTROLS

SSANGYONG Y158

DAGNOSTIC TROUBLE CODE (DTC) P0138

O2 BANK 1 SENSOR 2 HIGH VOLTAGE

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 2). The O2S 2 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 2 pigtail wiring, connector, or terminal is
damaged, the entire O2S 2 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 2 wire(s).

Any attempt to repair the wires, connector, or terminal
and degrade the O2S 2 performance.

Conditions for Setting the DTC

•••••

O2S 2 voltage is greater than 1.0 volt (2.3L DOHC).

•••••

O2S 2 voltage is greater than 1.05 volt (3.2L DOHC).

•••••

Lambda control status is enabled.

•••••

P0141; lambda heater status is active/faultless.

•••••

Oxygen sensor heater status 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

Check for the following conditions:

•••••

Rich exhaust - An overly rich exhaust may load the
catalyst, causing high O2S 2 signal voltages.

•••••

Silicone contamination - A false rich condition may
be caused by silicone contamination of the O2S 2.
This will be indicated by a powdery white deposit on
the sensor.

•••••

Faulty O2S 2- If O2S 2 is internally shorted, the O2S
2 voltage displayed on a scan tool will be over 1 volt.
Disconnect the O2S 2 and jumper the sensor low
circuit to engine ground; if the displayed voltage goes
from over 1000 mv to around 450 mv, replace the O2S
2.

•••••

Intermittent test - Observe O2S 2 on the scan tool
while moving related connectors and the wiring har-
ness with the key in the ON position. If the failure is
induced, the O2S 2 display will change. This may
help isolate the location of the malfunction.

YAB1F140

ENGINE CONTROLS 1F-171

SSANGYONG Y158

Step

Action

Value(s)

Yes

DTC P0138 O2 Bank 1 Sensor 2 High Voltage

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 2) voltage above 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.

Is the O2S 2 voltage above the specified value?
1. Turn the ignition switch OFF.
2. Disconnect the O2S 2 electrical connector.
3. Disconnect the Engine Control Module (ECM)

electrical connector.

4. With a Digital Voltmeter (DVM) connected to ground,

probe the O2S 2 high signal circuit, terminal 20.

Does the DVM indicate a voltage of the specified value?
1. Reconnect the ECM electrical connectors.
2. Turn the ignition ON, with the engine OFF.
3. Jumper the high and low circuits at the O2S 2

electrical connector, terminals 1 and 2 to ground.

Does the scan tool indicate the O2S 2 voltage below the
specified value?
Repair the short to voltage in the O2S 2 high circuit.
Is the repair complete?
1. Turn the ignition OFF.
2. Replace the O2S 2.
Is the repair complete?

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 P0138 is the result of

a hard failure or an intermittent condition.

5. Disconnecting the O2S 2 and jumping the sensor

signal circuit and the sensor low circuit to ground
should cause the scan tool to display O2S 2 voltage
below 20 mv (0.02 v). If the signal voltage is still
high, the ECM is malfunctioning.

8. The replacement ECM must be reprogrammed. Re-

fer to the latest Techline procedure for reprogram-
ming.

Go to Step 9

20 mV

(0.02 v)

Go to Step 7

Go to Step 8

0 v (± 0.5 v)

Go to Step 5

Go to Step 6

1050 mV

(1.05 v)

Go to Step 4

Go to Step 9

1050 mV

Go to Step 4

Go to Step 3

Go to Step 2

Go to “Euro

On-Board

Diagnostic

System Check”

Content .. 144 145 146 147 ..