Isuzu Amigo / Axiom / Trooper / Rodeo / VehiCross. Manual - part 1249

6E1–72

RODEO Y22SE 2.2L ENGINE DRIVEABILITY AND EMISSION

POWERTRAIN CONTROL MODULE

(PCM) DIAGNOSIS

014RX002

To read and clear diagnostic trouble codes, use a Tech 2.

901RX031

IMPORTANT:

Use of a Tech 2 is recommended to clear

diagnostic trouble codes from the PCM memory.
Diagnostic trouble codes can also be cleared by turning
the ignition OFF and disconnecting the battery power
from the PCM for 30 seconds. Turning off the ignition and
disconnecting the battery power from the PCM will cause
all diagnostic information in the PCM memory to be
cleared. Therefore, all the diagnostic tests will have to be
re–run.
Since the PCM can have a failure which may affect only
one circuit, following the diagnostic procedures in this
section will determine which circuit has a problem and
where it is.
If a diagnostic chart indicates that the PCM connections
or the PCM is the cause of a problem, and the PCM is
replaced, but this does not correct the problem, one of the
following may be the reason:

D

There is a problem with the PCM terminal
connections. The terminals may have to be removed
from the connector in order to check them properly.

D

EEPROM program is not correct for the application.
Incorrect components or reprogramming the PCM
with the wrong EEPROM program may cause a
malfunction and may or may not set a DTC.

D

The problem is intermittent. This means that the
problem is not present at the time the system is being
checked. In this case, make a careful physical
inspection of all components and wiring associated
with the affected system and refer to the Symptoms
portion of the manual. 

D

There is a shorted solenoid, relay coil, or harness.
Solenoids and relays are turned ON and OFF by the
PCM using internal electronic switches called drivers.
A shorted solenoid, relay coil, or harness will not
damage the PCM but will cause the solenoid or relay
to be inoperative.

6E1–73

RODEO Y22SE 2.2L ENGINE DRIVEABILITY AND EMISSION

MULTIPLE PCM INFORMATION

SENSOR DTCs SET

Circuit Description

The powertrain control module (PCM) monitors various
sensors to determine the engine operating conditions.
The PCM controls fuel delivery, spark advance, and
emission control device operation based on the sensor
inputs.
The PCM provides a sensor ground to all of the sensors.
The PCM applies 5 volts through a pull–up resistor, and
determines the status of the following sensors by
monitoring the voltage present between the 5–volt supply
and the resistor:

D

The Fuel Tank Vapor Pressure Sensor

D

The throttle position (TP) sensor

D

The manifold absolute pressure (MAP) sensor

The PCM provides the following sensors with a 5–volt
reference and a sensor ground signal:

D

The Linear exhaust gas recirculation (EGR) valve

D

The A/C Pressure Sensor

The PCM monitors the separate feedback signals from
these sensors in order to determine their operating
status.

Diagnostic Aids

Be sure to inspect PCM and engine grounds for being se-

cure and clean.

A short to voltage in one of the sensor input circuits may
cause one or more of the following DTCs to be set:

D

P0108/P1106

D

P0113/P1111

D

P0118/P1115

D

P0123/P1121

D

P0463

If a sensor input circuit has been shorted to  voltage, en-

sure that the sensor is not damaged. A damaged sensor

will continue to indicate a high or low voltage after the af-

fected circuit has been repaired. If the sensor has been

damaged, replace it.

An open in the sensor ground circuit between the PCM
and the splice will cause one or more of the following
DTCs to be set:

D

P0108/P1106

D

P0113/P1111

D

P0118/P1115

D

P0123/P01121

D

P0453/P0463

A short to ground in the 5–volt reference A circuit will
cause one or more of the following DTCs to be set:

D

P0107/P1107

D

P0122/P1122

D

P0112/P1112

D

P0117/P1114

D

P0454/P0462

D

P0405

D

P0532

Check for the following conditions:

D

Poor connection at PCM. Inspect the harness
connectors for backed–out terminals, improper
mating, broken locks, improperly formed or damaged
terminals, and a poor terminal–to–wire connection.

D

Damaged harness. Inspect the wiring harness for
damage. If the harness is not damaged, observe an
affected sensor’s displayed value on the Tech 2 with
the ignition ON and the engine OFF while you  move
the connectors and the wiring harnesses related to
the following sensors:

D

IAT

D

ECT

D

TP

D

MAP

D

EGR

D

Fuel Tank Vapor Pressure Sensor

D

A/C Pressure Sensor

6E1–74

RODEO Y22SE 2.2L ENGINE DRIVEABILITY AND EMISSION

Multiple PCM Information Sensor DTCs Set

 

Step

Action

Value(s)

Yes

No

1

Was the ”On–Board Diagnostic (OBD) System Check”
performed?

—

Go to 

Step 2 

Go to 

OBD

System

Check 

2

1. Turn the ignition OFF, disconnect the PCM.
2. Turn the ignition ON, check the 5 volt reference

circuits for the following conditions:

D

A poor connection at the PCM.

D

An open between the PCM connector and the
splice.

D

A short to ground.

D

A short to voltage.

Is there an open or short?

—

Go to 

Step 3 

Go to 

Step 4 

3

Repair the open or short.

Is the action complete?

—

Verify repair

—

4

Check the sensor ground circuit for the following
conditions:

D

A poor connection at the PCM or the affected
sensors.

D

An open between the PCM connector and the
affected sensors.

Is there an open or a poor connection?

—

Go to 

Step 5 

Go to 

Step 6 

5

Repair the open or the poor connection.

Is the action complete?

—

Verify repair

—

6

Measure the voltage between the EGR pintle position
sensor signal circuit at the PCM harness connector and
ground.

Does the voltage measure near the specified value?

0 V

Go to 

Step 7 

Go to 

Step 13

7

Measure the voltage between the MAP sensor signal
circuit at the PCM harness connector and ground.

Does the voltage measure near the specified value?

0 V

Go to 

Step 8 

Go to 

Step 14

8

Measure the voltage between the TP sensor signal
circuit at the PCM harness connector and ground.

Does the voltage measure near the specified value?

0 V

Go to 

Step 9 

Go to 

Step 15

9

Measure the voltage between the IAT sensor signal
circuit at the PCM harness connector and ground.

Does the voltage measure near the specified value?

0 V

Go to 

Step 10

Go to 

Step 16

10

Measure the voltage between the ECT sensor signal
circuit at the PCM harness connector and ground.

Does the voltage measure near the specified value?

0 V

Go to 

Step 20

Go to 

Step 17

11

Measure the voltage between the A/C Pressure
Sensor circut at the PCM harness connector and
ground.

Does the voltage measure near the specified value?

0 V

Go to 

Step 13

Go to 

Step 19

6E1–75

RODEO Y22SE 2.2L ENGINE DRIVEABILITY AND EMISSION

Multiple PCM Information Sensor DTCs Set

  (Cont'd)

Step

No

Yes

Value(s)

Action

12

1. Disconnect the EGR valve.
2. Measure the voltage between the EGR pintle

position sensor signal circuit at the PCM harness
connector and ground.

Does the voltage measure near the specified value?

0 V

Go to 

Step 12

Go to 

Step 17

13

Replace the EGR valve.

Is the action complete?

—

Verify repair

—

14

Locate and repair the short to voltage in the MAP
sensor signal circuit.

Is the action complete?

—

Verify repair

—

15

Locate and repair the short to voltage in the TP sensor
signal circuit.

Is the action complete?

—

Verify repair

—

16

Locate and repair the short to voltage in the IAT sensor
signal circuit.

Is the action complete?

—

Verify repair

—

17

Locate and repair the short to voltage in the ECT
sensor signal circuit.

Is the action complete?

—

Verify repair

—

18

Locate and repair the short to voltage in the A/C
Pressure Sensor circuit.

Is the action complete?

—

Verify repair

—

19

Locate and repair the short to voltage in the EGR pintle
position sensor signal circuit.

Is the action complete?

—

Verify repair

—

20

Replace the PCM.

IMPORTANT: The replacement PCM must be
programmed. Refer to On–Vehicle Service in
Powertrain Control Module and Sensors for
procedures. 

And also refer to latest service bulletin
Check to see if the Latest software is released or not.
And then Down Load the LATEST PROGRAMMED
SOFTWARE to the replacement PCM.

Is the action complete?

—

Go to 

OBD

System

Check 

—