Isuzu Amigo / Axiom / Trooper / Rodeo / VehiCross. Manual - part 1278

6E1–188

RODEO Y22SE 2.2L ENGINE DRIVEABILITY AND EMISSION

DIAGNOSTIC TROUBLE CODE (DTC) P0201 INJECTOR CIRCUIT 

MALFUNCTION – CYLINDER 1

060R100033

Circuit Description

The powertrain control module (PCM) has four individual
injector driver circuits. Each controls an injector. When a
driver circuit is grounded by the PCM, the injector is
activated. The PCM monitors the current in each driver
circuit. The PCM measures a voltage drop through a fixed
resistor and controls it. The voltage on each driver is
monitored to detect a fault. If the voltage is not what the
PCM expects to monitor on the circuit, a Diagnostic
Trouble Code is set.  This Diagnostic Trouble Code is also
set if an injector driver is shorted to voltage.  DTC P0201
is a type A code.

Conditions for Setting the DTC

D

The battery voltage is more than 9 volts.

D

Engine is running.

D

Fuel pump is ON.

D

The injector voltage does not equal the ignition voltage
when the injector is commanded OFF or the injector
voltage does not equal 0 volts when the injector is
commanded ON.

The above conditions are met for 5 seconds.

Action Taken When the DTC Sets

D

The PCM will illuminate the malfunction indicator lamp
(MIL) the first time the fault is detected.

D

”Open Loop” fuel control will be in effect.

D

The PCM will store conditions which were present
when the Diagnostic Trouble Code was set as Freeze
Frame and in the Failure Records data.

Conditions for Clearing the MIL/DTC

D

The PCM will turn OFF the MIL on the third consecutive
trip cycle in which the diagnostic has been run and the
fault is no longer present.

D

A history Diagnostic Trouble Code P0201 will clear
after 40 consecutive warm–up cycles occur without a
fault.

D

Diagnostic Trouble Code P0201 can be cleared by
using the Scan Tool’s ”Clear Info” function.

Diagnostic Aids

An injector driver circuit that is open or shorted to voltage
will cause a Diagnostic Trouble Code P0201 to set. It will
also cause a misfire due to an inoperative injector. A
misfire Diagnostic Trouble Code will also be set indicating
which cylinder is inoperative.
Long term and short term fuel trims that are excessively
high or low are a good indication that an injector is faulty.
Use Fuel Injector Coil Test Procedure to check for faulty
injectors.

Test Description

Number(s) below refer to the step number(s) on the
Diagnostic Chart:

6E1–189

RODEO Y22SE 2.2L ENGINE DRIVEABILITY AND EMISSION

3.This step determines if Diagnostic Trouble Code

P0201 is the result of a hard failure or an
intermittent condition.

 5. This step tests the harness wiring and PCM control

of the injectors using a test light.

The fuel injector test connector is a gray 5 pin
connector at the right rear of the valve cover. It can
be identified by a blue connector lock which is
tethered to the harness.

J 39021–45 is a test light with one light for each
cylinder. The test light fits on the injector test
connector.

If the test light is ON steady before cranking the
engine as well as while cranking the engine, then the
injector driver circuit is shorted to voltage.

If the test light blinks, the PCM and the wiring to the
injectors are OK. Fuel Injector Coil Test Procedure
will check if the injectors are faulty.

 7. Because the test light was ON steady, voltage to the

injector is OK, but the driver circuit is grounded at all
times. This step determines if the circuit is shorted
to ground or the PCM is faulty.

901RX032

13. Normal injector resistance is slightly more than if

tested directly at the injector because it includes
resistance of the harness wires. The normal value is
about 13.5 

W

.

DTC P0201 – Injector Circuit Malfunction – Cylinder 1

 

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

Will the engine start?

—

Go to Step  3 

Go to Engine

Cranks But

Will Not Run

Chart

3

1. Install the Tech 2. Clear the Diagnostic Trouble

Code.

2. Idle the engine for one minute.

Does Diagnostic Trouble Code P0201 reset?

—

Go to Step  5 

Go to Step  4 

4

1. Review the Freeze Frame data with the ignition ON

and the engine OFF and note the parameters.

2. Operate the vehicle within the Freeze Frame

conditions as noted.

Does P0201 reset?

—

Go to Step  5 

Go to

Diagnostic

Aids 

5

1. Ignition OFF.
2. Disconnect the injector test connector.
3. Install the injector test light J 39021–45 on the

injector test connector.

4. Crank the engine while observing the light for

cylinder 1.

Does the injector test light blink?

—

Go to Fuel

Injector Coil

Test

Procedure 

Go to Step  6 

6

Note whether the injector test light was OFF or ON
steady in step 5.

Was the test light ON steady while cranking the
engine?

—

Go to Step  7 

Go to Step

10 

6E1–190

RODEO Y22SE 2.2L ENGINE DRIVEABILITY AND EMISSION

DTC P0201 – Injector Circuit Malfunction – Cylinder 1

  (Cont'd)

Step

No

Yes

Value(s)

Action

7

1. Disconnect the PCM connector for the affected

injectors.

2. With a test light connected to B+, probe the affected

injector driver circuit.

Does the test light illuminate?

—

Go to Step  8 

Go to Step  9 

8

Repair short to ground in the injector driver circuit.

Is the action complete?

—

Go to OBD

System

Check 

—

9

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 

—

10

1. Disconnect the injector test connector.
2. Ignition ON.
3. Use a test light connected to ground to probe each

terminal on the PCM side of the injector test
connector. Only the Ign+ terminal should illuminate
the test light.

Besides the Ign+, did any other terminal illuminate the
test light?

—

Go to Step

11 

Go to Step

12 

11

Repair the short to voltage in the injector driver circuit.

—

Verify repair

—

12

1. Disconnect the injector test connector.
2. Ignition ON.
3. Use a test light connected to ground to probe each

pin on the injector side of the connector.

Did any terminal illuminate the test light?

—

Go to Step

11 

Go to Step

13 

13

1. Disconnect the injector test connector.
2. Ignition OFF.
3. Clip one lead of an ohmmeter to the ignition pin on

the injector side of the test connector.

4. Touch the other lead to each of the other four  pins in

the test connector, one pin at a time.

Instead of normal injector resistance, did the ohmmeter
indicate an open in one of the injector circuits?

—

Go to Step

14 

Go to Step

15 

14

Repair the open circuit or open injector.

—

Verify repair

—

15

Check for an open circuit between the injector test
connector and the PCM connector for the Injector 1
control circuit.

Was there an open circuit?

—

Go to Step

16 

Go to Step  9 

16

Repair the open circuit.

—

Verify repair

—

6E1–191

RODEO Y22SE 2.2L ENGINE DRIVEABILITY AND EMISSION

DIAGNOSTIC TROUBLE CODE (DTC) P0202 INJECTOR CIRCUIT 

MALFUNCTION – CYLINDER 2

060R100033

Circuit Description

The powertrain control module (PCM) has four individual
injector driver circuits. Each controls an injector. When a
driver circuit is grounded by the PCM, the injector is
activated. The PCM monitors the current in each driver
circuit. The PCM measures a voltage drop through a fixed
resistor and controls it. The voltage on each driver is
monitored to detect a fault. If the voltage is not what the
PCM expects to monitor on the circuit, a Diagnostic
Trouble Code is set. This Diagnostic Trouble Code is also
set if an injector driver is shorted to voltage.  DTC P0202
is a type A code.

Conditions for Setting the DTC

D

The battery voltage is greater than 9 volts.

D

Engine is running.

D

Fuel pump is ON.

D

The injector voltage does not equal the ignition voltage
when the injector is commanded OFF or the injector
voltage does not equal 0 volts when the injector is
commanded ON.

The above conditions are met for 5 seconds.

Action Taken When the DTC Sets

D

The PCM will illuminate the malfunction indicator lamp
(MIL) the first time the fault is detected.

D

”Open Loop” fuel control will be in effect.

D

The PCM will store conditions which were present
when the Diagnostic Trouble Code was set as Freeze
Frame and in the Failure Records data.

Conditions for Clearing the MIL/DTC

D

The PCM will turn OFF the MIL on the third consecutive
trip cycle in which the diagnostic has been run and the
fault is no longer present.

D

A history Diagnostic Trouble Code P0202 will clear
after 40 consecutive warm–up cycles occur without a
fault.

D

Diagnostic Trouble Code P0202 can be cleared by
using the Scan Tool’s ”Clear Info” function.

Diagnostic Aids

An injector driver circuit that is open or shorted to voltage
will cause a Diagnostic Trouble Code P0202 to set. It will
also cause a misfire due to an inoperative injector. A
misfire Diagnostic Trouble Code will also be set indicating
which cylinder is inoperative.
Long term and short term fuel trims that are excessively
high or low are a good indication that an injector is faulty.
Use Fuel Injector Coil Test Procedure to check for faulty
injectors.

Test Description

Number(s) below refer to the step number(s) on the
Diagnostic Chart: