Isuzu Trooper (2000 year). Manual - part 322

6E–417

TROOPER 6VE1 3.5L ENGINE DRIVEABILITY AND EMISSIONS

If it is determined that the DTC occurs
intermittently,performing the DTC

P1120 Diagnostic Chart may isolate the cause of the fault.

DTC P1220-TPS 2 Circuit Fault

 

Step

Action

Value(s)

Yes

No

1

Was the “On-Board (OBD) System Check” performed?

—

Go to

 Step 2

Go to

 OBD

System

Check

2

Was the “Electric Throttle Control (ETC) System
Check” performed?

—

Go to

 Step 3

Go to

 ETC

System

Check

3

1. Ignition “ON”, engine not running.
2. Observe the MAP reading on the Tech 2.

Is the MAP reading less than the specified value?

65 kPa

Go to

 Step 4

Go to

 Step 7

4

1. Disconnect the MAP sensor.
2. Connect a test 5 volt reference circuit and the MAP

signal at the MAP sensor harness connector.

3. Observe the MAP reading on the Tech 2.

Is the MAP reading less than the specified value? (If no,
start with diagnosis chart for other sensors in the circuit
and see if 5V returns.)

—

Go to

 Step 6

Go to

 Step 5

5

1. Check the MAP signal circuit between the PCM and

MAP ground circuit.

2. If the MAP signal circuit is open or shorted, repair as

necessary.

Was the MAP signal circuit open or shorted?

—

Verify repair

Go to

 Step 13

6

Replace the MAP sensor.

Is the action complete?

—

Verify repair

—

7

Observe the TP angle reading on the Tech-2 while
slowly opening the throttle.

Does the TP angle increase steadily and evenly from
the closed throttle value to the wide open  throttle
value?

Closed TP

sensor 1 =8 

∼

10 % TP

sensor 2 =90

∼

 92 % Wide

open TP

sensor 1 =90

∼

 92 % TP

sensor 2 =8 

∼

10 %

Refer to

Diagnostic

Aids

Go to

 Step 8

8

1. Disconnect the TP sensor.
2. Observe the TP sensor reading on the Tech2.

Is the TP sensor reading near the specified value?

0V

Go to

 Step 9

Go to

 Step 10

9

1. Connect a test light between the 5Volt reference

circuit and the TP2 sensor signal circuit at the
TPsensor harness connector.

2. Observe the TP sensor reading on the Tech 2.

Is the TP sensor reading near the specified value?

5V

Go to

 Step 12

Go to

 Step 11

6E–418

TROOPER 6VE1 3.5L ENGINE DRIVEABILITY AND EMISSIONS

DTC P1220-TPS 2 Circuit Fault

  (Cont'd)

Step

No

Yes

Value(s)

Action

10

Check the following items;

1. TP2 signal circuit for a short to voltage.
2. TP2 sensor ground circuit for high resistance

between the PCM and the TP2 sensor.

3. TP2 sensor ground circuit for a poor connection.
4. If a problem is found,repair wiring harness as

necessary.

Was a problem found?

—

Verify repair

Go to

 Step 13

11

Check the following items;

1. TP2 signal circuit or 5 volt reference circuit for a

poor connection.

2. TP2 signal circuit or 5 volt reference circuit for high

resistance between the PCM and the TP sensor.

3. If a problem is found, repair wiring harness as

necessary.

Was a problem found?

—

Verify repair

Go to

 Step 13

12

Replace the TP sensor.

Is the action complete?

—

Verify repair

—

13

Replace the PCM.

IMPORTANT: The replacement PCM must be
programmed. Refer to

 ON-Vehicle Service in Power

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 replasement PCM.

Is the action complete?

—

Verify repair

—

6E–419

TROOPER 6VE1 3.5L ENGINE DRIVEABILITY AND EMISSIONS

Diagnosis Truble Code(DTC) 

P1221 TPS1 – TPS2 correlation(Circuit Performance)

D06RY00157

Circuit Description

D

The powertrain control module (PCM) controls engine
speed by adjusting the position of the throttle control
valve (DC motor). The throttle motor is a DC motor
driven by one coil. The PCM applies current to  DC
motor coil in steps (%) to adjustment the  valve into a
passage in the throttle body to air flow.

This method allows highly accurate control of
engine speed and quick response to changes in
engine load.

D

The acceleration position (AP) sensor circuit provides
a voltage signal relative to acceleration pedal angle.

The acceleration pedal angle (AP1) will vary about
13% at idle position to about 87% at open
throttle(WOT).

APS signal is used to determine which DC will
adjusting throttle position.

After the APS signal has been processed by the
PCM, it will command DC motor to allow a move
of throttle position.

D

Acceleration pedal – Check for objects blocking the AP
sensor or pedal arm with spring, and excessive
deposits in the acceleration pedal arm and on the
acceleration pedal.

Test Description

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

2. Visually/physically inspect for the following throttle

valve conditions.

3.Visually/physically inspect for the following

acceleration pedal conditions.

5.Check the following circuits for throttle valve and DC

moter. Check the following TP sensor resistance
and DC motor.

7.Check the following circuits for acceleration pedal.

Check the following AP sensor resistance.

9.Following DTC: Software detect Error for ETC

system.

10.Following DTC: Software detect Error for ETC

system.

Diagnostic Aids

D

An intermittent may be caused by a poor connection,
rubbed–through wire insulation or a wire broken inside
the insulation. Check for poor connections or a
damaged harness. Inspect the PCM harness and
connector for improper mating, broken locks,
improperly formed or damaged terminals, poor
terminal-to-wire connection,

and 

damaged

harness.

D

Throttle body – Check for objects blocking the DC
motor or throttle bore, excessive deposits in the ETC
passage and on the valve spring, and excessive
deposits in the throttle bore and on the throttle valve
plate.

6E–420

TROOPER 6VE1 3.5L ENGINE DRIVEABILITY AND EMISSIONS

 Diagnosis Truble Code(DTC) 

P1221 TPS1 – TPS2 correlation(Circuit Perfoemance)

 

Step

Action

Value(s)

Yes

No

1

Was the “On-Board (OBD) System Check”performed?

—

Go to 

Step 2

Go to 

OBD

System

Check

2

Was the “Electric Throttle Control (ETC) System
Check” performed?

—

Go to 

Step 3

Go to 

ETC

System

Check

3

Visually/physically inspect for the following conditions:

D

Throttle body tampering.

D

Restricted intake throttle system. Check for a
possible  collapsed air intake duct, restricted air
filter  element, or foreign objects blocking the air
intake  system.

D

Throttle body: Check for objects blocking the
throttle  passage or throttle bore, excessive
deposits in  the throttle passage and on the
throttle valve, and  excessive deposits in the
throttle bore and on the  throttle plate.

D

Throttle body with lever: Check for objects send
round  the throttle spring lever that lever is smooth
movement,  and spring lever has not excessive
play

Do any of the above require a repair?

—

Refer to

appropriate

section for

on–vehicle

service

Go to 

Step 5

4

Visually/physically inspect for the following conditions:

D

Acceleration pedal tampering.

D

Acceleration pedal : Check for objects blocking
the spring or pedal arm.

D

Acceleration pedal : Check for objects move the
acceleration pedal that pedal is smooth
movement, and acceleration pedal arm has not
excessive play.

Do any of the above require a repair?

—

Refer to

appropriate

section for

on–vehicle

service

Go to 

Step 5

5

1.  Check for a poor connection at the throttle body

harness connector.

2.  Check for a poor connection at the acceleration

position sensor harness connector.

3.  If a problem is found, replace faulty terminals as

necessary.

Was a problem found?

—

Verify repair

Go to 

Step 8

6

1. Check the following circuits for an open, short to

voltage, short to ground, or poor connection at the
PCM:

Throttle position sensor 1 circuit.

Throttle position sensor 2 circuit.

Throttle DC motor circuit.

Throttle position sensor resistance.

Throttle DC motor  resistance.

2. If a problem is found, repair as necessary.

Was a problem found?

Vcc-GND

1–7k

m

SIG-DND

change

resistance 0.3

– 100

m

Verify repair

Go to 

Step 7