Isuzu Amigo / Axiom / Trooper / Rodeo / VehiCross. Manual - part 1305

6E1–296

RODEO Y22SE 2.2L ENGINE DRIVEABILITY AND EMISSION

DTC P0481  Cooling Fan 2 Control Circuit Malfunction

  (Cont'd)

Step

No

Yes

Value(s)

Action

6

1. Ignition OFF.
2. Disconnect the Powertrain Control Module (PCM)

connectors from the PCM.

3. Check the Low Fan Relay control circuit between

the PCM and Underhood Electrical Center for the
following conditions:

D

A short to ground

D

An open circuit

D

A short to voltage

Was the problem found?

—

Verify repair

Go to Step 7 

7

1. Reinstall the High Fan Relay.
2. Using a fused jumper, ground the High Fan Relay

control circuit at the PCM connector.

3. Ignition ON, Engine OFF.

Does the fan run at High speed?

—

Go to Step 9 

Go to Step 8 

8

Replace the High Fan Relay.

Is the action complete?

—

Verify repair

—

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.

Verify repair.

—

—

—

6E1–297

RODEO Y22SE 2.2L ENGINE DRIVEABILITY AND EMISSION

DIAGNOSTIC TROUBLE CODE (DTC) 

P0502 VEHICLE SPEED SENSOR (VSS) CIRCUIT LOW INPUT

060R100043

Circuit Description

The vehicle speed sensor has a magnet rotated by the
transmission output shaft. Attached to the sensor is a hall
effect circuit that interacts with the magnetic field created
by the rotating magnet. A 12–volt operating supply for the
speed sensor hall circuit is supplied from the meter fuse.
The VSS pulses to ground the 5–volt signal sent from the
powertrain control module (PCM) on the reference circuit.
The PCM interprets vehicle speed by the number of
pulses to ground per second on the reference circuit.
DTC P0502 is a type B code.

Conditions for Setting the DTC

D

Engine is running.

D

Engine coolant temperature is above 60

°

C (140

°

F).

D

System voltage is between 10 and 16 volts.

When the above conditions are met, one of the following
tests will run:

Decel Test

D

MAP is less than 35 kPa.

D

Throttle Position is less than 0.8%.

D

Engine Speed is between 1500 RPM and 3500 RPM.

The Decel Test will fail if vehicle speed is less than 8 km/h
(5mph).

The Decel Test will pass if vehicle speed is greater than 24
km/h (15mph).

Power Test

D

MAP is greater than 70 kPa.

D

Throttle Position is between 25% and 70%.

D

Engine Speed is between 2200 RPM and 4400 RPM.

The Power Test will fail if vehicle speed is less than 8 km/h
(5 mph).
The Power Test will pass if vehicle speed is greater than
8km/h (5mph) without any VSS DTC’s present, or if
vehicle speed is greater than 49 km/h (30mph) with VSS
Diagnostic Trouble Codes present.

Action Taken When the DTC Sets

D

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

D

Base shift logic on RPM only.

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 the MIL OFF on the third consecutive
trip cycle during which the diagnostic has been run and
the fault condition is no longer present.

D

A history Diagnostic Trouble Code P0502 will clear
after 40 consecutive warm–up cycles have occurred
without a fault.

6E1–298

RODEO Y22SE 2.2L ENGINE DRIVEABILITY AND EMISSION

D

Diagnostic Trouble Code P0502 can be cleared by
using the Scan Tool’s ”Clear Info” function.

Diagnostic Aids

D

Poor connection at PCM: Inspect harness connectors
for backed out terminals, improper mating, broken

locks, improperly formed or damaged terminals, and
poor terminal to wire connection.

D

Damaged harness: Inspect the wiring harness to the
EVAP vent solenoid, the EVAP purge solenoid, and the
fuel tank pressure sensor for an intermittent open or
intermittent short circuit.

DTC P0502 – VSS Circuit Low Input

 

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. Ignition OFF.
2. Disconnect the VSS connector.
3. Using a test light to battery +, probe the connector

ground wire.

Did the light illuminate?

—

Go to Step  4 

Go to Step 3 

3

Repair the open in the sensor ground circuit.

—

Verify repair

—

4

1. Ignition ON, sensor disconnected.
2. Using a Digital Voltmeter (DVM), measure at the

VSS connector between ground and voltage
supply.

Was the measurement near the specified value?

Battery

voltage

Go to Step  6 

Go to Step 5 

5

Repair the open or short to ground in the VSS sensor
circuit.

—

Verify repair

—

6

1. Ignition OFF.
2. Check the BLU/BLK wire between the VSS sensor

connector and the PCM for the following conditions:

D

An open circuit

D

A short to ground

Was the faulty condition located?

—

Verify repair

Go to Step 9 

7

Using a DVM, measure the resistance between the
VSS sensor body and transmission case (ground).

Is the resistance above the specified value?

10 K 

W

Verify repair

Go to Step 9 

8

1. Remove the VSS from the transmission case.
2. Visually inspect the VSS for damage.

Does the VSS appear to be OK?

—

Verify repair

—

9

Replace the VSS.

—

Verify repair

—

10

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?

—

Verify repair

—

6E1–299

RODEO Y22SE 2.2L ENGINE DRIVEABILITY AND EMISSION

DIAGNOSTIC TROUBLE CODE (DTC) 

P0506 IDLE CONTROL SYSTEM RPM LOWER THAN EXPECTED

060R100025

Circuit Description

The powertrain control module (PCM) controls engine
idle speed by adjusting the position of the idle air control
(IAC) motor pintle. The IAC is a bi–directional stepper
motor driven by two coils. The PCM applies current to the
IAC coils in steps (counts) to extend the IAC pintle into a
passage in the throttle body to decrease air flow. The
PCM reverses the current to retract the pintle, increasing
air flow. This method allows highly accurate control of idle
speed and quick response to changes in engine load. If
the PCM detects a condition where too low of an idle
speed is present and the PCM is unable to adjust idle
speed by increasing the IAC counts, DTC P0506 will set,
indicating a problem with the idle control system.  DTC
O0506 is a type B code.

Conditions for Setting the DTC

D

No intrusive tests being run.

D

Engine run time is more than 360 seconds.

D

No TPS, VSS, ECT, EGR, MAP, IAT, misfire, low
voltage, fuel system CKP, Injector, O

2

 Sensor, VSS or

canister purge Diagnostic Trouble Codes are set.

D

Barometric pressure is greater than 72.7 kPa.

D

Canister purge duty cycle is above 0%.

D

Engine coolant temperature (ECT) is above 50

°

C

(122

°

F).

D

Intake air temperature above –40

°

C (–40

°

F).

D

MAP is less than 60 kPa.

D

Ignition voltage is between 9.5 volts and 16 volts.

D

The throttle is closed.

D

All conditions are met for 10 seconds.

D

Engine speed is at least 100 RPM lower than desired
idle, based upon  PCM expectations.

Action Taken When the DTC Sets

D

The PCM will illuminate the malfunction indicator lamp
(MIL) after the second consecutive trip in which the
fault is detected.

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

Diagnostic Trouble Code P0506 can be cleared by
using the Scan Tool’s ”Clear Info” function.

Diagnostic Aids

Check for the following conditions:

D

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