Maitenance Schedule; Visual/Physical Engine Compartment Inspection; Basic Knowledge Of Tools Required; Seral Data Communications - Isuzu 1999 RODEO Workshop Manual

6E2–30
RODEO 6VD1 3.2L ENGINE DRIVEABILITY AND EMISSIONS

Maitenance Schedule

Refer to the Maintenance Schedule .
Visual/Physical Engine Compartment
Inspection
Perform a careful visual and physical engine
compartment inspection when performing any diagnostic
procedure or diagnosing the cause of an emission test
failure. This can often lead to repairing a problem without
further steps. Use the following guidelines when
performing a visual/physical inspection:
f Inspect all vacuum hoses for pinches, cuts,
disconnections, and proper routing.
f Inspect hoses that are difficult to see behind other
components.
f Inspect all wires in the engine compartment for proper
connections, burned or chafed spots, pinched wires,
contact with sharp edges or contact with hot exhaust
manifolds or pipes.

Basic Knowledge of Tools Required

NOTE: Lack of basic knowledge of this powertrain when
performing diagnostic procedures could result in an
incorrect diagnosis or damage to powertrain
components. Do not attempt to diagnose a powertrain
problem without this basic knowledge.
A basic understanding of hand tools is necessary to effec-
tively use this section of the Service Manual.

Seral Data Communications

Class II Serial Data Communications

Government regulations
manufacturers establish a common communication
system. This vehicle
communication system. Each bit of information can have
one of two lengths: long or short. This allows vehicle
wiring to be reduced by transmitting and receiving
multiple signals over a single wire. The messages carried
on Class II data streams are also prioritized. If two
messages attempt to establish communications on the
data line at the same time, only the message with higher
priority will continue. The device with the lower priority
message must wait. The most significant result of this
regulation is that it provides Tech 2 manufacturers with
the capability to access data from any make or model
vehicle that is sold.
The data displayed on the other Tech 2 will appear the
same, with some exceptions. Some scan tools will only
be able to display certain vehicle parameters as values
that are a coded representation of the true or actual value.
For more information on this system of coding, refer to
Decimal/Binary/Hexadecimal Conversions. On this
vehicle the Tech 2 displays the actual values for vehicle
parameters. It will not be necessary to perform any
conversions from coded values to actual values.
require that all vehicle
utilizes the "Class

On-Board Diagnostic (OBD II)

On-Board Diagnostic Tests

A diagnostic test is a series of steps, the result of which is
a pass or fail reported to the diagnostic executive. When
a diagnostic test reports a pass result, the diagnostic
executive records the following data:
f The diagnostic test has been completed since the last
ignition cycle.
f The diagnostic test has passed during the current
ignition cycle.
f The fault identified by the diagnostic test is not
currently active.
When a diagnostic test reports a fail result, the diagnostic
executive records the following data:
f The diagnostic test has been completed since the last
ignition cycle.
f The fault identified by the diagnostic test is currently
active.
f The fault has been active during this ignition cycle.
f The operating conditions at the time of the failure.
Remember, a fuel trim DTC may be triggered by a list of
vehicle faults. Make use of all information available (other
DTCs stored, rich or lean condition, etc.) when
diagnosing a fuel trim fault.
Comprehensive Component Monitor
Diagnostic Operation
Comprehensive component monitoring diagnostics are
required to monitor emissions-related input and output
powertrain components.
Comprehensive
Components Intended To illuminate MIL is a list of
components, features or functions that could fall under
this requirement.
II"
Input Components:
Input components are monitored for circuit continuity and
out-of-range values. This includes rationality checking.
Rationality checking refers to indicating a fault when the
signal from a sensor does not seem reasonable,
i.e.Throttle Position (TP) sensor that indicates high
throttle position at low engine loads or MAP voltage. Input
components may include, but are not limited to the
following sensors:
f Vehicle Speed Sensor (VSS)
f Transmission Output Speed Sensor (TOSS)
f Crankshaft Position (CKP) Sensor
f Knock Sensor (KS)
f Throttle Position (TP) Sensor
f Engine Coolant Temperature (ECT) Sensor
f Camshaft Position (CMP) Sensor
f Manifold Absolute Pressure (MAP) Sensor
f Mass Air Flow (MAF) Sensor
The CARB
Component Monitoring
OBD II
List Of