HOLDEN GEN III V8, Обучение по обслуживанию

Страница: 19 / 113

GEN III V8 ENGINE MANAGEMENT
Diagnostic Information
The diagnostic tables and functional checks in the Service Manual are designed to locate a faulty circuit or
component through logic based on the process of elimination. The tables in the Service Manual are prepared
with the understanding that the vehicle:
• Functioned correctly at the time of assembly.
• There are no multiple faults.
• The problem currently exists.
The PCM performs a continual self-diagnosis on certain control functions. The PCM indicates the source of a
fault through the use of Diagnostic Trouble Codes (DTCs). The DTCs are four digit codes (POXXX or P1XXX).
When a fault is detected by the PCM, a DTC will be set and stored in the memory of the PCM and the Check
Powertrain Lamp may illuminate.
Recording Test Results (Diagnostic Executive)
The Diagnostic Executive is a unique segment of the PCM software which is designed to co-ordinate and
prioritise the diagnostic procedures as well as define the protocol for recording and displaying their results. The
main responsibilities of the Diagnostic Executive are:
• DTC Information
DTC Information indicates the status of the diagnostic testing for a specific DTC. It contains information on
pass / fail status of the test, when the diagnostic test failed and if the DTC is requesting the illumination of
the Check Powertrain Lamp.
• Freeze Frame / Failure Records
Freeze frame / failure records are stored any time a diagnostic test fails. The PCM has the ability to store up
to six freeze frame / failure records. When a diagnostic test fails, records are stored in the first fail position. If
a different diagnostic test fails, a second fail record position. Additional failed diagnostic tests for different
DTCs also store fail records until the fail record memory is full. The PCM has the ability to store six freeze
frame / failure records, if more than six DTC freeze frame failure records are stored, the fail records are
replaced on a first in, first out basis.
The freeze frame / failure records data list has 32 parameters for data capture. When a DTC is set, the PCM
will capture all 32 parameters at the time the DTC is logged.
In addition to the regular data list parameters found in the freeze frame / failure records data list, there is
additional information available about the DTC diagnostics:
• First Odometer - Vehicle kilometre value when the DTC failure first recorded.
• Last Odometer - Vehicle kilometre value when the DTC fail is recorded.
• Fail Counter - Number of ignition cycles with failure (DTC was set).
• Pass Counter - Number of ignition cycles with diagnostic passes (DTC was not set again).
• Not Run Counter - Number of ignition cycles without diagnostic run (DTC conditions were not tested).
• System Status
The System Status (I/M Flag) stores information on which diagnostics have run. If a system diagnostic has
run, the system status flag (yes/no) will be set.
• Warm-up Cycles
Records the number of warm-up cycles that have been achieved since the DTC was set.
Page - 1 4 GEN III V8 ENGINE MANAGEMENT