HOLDEN GEN III V8, Service Training

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GEN III V8 ENGINE MANAGEMENT
On vehicles fitted with a GEN III V8, the devices (control modules) the BCM polls are
• Power-train Interface Module (PIM)
• Instrument cluster (INS)
• Antilock Brake/Electronic Traction Control System (ABS/ETC) Module
• Supplemental Restraint System (SRS) Sensing and Diagnostic Module (SDM)
• Electronic Climate Control (ECC) Module
• TECH2
The data provided by each device may be utilised by any device connected to the bus
Each device has a unique response Message Identifier Word (MIW) for ease of identification
The bus master (BCM) polls each device with a serial data message which includes that devices MIW The
device responds by putting a serial data message onto the bus which includes its MIW and data, of which is
retrieved and utilised by any device requiring it
The BCM polls each device for a status update, once every 300 milliseconds The exception to this being the
PIM (GEN III V8) which is polled twice every 300 milliseconds The PIM will construct a serial data message
from information requested from the PCM via the Class 2 communication This constructed serial data message
is then placed on the serial data bus
When the ignition switch is turned from the OFF position to the ON position, the BCM will communicate with the
PCM via the PIM for theft deterrent purposes If the BCM does not receive an OK TO START message from the
PIM within 0 5 seconds of ignition on, the auxiliary data bus is isolated via switching from the BCM
The isolation of the auxiliary data bus during this period eliminates the possibility of a device failure other than
the BCM, or PIM, causing a problem on the serial data bus and inhibiting theft deterrent communications
This period (short loop time) continues until the PIM responds with an acknowledgment or for a maximum of five
seconds after which the BCM will switch to the standard polling sequence and a no start condition will occur
Following successful theft deterrent communications, the BCM begins sequential polling of devices on the bus
and normal system operation is established
When the ignition switch is in the OFF position, the BCM continues to poll, allowing for TECH 2 communications
and external control of the bus prior to the ignition being switched on
Starter Relay
The PIM also controls the operation of the starter relay When the ignition switch is turned to on, the PIM will
enable the starter relay for one second, if the PIM does not receive the correct security code it will disable the
starter relay If the PIM receives the correct security code from the BCM, the PIM will continue to enable the
start relay Once the engine has started and the engine speed is above 500 RPM the PIM will disable the starter
relay, preventing starter engagement while the engine is running
If the serial data bus between the BCM and the PIM should fail (no polling from the BCM for more than 1 0
minutes) after successful theft deterrent communications, the PIM will allow subsequent starts, however there
will be a crank delay of one second If the PIM receives valid communication, normal operation will resume
If the Class II serial data bus between the PIM and the PCM should fail (no communications for 20 seconds)
after successful theft deterrent communications, the PCM will allow subsequent starts, however there will be a
crank delay of one second If communications between the PCM and the PIM are re-established, normal
operation will resume
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