PT Cruiser L4-2.4L Turbo VIN 8 (2005)
Each module provides its own bias and termination in order to transmit and receive messages. The bus voltage is at zero volts when no modules are
transmitting and is pulled up to about seven and a half volts when modules are transmitting.
The bus messages are transmitted at a rate averaging 10,800 bits per second. Since there is only voltage present when the modules transmit and the
message length is only about 500 milliseconds, it is ineffective to try and measure the bus activity with a conventional voltmeter. The preferred method
is to use the DRBIII(R) lab scope. The 12 v square wave selection on the 20-volt scale provides a good view of the bus activity. Voltage on the bus
should pulse between zero and about seven and a half volts. Refer to the figure for some typical displays.
The PCI Bus failure modes are broken down into two categories. PCI Bus Communication Failure and individual module no response. Causes of a PCI
Bus Communication Failure include a short to ground or battery on the PCI circuit. Individual module no response can be caused by an open circuit at
the module, or an open battery or ground circuit to the affected module.
Symptoms of a PCI Bus Communication Failure would include but are not limited to:
-
All gauges on the EMIC stay at zero
-
All telltales on EMIC illuminate
-
EMIC backlighting at full intensity
-
No response received from any module on the PCI bus (except PCM/ECM)
-
No start (if equipped with Sentry Key Immobilizer)
Symptoms of individual module failure could include any one or more of the above. The difference would be that at least one or more modules would
respond to the DRBIII(R).
