Avenger L4-2.0L DOHC (1995)
Neutral Safety Switch: Description and Operation
NAME OF CODE:
Park/neutral Switch Failure
WHEN MONITORED:
with the transmission in park, neutral, or drive, and the transmission not in limp-in mode.
SET CONDITION:
If the transmision is in park or neutral, the engine must be cranking. If the transmission is in drive, the vehicle speed must be above 50 mph, the
engine speed must be between 1,985 and 4,480 rpm, the TP sensor must not be closed, and the MAP must be above 66% of barometric pressure.
THEORY OF OPERATION:
The park/neutral position switch is used to communicate the state of the transmission to the idle air control (IAC) motor via the PCM. The IAC
motor needs this information in order to determine the target idle speed. The IAC motor holds the idle speed at 600 rpm in park or neutral, while it
increases the engine speed to about 800 rpm when the transmission is shifted into drive. Spark also is advanced in park or neutral position, while it
is retarded in drive position.
POSSIBLE CAUSES:
-
Dirty or melted connector contacts
-
Disconnected wiring harness
-
Park/neutral position switch failure
-
Mechanical transmission problem
-
PCM failure
