VEHICLE SPEED AND DISTANCE INPUT—PCM
INPUT
On vehicles equipped with an electronic transaxle
(41TE), the transaxle output speed sensor supplies
the vehicle speed and distance inputs to the PCM.
The output speed sensor is located on the side of the
transaxle (Fig. 9).
The speed and distance signals, along with a closed
throttle signal from the TPS, determine if a closed
throttle deceleration or normal idle condition (vehicle
stopped) exists. Under deceleration conditions, the
PCM adjusts the idle air control motor to maintain a
desired MAP value. Under idle conditions, the PCM
adjusts the idle air control motor to maintain a de-
sired engine speed.
VEHICLE SPEED SENSOR—PCM INPUT
Vehicles with 3 speed automatic transaxles or
manual transaxles use vehicle speed sensors. On
both transaxles, the vehicle speed sensor (Fig. 11) is
located on the extension housing. The sensor input is
used by the PCM to determine vehicle speed and dis-
tance traveled.
The vehicle speed sensor generates 8 pulses per
sensor revolution. These signals, along with a closed
throttle signal from the TPS, determine if a closed
throttle deceleration or normal idle condition (vehicle
stopped) exists. Under deceleration conditions, the
PCM adjusts the idle air control motor to maintain a
desired MAP value. Under idle conditions, the PCM
adjusts the idle air control motor to maintain a de-
sired engine speed.
AIR CONDITIONING (A/C) CLUTCH RELAY (AC
BODY)—PCM OUTPUT
The PCM operates the air conditioning clutch relay
ground circuit. The ignition switch supplies battery
power to the solenoid side of the relay. The A/C fan
relay is operated independently of the PCM by the
Fan Cutout switch. When the A/C clutch relay ener-
gizes, battery voltage powers the A/C compressor
clutch.
With the engine operating and the blower motor
switch in the On position, the PCM turns the A/C
clutch on when the A/C switch closes. When the
PCM senses low idle speeds or wide open throttle
through the throttle position sensor, it de-energizes
the A/C clutch relay. The relay contacts open, pre-
venting air conditioning clutch engagement.
On AC body vehicles, the relay is located in the
power distribution center (Fig. 12).
AIR CONDITIONING (A/C) CLUTCH RELAY (AA, AG,
AJ BODY)—PCM OUTPUT
The PCM operates the air conditioning clutch relay
ground circuit. The ignition switch supplies battery
power to the solenoid side of the relay. When the A/C
clutch relay energizes, battery voltage powers the
A/C compressor clutch.
With the engine operating and the blower motor
switch in the On position, the PCM cycles the air
conditioning clutch on and off when the A/C switch
closes. When the PCM senses low idle speeds or wide
open throttle through the throttle position sensor, it
de-energizes the A/C clutch relay. The relay contacts
open, preventing air conditioning clutch engagement.
On AA body vehicles, the relay is located next to
the drivers side strut tower (Fig. 13).
On AG and AJ body vehicles, the relay is located
in the power distribution center (Fig. 14).
GENERATOR FIELD—PCM OUTPUT
The PCM regulates the charging system voltage
within a range of 12.9 to 15.0 volts. Refer to Group
8A for charging system information.
Fig. 11 Vehicle Speed Sensor—Typical
Fig. 12 Relay Identification (AC Body)
14 - 118
FUEL SYSTEMS
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