Air Cleaner Restriction Indicator; Fuel Pedal; Fuel Pedal Adjustment; Potentiometer Replacement - PREVOST H3-41 Maintenance Manual

7.4 AIR CLEANER RESTRICTION INDICATOR

A resettable restriction indicator may be installed
on the engine air-intake duct, clearly visible from
the rear engine compartment.
monitors the vacuum level between the air
cleaner and the engine. A red marker is
displayed when the air cleaner is clogged and
must be replaced. Reset by pressing on the
indicator's extremity.
FIGURE 21: RESTRICTION INDICATOR
MAINTENANCE
Air cleaner
Change the filter element when indicated by
the restriction indicator or at the intervals
specified by the Lubrication And Servicing
Schedule in Section 24: LUBRICATION &
SERVICING.

8. FUEL PEDAL

The EFPA (Electronic Foot Pedal Assembly)
connects the accelerator
potentiometer (a device that sends an electrical
signal to the ECM, which varies in voltage,
depending on how far down the pedal is
depressed). The EFPA is installed in the space
normally occupied by a mechanical foot pedal.
It has maximum and minimum stops that are
built into the unit during manufacturing.

8.1 FUEL PEDAL ADJUSTMENT

The EFPA contains a throttle position sensor
that varies the electrical signal sent to the ECM.
The sensor must be adjusted whenever an
The indicator
01052
pedal to a
PA1621 Maintenance Manual All Series | Section Revised September 2017
SECTION 03 : FUEL SYSTEM
EFPA is serviced. In addition, the sensor should
be adjusted any time codes 21 and 22 are
flashed.
With the ignition "ON" and the proper diagnostic
tool (DDR) (for information regarding the DDR,
see "01 ENGINE" in this manual), check the
throttle counts at idle and full throttle positions.
Proper pedal output should be 20/30 counts at
idle and 200/235 at full throttle. If adjustment is
necessary, remove the potentiometer retaining
screws and rotate the potentiometer clockwise
to increase counts or counterclockwise to
decrease. When correct output is confirmed,
tighten retaining screws.

8.2 POTENTIOMETER REPLACEMENT

1. Disconnect cable harness connector.
2. Loosen the two
potentiometer. Retain for re-assembly.
3. Discard potentiometer (Figure 22).
CAUTION
Note the routing and clamping locations of the
cable before disassembly. Proper cable
routing and fastening is critical to the
operation of this system.
4. Position new
potentiometer onto the potentiometer shaft,
matching cutouts in shaft to drive tangs of
potentiometer. Apply
potentiometer has bottomed out in housing.
Reinstall screws (Figure 22) and tighten just
enough to secure potentiometer lightly.
TORQUE: 10-20 lb-in (1.13-2.26 Nm)
5. Reconnect electronic foot pedal assembly's
cable harness to the ECM connector. If
potentiometer calibration is necessary (see
"FUEL PEDAL ADJUSTMENT"
section).
CAUTION
Make sure the cable harness is routed
correctly, and securely installed so that it does
not become pinched, stretched, or otherwise
damaged during vehicle operation.
screws and remove
potentiometer. Press
hand pressure until
in this
17