ELECTRICAL SYSTEM TESTS, INSPECTIONS, AND ADJUSTMENTS - CONTINUED
CHARGING SYSTEM TEST - CONTINUED
Measure the voltage across the battery. Put the red lead on the positive battery terminal, and put the black lead on the
negative battery terminal. Step 4 should be completed as quickly as possible after step 3.
Expected Results: Voltage is within 2V of voltage recorded in step 3.
If the voltage in step 3 is not more than 2V higher than the voltage in step 4 this test is complete and the related
wiring is correct at this time. Replace the alternator (WP 0047 00).
If the voltage in step 3 is more than 2V higher then the voltage in step 4, there is high circuit resistance: corrosion,
loose connections, and damaged wiring. Continue to step 5.
Check the voltage between the machine frame and alternator B+ terminal. Record the voltage.
Check the voltage between the machine frame and the positive battery post. Step 6 should be completed as quickly as
possible after step 5.
Expected Results: The voltage difference between step 5 and step 6 does not exceed 1V.
If voltage difference does not exceed the tolerance, charging circuit is good. Go to step 7.
If voltage difference exceeds the tolerance, there is high resistance in the charging circuit: loose cables, corroded
cables, damaged cables, and faulty circuit breaker. Correct the problem and retest the system.
Check the voltage between the negative battery post and the alternator case ground.
Expected Results: Voltage does not exceed 1V.
If voltage difference does not exceed the tolerance, ground circuit is good. There is an internal problem with the
alternator. Replace alternator (WP 0047 00).
If voltage difference exceeds the tolerance, there is high resistance in the ground circuit: loose cables, corroded
cables, loose alternator mounting, and poor engine ground. Correct problem and test system.
DIGITAL THROTTLE POSITION SENSOR CIRCUIT TEST
N OT E
· Use this procedure if any of these diagnostic codes are active:
a. 91-08 Throttle Position signal abnormal.
b. 774-08 Sec Throttle Position Sensor Signal Abnormal.
c. 41-03 8 Volt dc Supply Short to +Batt.
d. 41-04 8 Volt dc Supply Short to Ground.
· Pedal-mounted throttle position sensor provides throttle position signal to ECM. Pedal-mounted throttle posi-
tion sensor is attached directly to throttle assembly. Foot or hand-operated versions of throttle assembly are
· Pedal-mounted throttle position sensor will produce duty cycle of 10 to 22 percent at low idle and 75 to 90 per-
cent when accelerator pedal is fully pressed.
· Pedal-mounted throttle position sensor will produce minimum duty cycle when pedal is released. Pedal-
mounted throttle position sensor will produce maximum duty cycle when pedal is fully pressed.
· Pedal-mounted throttle position sensor sends pulse width modulated (PWM) signal. Signal varies with throttle
position. Signal is expressed as percentage.