ELECTRICAL SYSTEM TESTS, INSPECTIONS, AND ADJUSTMENTS - CONTINUED
DIGITAL THROTTLE POSITION SENSOR CIRCUIT TEST - CONTINUED
Expected Results. Diagnostic codes are not active after disconnecting throttle sensor.
If results are OK, diagnostic codes are not active after disconnecting throttle position sensor. Reconnect
throttle sensor and proceed to step 6.
If results are NOT OK, install new throttle position sensor (WP 0039 00). Use MSD to verify diagnostic
codes are still active. Clear all logged codes.
Disconnect throttle position sensor supply terminals at
Turn engine start switch to OFF position (TM 5-
Use pin removal tool to remove P1:17 (+8V) and
P1:44 (sensor common) from ECM connector
Turn engine start switch to ON position (TM 5-
Use MSD to check for active diagnostic codes.
Expected Results. Diagnostic codes are active.
If results are OK, check for proper battery voltage. Check battery voltage for P1 between terminal 56 and
terminal 57 to terminal 68 and terminal 69. Voltage should be between 22.0 to 27.0V. If battery voltage is
present and diagnostic codes are still active, then ECM does not operate correctly.
Replace engine ECM (WP 0053 00). Verify repair eliminates problem.
If results are NOT OK, a short circuit exists in harness or connectors. Connect cables one at a time. Con-
nect terminal 44 to ECM. Verify diagnostic code reappears, then connect terminal 17 to ECM. Use MSD
to verify diagnostic code reappears. Replace wiring harness in question (WP 0169 00 thru WP 0175 00).
Verify repair has eliminated fault.
Check position of throttle position sensor.
Install breakout T with three terminals on throttle position sensor.
Measure PWM signal. Connect one probe to terminal C (throttle position sensor) and other one probe to terminal B
(sensor common) of breakout T.
Observe position while engine speed control is moved from minimum to maximum position.
Expected Results. Position should be between 10 and 22 percent in low idle position. Position should be between
75 and 90 percent in high idle position.
If results are OK, throttle position sensor is working properly. Proceed to step 8.
If results are NOT OK, throttle position sensor is faulty. Proceed to step 9.