TM 5-3805-290-23-1
ELECTRICAL SYSTEM TESTS, INSPECTIONS, AND ADJUSTMENTS - CONTINUED
0013 00
ENGINE SPEED/TIMING SENSOR CIRCUIT TEST - CONTINUED
3.
Measure sensor resistance through wiring harness.
427-B0712
a.
Turn engine start switch to OFF position (TM 5-3805-290-10).
b.
Disconnect P1 ECM connector (WP 0053 00).
c.
Use multimeter to measure resistance of sensor from 41 terminal to 49 terminal.
d.
Wiggle cables associated with engine speed/timing sensor while resistance is measured to check for an intermittent
open or short circuit. Resistance should be 75 to 230 Ohms
e.
Expected Results. Readings agree with values listed in step d.
(1)
If results are OK, neither short circuit nor open circuit is indicated. Proceed to step 5.
(2)
If results are NOT OK, resistance is not within acceptable range when circuit resistance is measured
through engine harness. Reconnect and proceed to step 4.
4.
Measure resistance of sensor.
a.
Turn engine start switch to OFF position (TM 5-3805-290-10).
b.
Check harness and wiring for abrasions and pinch points from sensor back to ECM.
c.
Disconnect P401 engine speed/timing sensor connector (WP 0067 00).
d.
Thoroughly inspect J401/P401 engine speed/timing sensor connector. Refer to Electrical Connectors Inspection
(WP 0022 00). Resistance should be 75 to 230 Ohms.
e.
Expected Results. Readings agree with values listed in step d.
(1)
If results are OK, sensor resistance is within tolerance. There is fault in cable between P1 ECM connector
and P401 connector. Replace wiring harness in question (WP 0169 00 thru WP 0175 00). Verify repair has
eliminated faults.
(2)
If results are NOT OK, sensor resistance is out of range. Perform this procedure to check and install new
sensor:
(a) Before installing new sensor, measure resistance of new sensor.
(b) If new sensor resistance is in correct range, install new sensor in engine (WP 0067 00).
(c) Ensure O-ring is installed and free of damage.
(d) Seat sensor and tighten setscrew. If sensor will not seat, replace sensor (WP 0067 00), as required.
(e) Ensure sensor is properly oriented and harness is secured in proper location.
(f) Verify repair eliminates problem.
0013 00-42
