TM 5-3805-291-23-1
ELECTRICAL SYSTEM TESTS, INSPECTIONS, AND ADJUSTMENTS - CONTINUED
0013 00
ENGINE SPEED/TIMING SENSOR CIRCUIT TEST - CONTINUED
4.
Measure sensor resistance through engine harness.
a.
Place battery disconnect switch in OFF position (TM 5-3805-291-10).
b.
Disconnect J2/P2 ECM connector.
c.
If you are troubleshooting a problem with crankshaft (primary) speed/timing sensor, perform this procedure:
(1)
Measure resistance from P2-35 (Primary engine speed/timing +) to P2-25 (Primary engine speed/timing -).
(2)
Check for an intermittent open or short circuit by moving harness while you take resistance measurement.
Pull or shake wires that are directly behind sensor. Resistance should be 110 to 200 Ohms.
d.
If you are troubleshooting a problem with camshaft (secondary) speed/timing sensor, perform this procedure:
(1)
Measure resistance from P2-46 (secondary engine speed/timing +) to P2-47 (secondary engine speed/tim-
ing -).
(2)
Check for an intermittent open or short circuit by moving harness while you take resistance measurement.
Pull or shake wires that are directly behind sensor. Resistance should be 1,000 to 1,200 Ohms.
Expected Results. Resistance measurements are within specifications.
e.
(1)
Replace engine ECM (WP 0057 00).
(2)
If results are not OK, at least one resistance measurement is not within specifications. Proceed to step 5.
5.
Measure sensor resistance.
a.
Disconnect engine harness from suspect sensor.
b.
For crankshaft (primary) speed/timing sensor, measure resistance between terminal 2 (Primary engine speed/tim-
ing +) and terminal 1 (Primary engine speed/timing -).
c.
Resistance should be 110 to 200 Ohms.
d.
For camshaft (secondary) speed/timing sensor, measure resistance between terminal 2 (secondary engine speed/
timing +) and terminal 1 (secondary engine speed/timing -).
e.
Resistance should be 1,000 to 1,200 Ohms.
Expected Results. Resistance measurement for suspect sensor is within specification.
f.
(1)
If results are OK, there is a problem with wiring or there may be a problem with a connector. Replace wir-
ing harness in question (WP 0195 00 thru WP 0201 00). Ensure seals are properly in place and connectors
are securely connected. Verify problem is resolved.
(2)
If results are not OK, there is a problem with sensor. Replace sensor assembly (WP 0076 00 and WP 0078
00).
0013 00-40
