TM 10-3930-675-20-1
0027 00-2
TRANSMISSION SPEED SENSORS TROUBLESHOOTING - CONTINUED
0027 00
Table 1. Error Code 649 - Engine Speed Sensor Failure, Open Circuit or Short Circuit
to Battery Troubleshooting Procedures - Continued.
MALFUNCTION
TEST OR INSPECTION
CORRECTIVE ACTION
Error Code 649 - Engine Speed Sensor Failure,
Open Circuit or Short Circuit to Battery -
Continued
3. Move cab to transport position
and
remove
transmission
access covers (WP 0135 00).
4. Check transmission electrical
harness connector 761 located
on right side of transmission at
engine speed sensor for proper
connection.
Connect loose or disconnected
connectors.
5. Check continuity between
connector 761 pin 1 and
connector X173 pin 4 and
between connector 761 pin 2
and connector X173 pin 5.
a. If continuity is not present,
repair or replace connectors
(WP 0111 00).
b. If wiring harness must be
replaced, notify SRA.
6. Disconnect
connector
on
transmission ECU connector.
7. Check continuity between
transmission ECU connector
pin 19 and connector X173 pin
4 and between transmission
ECU connector pin 3 and
connector X173 pin 5.
a. If continuity is not present,
repair or replace connectors
(WP 0111 00).
b. If wiring harness must be
replaced, notify SRA.
8. If continuity was present in
either steps 5 or 7, disconnect
transmission speed sensor
connector 761 and perform an
internal resistance check of
engine
speed
sensor.
Resistance should be 1050 +/-
100 ohms.
If resistance is not as specified,
replace engine speed sensor (WP
0095 00).
