TM 9-6115-730-24
0009
TROUBLESHOOTING USING GSC FAULT CODES - Continued
NOTE
The magnetic pickup unit (MPU) on this engine is located at the rear of the engine on the flywheel
housing.
SYMPTOM
24.
CID 190 FMI 02
CID 190 FMI 03
MALFUNCTION
Loss of Engine Speed Signal.
Magnetic pickup unit (engine speed sensor).
FMI 02 - Erratic, intermittent, or incorrect signal.
FMI 03 - Voltage above normal.
CORRECTIVE ACTION
STEP 1.
Turn the ENGINE CONTROL switch to OFF/RESET.
STEP 2.
Disconnect ENG-P14 from the magnetic pickup unit (MPU) (WP 0088, Figure 2,
Sheet 2, and FO-2, Sheet 2).
STEP 3.
Measure MPU resistance.
a. If resistance is not 100 to 350 ohms, replace the MPU (WP 0098).
b. If resistance is correct, set DVM to AC volts. Turn DEAD CRANK SWITCH
to CRANK. Measure 2 to 3 Vac from ground to ENG P14-1 and ENG P14-2
(MPU pigtail connector).
(1) If voltage measurement is not OK, adjust the MPU (WP 0098). Verify the
problem is resolved. If not, the MPU is damaged or it is not functioning.
Replace the magnetic pickup unit (WP 0098). Verify the problem is
resolved.
(2) If the voltage measurement is OK, the MPU is functioning OK. Replace
LSM A4 (WP 0041). Verify the problem is resolved.
STEP 4.
Reconnect ENG-P14 to the MPU ).(WP 0088, Figure 2, sheet 2, andFO-2, sheet
2). Disconnect ENG-P37 from the back of the GSC. Measure resistance
between ENG-P37-1 and ENG-P37-2. Resistance should be 100 to 350 ohms.
a. If resistance is not 100 to 350 ohms, troubleshoot wiring harness between
ENG-P37 and ENG-P14 (WP 0088). Repair as necessary (WP 0088).
Verify the problem has been resolved.
b. If the problem has not been resolved, troubleshoot wiring between EMCP
J37-1 to GSC P7-1 and EMCP J37-2 to GSC P7-2. Repair as necessary
c.
If the problem has not been resolved, check all GSC fuses (FO-4, Sheets 3
and 5).
d. If GSC fuses are ok, replace GSC (WP 0041).
STEP 5.
Verify the problem has been resolved.
0009-20
