TM 9-6115-730-24
0011
TROUBLESHOOTING FAILURES WITHOUT FAULT CODES - Continued
SYMPTOM
30.
Auxiliary Fuel Pump Does Not Operate.
MALFUNCTION
Auxiliary Fuel Pump Solenoid Valve.
CORRECTIVE ACTION
STEP 1.
Set Battery Disconnect Switch to ON. Set DEAD CRANK SWITCH to NORMAL.
On EMCP set ENGINE CONTROL switch to COOL DOWN/STOP.
STEP 2.
Check for 24 Vdc across auxiliary fuel pump valve (AFPV) pins 1 and 2 with AUX
FUEL switch ON. Listen for a auxiliary fuel pump and AFPV operation.
a.
If 24 Vdc is present, proceed to STEP 3.
b.
If 24 Vdc is not present, proceed to STEP 7.
STEP 3.
Set Battery Disconnect Switch to OFF/RESET. Set DEAD CRANK SWITCH to
OFF. On EMCP set ENGINE CONTROL switch to OFF/RESET.
STEP 4.
On EMCP, set AUX FUEL switch to OFF (down).
STEP 5.
Open left front doors, left rear doors, and right rear doors.
STEP 6.
Verify continuity between auxiliary fuel pump valve (AFPV) pin 2 and TB5-21
STEP 7.
Measure resistance between AFPV-1 and TB5-21. If resistance not between 40
and 80 ohms, replace AFPV (WP 0059).
STEP 8.
Verify the problem has been resolved.
MALFUNCTION
Fuel Level Switch Assembly.
CORRECTIVE ACTION
STEP 1.
On EMCP set ENGINE CONTROL switch to OFF/RESET. Set Battery
Disconnect Switch to OFF. Set DEAD CRANK SWITCH to OFF.
STEP 2.
Measure resistance between fuel level switch assembly FL2B at J8-2 and relay
AFPR-8. If not less than 2 ohms, repair or replace wire harness (WP 0088).
STEP 3.
Measure resistance between fuel level switch assembly FL2B at J8-1 and AUX
FUEL pump switch (AFPS) pin 1 (FO-1, sheet 3 and FO-4, sheet 5). If not less
than 2 ohms, repair or replace wire harness (WP 0088).
STEP 4.
Check for continuity between J8-3 and AFPV pin 14.
a.
If continuity exists, proceed to STEP 5.
b.
If continuity does not exist, troubleshoot wiring (WP 0088).
STEP 5.
Unplug connector P8 from fuel level switch assembly FL2 (WP 0056).
STEP 6.
If fuel tank level indicator on EMCP shows between 3/4 and FULL, measure
continuity between J8-1 and J8-2. If not open circuit, replace fuel level switch
assembly (WP 0056).
0011-40
