TM 5-3805-293-23-1
0011
Table 1. Engine Troubleshooting Procedures for the 120M Motor Grader - Continued.
MALFUNCTION
TEST OR INSPECTION
CORRECTIVE ACTION
N OT E
4. Can Not Reach Top
Engine RPM
If this fault occurs only under load, refer to Troubleshooting, "Low
Power/Poor or No Response to Throttle".
1. Connect the MSD (WP 0006).
Active Event or Diagnostic Fault
Select Engine ECM C6.6 120M
Code - Troubleshoot fault codes (WP
and check for any active event or
diagnostic fault codes.
2. Inspect air inlet system for
Air Inlet System is Blocked or Dirty
damage, blockage, and
- Clean and remove blockage from air
cleanliness (WP 0037).
inlet system components (WP 0037).
Air Inlet System Components are
Damaged - Replace damaged com-
ponents (WP 0115, WP 0078, and WP
0103).
3. Inspect exhaust system for
Exhaust System is Blocked -
damage and blockage (WP
Remove blockage (WP 0037).
0037).
Exhaust System Components are
Damaged - Replace damaged com-
ponents (WP 0077, WP 0076, WP
0063, and WP 0079).
4. Perform Fuel Quality Test (WP
Fuel System is Contaminated -
0035).
Drain fuel (WP 0229), replace primary
fuel filter (WP 0174), replace second-
ary fuel filter (WP 0073), and fill with
correct fuel (TM 5-3805-293-10) for
machine operation.
5. Perform Fuel System Inspection
Fuel Rail Lines Leaking - Replace
(WP 0035).
fuel rail lines (WP 0072).
Low Pressure Fuel Lines Leaking -
Tighten lines (WP 0173).
Low Pressure Fuel Lines
Restricted/Damaged - Replace low
pressure fuel line (WP 0173).
Primary Fuel Filter and Water Sepa-
rator Damaged or Contaminated -
Replace primary fuel filter and water
separator (WP 0174).
Secondary Fuel Filter Damaged or
Contaminated - Replace secondary
fuel filter (WP 0073).
Lines Loose or Not Secured -
6. Verify that the low pressure fuel
Tighten lines and secure as needed
lines are tight and secured
(WP 0173).
properly (WP 0173).
Change 1
