TM 5-3805-293-23-1
0011
Table 1. Engine Troubleshooting Procedures for the 120M Motor Grader - Continued.
MALFUNCTION
TEST OR INSPECTION
CORRECTIVE ACTION
C AU T I O N
18. Low Engine Oil Pressure
Do not operate the engine with low oil pressure. Engine damage will
result. If measured oil pressure is low, discontinue engine operation
until the problem is corrected.
1. Connect MSD (WP 0006). Select
Active Event or Diagnostic Codes
Engine ECM C6.6 120M and
Found - Troubleshoot any active
check for any active event or
codes before continuing with this
diagnostic fault codes.
procedure (WP 0010).
2. Check the oil level in the engine
Oil Low - Add oil as needed (TM 5-
(TM 5-3805-293-10).
3805-293-10).
3. Check for leaks in the engine oil
Engine Oil Cooler or Engine Oil
cooler assembly. Refer to Engine
Cooler Core Cracked or Dented -
Oil Cooler Inspection (WP 0036).
Replace engine oil cooler (WP 0089).
4. Check the actual engine oil pres-
Engine Oil Pressure Less Than 37
sure with a calibrated test gauge,
psi - Replace engine oil pump (WP
refer to "Engine Oil Pressure -
0092), then proceed to step 5.
Test" (WP 0033). Note engine oil
Engine Oil Pressure Greater Than
pressure on calibrated test gauge.
85 psi - Replace engine oil pump (WP
0092).
Engine Oil Pressure is Less Than
45 psi (310 kPa) with Throttle Fully
Depressed - Replace engine oil
pump (WP 0092), then proceed to
step 5.
5. Perform Engine Oil Pressure Test
Oil Pressure Remains Less Than 37
(WP 0033).
psi - Replace engine (WP 0069).
Engine Oil Pressure Remains Less
Than 45 psi with Throttle Fully
Depressed - Replace engine (WP
0069).
Active Event or Diagnostic Codes
19. Low Power/Poor or No
1. Connect MSD (WP 0006). Select
Found - Troubleshoot any active
Response to Throttle
Engine ECM C6.6 120M and
codes before continuing with this
check for any active event or
procedure (WP 0010).
diagnostic fault codes.
2. Perform Fuel Quality Test (WP
Fuel System is Contaminated -
Drain fuel (WP 0229), replace primary
0035).
fuel filter (WP 0174), replace
secondary fuel filter (WP 0073), and
fill with correct fuel (TM 5-3805-293-
10) for machine operation.
3. 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).
0011-18
