TM 5-3805-293-23-1
0011
Table 2. Engine Troubleshooting with Codes for the 120M Motor Grader - Continued.
CDI FMI CODE
ERROR/EVENT
CORRECTIVE ACTION
1797-04 Fuel Rail Pressure
Test Step 1. Test Signal Circuit.
Sensor Voltage Below Nor-
N OT E
mal - Continued
Always inspect the harness connectorsthat are involved in the circuit.
Poor connections can often be the cause of a problem in an electrical
circuit. Verify that all connections in the circuit are clean and secure,
and that all connections are in good condition. If a problem with a
connection is found, correct the problem and verify that this diagnostic
code is active before performing this procedure.
Perform open or short circuit test ateach harness connection to identify
correct harness to replace.
Perform this test only if condition is active.
1. Connect MSD (WP 0006). Select
Engine ECM C6.6 120M.
2. Start and run the engine and
Diagnostic Code 1797-04 Active -
verify diagnostic code 1797-04 is
Proceed to step 2.
active.
3. Turn ignition switch to the OFF
position.
4. Disconnect the fuel rail pressure
sensor harness connector EA-C6
(WP 0009, Figure 25).
5. Start and run the engine.
N OT E
Wait at least 30 seconds in order for diagnostic codes to become active.
1797-04 Remains Active - Proceed
6. Using MSD (WP 0006), select
to step 7.
Engine ECM C6.6 120M, and
check if diagnostic code 1797-03
1797-03 Becomes Active - Fuel rail
is active.
pressure sensor is faulty, replace fuel
rail pressure sensor (WP 0111).
7. Using a digital multimeter, check
Voltage OK (4.84 - 5.16 Volts) - 5-
5-Volt supply circuit for voltage
Volt supply circuit R997-OR and
between fuel rail pressure sensor
Engine ECM test OK, proceed to
harness connector EA-C6 (WP
step 8.
0009, Figure 25) terminal 1 and
Voltage NOT OK - Proceed to Test
ground.
Step 2.
Voltage should be within 4.84 - 5.16
Volts.
8. Turn the ignition switch and bat-
tery disconnect switch to the OFF
position.
9. Disconnect harness connector
EA-C1 (WP 0009, Figure 3) from
Engine ECM J2.
Change 1
0011-170
