Table 2. Engine Troubleshooting with Codes for the 120M Motor Grader - Continued.
CDI FMI CODE
1797-03 Fuel Rail Pressure
Sensor Voltage Above Nor-
harness is open, replace engine
mal - Continued
harness connector EA-C1 (WP
control wiring harness (WP 0080).
0009, Figure 3) terminal 40, and
fuel rail pressure sensor harness
less than 5.0 Ohms) - ECM faulty,
replace Engine ECM (WP 0067).
ure 25) terminal 2.
Connect the fuel rail pressure sensor
There should be good continuity.
1797-04 Fuel Rail Pressure
Sensor Voltage Below Nor-
A warning will appear on display on
instrument panel. ECM will log diag-
nostic code. Electronic service tool
will display Voltage Below Normal
next to Desired Fuel Rail Pressure
and Actual Fuel Rail Pressure on sta-
Possible Performance Effect:
Engine will be derated.
N OT E
The 5-Volt supply circuit is a common supply circuit which is bussed
internally of the Engine ECM. The supply voltage is 5.0 ± 0.16 Volts.
Output of the 5-Volt supply circuit is at Engine ECM J2-46 circuit T997-
OR, J2-47 circuit L730-OR, J2-48 circuit R997-OR, and J1-42 circuit
R997-OR. The 5-Volt supply circuits are supplied to the intake manifold
pressure sensor terminal 1, the engine oil pressure sensor terminal 1,
the fuel rail pressure sensor terminal 1, and the turbocharger air inlet
pressure sensor terminal A.
Each sensor has a return or ground circuit and is a common supply
circuit which is bussed internally of the Engine ECM. The sensor return
circuit is at Engine ECM J2-40 circuit Y940-BR, J2-39 circuit Y947-BR,
J2-38 circuit T993-BR, and J1-34 circuit R993-BR.
The fuel rail pressure sensor signal circuit is an input to the Engine
ECM at Engine ECM J2-51 circuit Y946-BU.