Table 2. Engine Troubleshooting with Codes for the 120M Motor Grader - Continued.
CDI FMI CODE
N OT E
2770-03 Throttle Hold
Resume/Decel Switch Volt-
The throttle lock feature is activated through the use of the throttle lock
age Above Normal - Contin-
switch and the "throttle lock set/accel switch" in order to maintain a
desired engine speed. The throttle lock switch is a three-position rocker
switch that is used to select the mode of operation. The throttle lock
feature has the following three modes of operation: Automatic mode,
Manual mode, and OFF.
Depress the throttle lock switch in the forward direction to the AUTO
position in order to select the automatic mode. Use the throttle pedal to
achieve the desired engine speed and then depress the "throttle lock
set/accel switch" in the forward direction (SET/ACCEL) in order to set
the desired engine speed.
Deceleration: Moving the "throttlelock resume/decel switch" (RESUME/
DECEL) on the joystick will decrease the desired engine speed.
Momentarily bumping the "throttle lock resume/decel switch" will
decrease the desired engine speed by 100 rpm. Holding the "throttle
lock resume/decel switch" for more than 250 milliseconds will decrease
the desired engine speed at a rate of 700 rpm per second.
Test Step 1. Verify Diagnostic Code
and Parameter Status.
N OT E
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.
Engine ECM C6.6 120M.
2. Start and run the engine.
N OT E
Wait at least 30 seconds in order for diagnostic codes to become active.
3. Verify diagnostic code 2770-03 is
Diagnostic Code 2770-03 Active -
Proceed to Test Step 2.
Test Step 2. Test Throttle Lock
Resume/Decel Switch Circuit.
1. Turn the ignition switch and bat-
tery disconnect switch to the OFF