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
N OT E
1785-03 Intake Manifold
Pressure Sensor Voltage
Wait at least 30 seconds in order for diagnostic codes to become active.
Above Normal - Continued
9. Using the MSD (WP 0006), select
1785-03 Remains Active - Proceed
Engine ECM C6.6 120M, and
to Test Step 2.
check if diagnostic code 1785-04
1785-04 Becomes Active - Engine
is active.
ECM and return circuit test OK, intake
manifold pressure sensor is faulty.
Replace intake manifold pressure
sensor (WP 0107).
10. Turn the ignition switch and bat-
tery disconnect switch to the OFF
position.
11. Remove jumper wire from EA-C7
(WP 0009, Figure 24) terminal 3
and ground.
12. Disconnect engine ECM harness
connector EA-C1 (WP 0009, Fig-
ure 3) from Engine ECM J2.
13. Using a digital multimeter, test
Continuity - Engine control wiring
intake for continuity between
harness is shorted, replace engine
engine ECM harness connector
control wiring harness (WP 0080).
EA-C1 (WP 0009, Figure 3) termi-
No Continuity - Proceed to step 14.
nal 55, and all other terminals.
There should be no continuity.
14. Using a digital multimeter, test for
No Continuity - Engine control wiring
continuity between engine ECM
harness is open, replace engine
harness connector EA-C1 (WP
control wiring harness (WP 0080).
0009, Figure 3) terminal 55, and
Continuity - (Resistance should be
intake manifold pressure sensor
less than 5.0 Ohms) - ECM faulty,
harness connector EA-C7 (WP
replace Engine ECM (WP 0067).
0009, Figure 24) terminal 3.
Connect the EA-C7 (WP 0009, Figure
There should be good continuity.
24) harness connector to intake mani-
fold pressure sensor.
Test Step 2. Test Return Circuit.
1. Turn the ignition switch and
battery disconnect switch to the
OFF position.
2. Remove jumper wire from EA-C7
(WP 0009, Figure 24) terminal 2
and terminal 3.
3. Disconnect engine ECM harness
connector EA-C1 (WP 0009, Fig-
ure 3).
0011-160
