Table 4-2. Organizational Troubleshooting - continued

55-1730-229-12

320A0-OMM-000

35C2-3-473-1

1730-12/1

Table 4-2.

Organizational Troubleshooting (continued)

MALFUNCTION

TEST OR INSPECTION

CORRECTIVE ACTION

PSIG PNEUMATIC METER INDICATES PRESSURE (PNEUMATIC POWER SWITCH OFF).

61.

Step 1.

Remove engine access cover. Check visual position indicator on side

of load control valve (5, figure 4-56).

a. If valve is fully closed, go to step 5.

b. If valve is not fully closed, continue with step 2.

Step 2.

Shut down engine and set MASTER SWITCH off.

a. If load control valve is now not fully closed, replace valve

(paragraph 4-75), and perform operational check.

b. If valve is now fully closed, continue with next step.

Step 3.

Disconnect battery and lower control panel (paragraph 4-24.a).

Disconnect main harness connector P4 from ECU. Check for open

circuit from P4-T to P4-Z (figure FO-7).

a. If circuit is open, reconnect harness connector P4 to ECU and

install control panel. If load control valve is still full

open when engine is started, replace ECU (paragraph 4-31),

and perform operational check.

b. If circuit is not open, continue with next step.

Step 4.

Test PNEUMATIC POWER switch 1S8 in OFF position (malfunction 79).

a. Replace switch if defective (paragraph 4-104.c).

b. If switch tests good, check all wires and switches between

pins T and Z of harness connector P4 for shorted condition

(figure FO-7). Replace or repair any shorted wire or switch.

c. If switch and wiring is good, replace PSIG PNEUMATIC meter

Step 5.

Test PNEUMATIC POWER switch 1S8 in OFF position (malfunction 79).

a. Replace switch if defective (paragraph 4-104.c).