STARTING AR. 4Z6542 - Caterpillar

Do not connect or disconnect hose fittings to or from the quick disconnect nipples when there is pressure in the system. This will prevent damage to the seals that are in the fitting.
Specifications
(1) Electronic Main Relief Valve (EMRV) pressure for the Interactive Differential (IAD) Lock ... 3200 300 kPa (465 44 psi) (2) Interactive Differential (IAD) Lock clutch pressure ... 2900 300 kPa (420 44 psi) Introduction
This test procedure will check following pressures:
the pump pressure (EMRV) to the interaxle differential lock solenoid
the interaxle differential (IAD) lock clutch pressureThe electronic main relief valve (EMRV) is an electronic controlled relief valve. This EMRV controls the maximum system pressure to the transmission solenoids, IAD lock solenoid, and torque converter lock up solenoid valves. When the ECM sends a signal to energize a solenoid, the ECM also sends a signal to the EMRV to limit the maximum pressure at the solenoid. Not all valves will have the same pressure setting.The interaxle differential clutch pressure is the pressure applied to the IAD clutch. The IAD lock solenoid supplies pressure to the IAD lock clutch. This test requires a connection to Cat ET.Required Tools
Table 1
Required Tools
Part Number Description Qty
198-4240(1) Digital Pressure Indicator 1
Cat ET communications adapter
(1) The 1U-5481 Pressure Gauge Group is also available.Test Procedure
Illustration 1 g03786961
Location of pressure test ports
(1) Electronic Main Relief Valve pressure test port
(2) Interaxle differential (IAD) lock clutch pressure test port
Connect test group to test ports (1) and (2) shown in Illustration 1.
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ET connection on the right side of the operator seat
Connect to ET. Ensure that the area is clear of personnel and start the machine.
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Refer to Illustration 3, Illustration 4, and Illustration 4. Navigate in Cat ET to the "Diagnostic Test Screen", and click on "Override Parameters".
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Click on "Interaxle Lock Solenoid Current Override".
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When the "Change Parameter Value" screen pops up, enter "1.1", and click "OK".
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A screen will appear to verify that you want to override the value. Click "Yes".
When the screen appears with the new parameter, run the engine at high idle. Observe the pressures on gage (1) and (2). The pressures should agree with the pressures listed above in "Specifications".
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When the Interaxle differential lock pressure check is complete, repeat the steps above to return the "Current Override" to Zero.
Lower the engine speed to idle. Shut down the machine, and remove test equipment.