Programmable Relay Control Module (PRCM) Caterpillar

PRCM CID 0478 - FMI 03

Usage:

Conditions Which Generate This Code:

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Illustration 1	g00722721
Rear view of the PRCM (1) 40-pin connector (2) Relay module

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Table 1
Load Specifications For the Internal Relays of the PRCM
Relay Module and Number	Ratings For Resistive Loads	Ratings For Inductive Loads
K1	7 milliamperes to 1 Amperes (24 DCV)	None ⁽¹⁾ ⁽²⁾ ⁽³⁾
"K2", "K3", "K4", "K5" (terminal 24), "K6" and "K7"	0.5 to 10 amperes (24 DCV)	0.5 to 10 Amperes (24 DCV) ⁽³⁾
"K5" (terminals 23 and 36)	0.5 to 10 Amperes (24 DCV) and 0.5 to 10 Amperes (24 ACV)	0.5 to 5 Amperes (24 DCV) and 0.5 to 7.5 Amperes (110 ACV)

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^( 1 )	Do NOT connect inductive loads to these terminals.
^( 2 )	The contacts of the relay that is connected to terminals 13 and 14 are gold flashed. The gold socket contact provides a source of low impedance for a low current resistive load. Loads that draw higher currents, currents that are of similar levels as terminals 23 and 36 in table 1can be applied. However, if heavier loads are applied, the gold flashing will be permanently burned. This will eliminate the gold flashing from the contacts. This does not result in damage to the relay contacts, but the contacts can no longer be used for low current loads.
^( 3 )	"K1" (terminals 13 and 14) is not fused.

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Illustration 2	g00709866
The Connections for the PRCM to the Relay Module

The PRCM provides the internal relay outputs for customer's use. All relays are located in the relay module on the rear of the PRCM. If the CAT data link fails, the relay remains in the state required by the last valid input state. The relay may also be programmed to reset to the OFF position. Refer to Systems Operation, "Setpoint Viewing and Programming".

The Possible cause of a CID 0478 FMI 03 is an open circuit of the "K2" relay coil. Clear the diagnostic code from the fault log when the troubleshooting procedure is completed.

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NOTICE

Do not apply AC voltages to any relay module terminal other than terminals 23 and 36 of K5 and terminals 13 and 14 of K1 or permanent damage to the relay module will result. All other terminals have flyback diodes connected to them that increase relay life when driving inductive loads; however, this limits their use to DC voltages.

Note: All 3K-8782 Fuses ("AGC-10") in the relay module are rated at 10 Amperes DCV.

Test Step 1. CHECK THE STATUS OF THE DIAGNOSTIC CODE.

Turn the ECS to the OFF/RESET position and then turn the ECS to the STOP position.

Press the "MODE" key until the diagnostic code viewing/clearing menu appears.

Observe the upper display. Check that the CID 0478 FMI 03 is active.
Note: The "DIAG" indicator will be flashing and the CID 0478 FMI 03 will be present on the display if the diagnostic code is active.

Expected Result:

A CID 0478 FMI 03 is displayed as an active diagnostic code or the diagnostic code is inactive.

Results:

OK - The CID 0478 FMI 03 is active. Proceed to test step 2.
NOT OK - The CID 0478 FMI 03 has not occurred. Stop.

Test Step 2. CHECK THE INTERNAL CABLE OF THE RELAY MODULE.

Note: Only open the relay module in a dry environment. If the inspection and the repair takes more than twenty minutes replace the desiccant bag. The bag is located in the housing of the PRCM. See Testing and Adjusting, "Relay Module - Replace".

Turn the ECS to the OFF/RESET position.

Disconnect the battery negative cable.

Temporarily, remove the relay module from the PRCM. See Testing and Adjusting, "Relay Module - Replace".

Check the cable that attaches the relay module to the PRCM.

Expected Result:

The cable should be firmly seated in the connector. The clamp should be in place. The cable should not be damaged.

Results:

OK - The cable is firmly seated in the connector. The clamp is in place. The cable is not damaged. Reassemble the relay module to the PRCM. Proceed to test step 3.
NOT OK - One or more of the components are damaged or the components are missing.
Repair: Replace the clamp if the clamp is missing. If the cable is damaged, replace the PRCM. See Testing and Adjusting, "Programmable Relay Control Module - Replace".
Stop.

Test Step 3. RECHECK THE STATUS OF THE DIAGNOSTIC CODE

Turn the ECS to the OFF/RESET position and then turn the ECS to the STOP position.

Reconnect the battery negative cable.

Press the "MODE" key until the diagnostic code viewing/clearing menu appears.

Observe the upper display. Check the status of the CID 0478 FMI 03. The diagnostic code is active or the diagnostic code is inactive.
Note: The "DIAG" indicator will be flashing and the CID 0478 FMI 03 will be present on the display if the diagnostic code is active.

Expected Result:

A CID 0478 FMI 03 is displayed as an active diagnostic code or the diagnostic code is inactive.

Results:

OK - The diagnostic code is inactive. The problem has been fixed by this procedure. Stop.
NOT OK - The diagnostic is still active.
Repair: Replace the relay module. See Testing and Adjusting, "Relay Module - Replace".
Stop.

Test Step 4. VERIFY THE STATUS OF THE DIAGNOSTIC CODE

Turn the ECS to the OFF/RESET position and then turn the ECS to the STOP position.

The battery negative cable remains connected.

Press the "MODE" key until the diagnostic code viewing/clearing menu appears.

Observe the upper display. Check the status of the CID 0478 FMI 03. The diagnostic code is active or the diagnostic code is inactive.
Note: The "DIAG" indicator will be flashing and the CID 0478 FMI 03 will be present on the display if the diagnostic code is active.

Expected Result:

A CID 0478 FMI 03 is displayed as an active diagnostic code or the diagnostic code is inactive.

Results:

OK - The diagnostic code is inactive. The problem has been fixed by this procedure. Stop.
NOT OK - The diagnostic is still active.
Repair: Replace the PRCM. See Testing and Adjusting, "Programmable Relay Control Module - Replace".
Stop.