850082T 5 Mercury CYLINDER BLOCK

Table 1
J1939 Code and Description CDL Code and Description Comments
5966-5
Aftertreatment #1 DEF Control Module Power Supply : Current Below Normal 3965-5
Aftertreatment #1 Diesel Exhaust Fluid Control Module Power Supply #1 : Current Below Normal An open circuit has been detected on the keyswitch circuit between the Selective Catalyst Reduction (SCR) System and the Diesel Exhaust Fluid Control Unit (DCU).
5966-6
Aftertreatment #1 DEF Control Module Power Supply : Current Above Normal 3965-6
Aftertreatment #1 Diesel Exhaust Fluid Control Module Power Supply #1 : Current Above Normal A short circuit has been detected on the keyswitch circuit between the SCR System and the DCU.
6309-5
Aftertreatment #1 DEF Control Module #1 Power Supply #2 : Current Below Normal 3966-5
Aftertreatment #1 Diesel Exhaust Fluid Control Module Power Supply #2 : Current Below Normal An open circuit has been detected on the keyswitch circuit between the SCR System and the DCU.
6309-6
Aftertreatment #1 DEF Control Module #1 Power Supply #2 : Current Above Normal 3966-6
Aftertreatment #1 Diesel Exhaust Fluid Control Module Power Supply #2 : Current Above Normal A short circuit has been detected on the keyswitch circuit between the SCR and the DCU.
7522-5
Aftertreatment #1 DEF Control Module #2 Power Supply #1 : Current Below Normal 4799-5
Aftertreatment #1 Diesel Exhaust Fluid Controller #2 Power Supply #1 : Current Below Normal An open circuit has been detected on the keyswitch circuit between the SCR System and the DCU.
7522-6
Aftertreatment #1 DEF Control Module #2 Power Supply #1 : Current Above Normal 4799-6
Aftertreatment #1 Diesel Exhaust Fluid Controller #2 Power Supply #1 : Current Above Normal A short circuit has been detected on the keyswitch circuit between the SCR System and the DCU.
7523-5
Aftertreatment #1 DEF Control Module #2 Power Supply #2 : Current Below Normal 4800-5
Aftertreatment #1 Diesel Exhaust Fluid Controller #2 Power Supply #2 : Current Above Normal An open circuit has been detected on the keyswitch circuit between the SCR System and the DCU.
7523-6
Aftertreatment #1 DEF Control Module #2 Power Supply #2 : Current Above Normal 4800-6
Aftertreatment #1 Diesel Exhaust Fluid Controller #2 Power Supply #2 : Current Above Normal A short circuit has been detected on the keyswitch circuit between the SCR System and the DCU.
Illustration 1 g06054803
The DCUs are on the rear of the Pump Electronic Tank Unit (PETU).
(1) DCU 2
(2) DCU 1
(3) ECM J2
(4) ECM J1
Table 2
Troubleshooting Test Steps Values Results
1. Check for Codes
A. Connect Cat® Electronic Technician (ET) to the service tool connector.
B. Determine if a code is active or logged.
Codes
Result: A -5 code is active or logged.
Proceed to Test Step 2.
Result: A -6 code is active or logged.
Proceed to Test Step 3.
2. Check the Diesel Exhaust Fluid Control Unit (DCU) Wiring for an Open Circuit
A. Turn the keyswitch to the OFF position for 2 minutes. The keyswitch must be off for 2 minutes to