EPA07/10/GHG14 DDEC VI/10 Electronics and Troubleshooting Manual (DDC-SVC-MAN-0084) | 505 SPN 4374 (ACM) (GHG14) | 505.1 SPN 4374/FMI 0 – GHG14
Description | This Code Sets When the Diesel Exhaust Fluid (DEF) Pump Speed is Higher than Normal For a Given DEF Pressure |
Monitored Parameter | DEF Pump Speed, DEF Pressure |
Monitor Sequence | None |
Execution Frequency | Continuous When Enabling Conditions Met |
Typical Duration | Continuous Until Resolved |
Dash Lamps | MIL, CEL |
Engine Reaction | Derate 25% |
Verification | SCR ADS Self-Check |
Possible causes:
- Restriction in the DEF line between the DEF tank and the DEF pump
- Restriction in the DEF line between the DEF pump and the DEF dosing unit
- Air in the DEF line between the DEF tank and the DEF pump
- Restriction in the DEF pump
- Failed DEF pump
Check as follows:
NOTICE:
Customers in colder climates where winter ambient air temperatures generally stay below -11° C (12°F) need to verify that the DEF is not frozen before troubleshooting this fault code.
- Connect DiagnosticLink® .
- Turn the ignition ON (key ON, engine OFF).
- Turn the ignition OFF.
- Using DEF test strip A0005850202, check for diesel fuel or oil contamination of the DEF fluid. Does the test strip indicate contamination?
- Yes; replace the following components and refill the system with new DEF:
- DEF tank
- DEF tank header
- DEF supply line from the DEF tank to the DEF pump
- DEF line from the DEF pump to the DEF dosing unit
- DEF return line from the DEF dosing unit to the DEF tank
- DEF pump
- DEF dosing unit
- No; Go to step 7.
- Yes; replace the following components and refill the system with new DEF:
- Disconnect the DEF supply line at the dosing unit. Fill the graduated cylinder supplied in DEF test kit (P/N: W060589001900) with water. Place the end of the DEF line into the graduated cylinder as far as possible.
NOTE: Place the graduated cylinder in a secondary container to catch over flowing DEF fluid, making sure you still have clear sight of the end of the DEF line.
- Using DiagnosticLink, perform the Selective Catalyst Reduction Airless Dosing System (SCR ADS) Self-Check routine. When the service routine is running, visually inspect the DEF line for continuous air bubbles coming from the line and DEF flow.
NOTICE:
The RS SUPPLY KIT contains all the necessary parts for steps 12-15.
- Using the DEF/Doser Kit , replace the DEF pump module filter. Go to step 13.
- Replace the DEF pump inlet screen. Go to step 14.
- Replace DEF Pressure Relief Valve (PRV). Go to step 15.
- Replace DEF dosing unit inlet screen. Go to step 16.
NOTE: If air pressure is greater than 827 kPa (120 psi), use a pressure regulator.
- Prime pump with shop air. Using a rubber tipped air gun to seal around the DEF pump inlet fitting, apply clean regulated shop air to the DEF pump inlet fitting for three to five seconds.
- Connect all DEF lines and electrical connections. Go to step 18.