Diagnostic Test
WARNING: This page is about a different car, the 2011 RAM Cab & Chassis. However, it is still accessible from the selected car via links, so may be relevant.
- ACTIVE DTC
- Turn the ignition on, engine not running.
- With the scan tool, navigate to Systems Tests and actuate the Pressure Line Heater.
- With the scan tool, View DTCs.
Is the DTC active?
Yes
- Go To 2.
No
- Perform the INTERMITTENT CONDITION - 6.7L diagnostic procedure. Refer to INTERMITTENT CONDITION - 6.7L .
- CHECK THE RESISTANCE OF THE DEF PRESSURE LINE HEATER
- Turn the ignition off.
- Disconnect the DEF Pressure Line Heater harness connector.
- Measure the resistance across the terminals of the DEF Pressure Line Heater.
Does the resistance measure between 5.7 Ohms and 6.9 Ohms?
Yes
- Go To 3.
No
- Replace the DEF Pressure Line in accordance with the service information. Refer to LINE, Diesel Exhaust Fluid Pressure , Removal .
- Perform the POWERTRAIN VERIFICATION TEST - 6.7L. Refer to POWERTRAIN VERIFICATION TEST - 6.7L .
- CHECK THE (K478) DEF PRESSURE LINE HEATER RETURN CIRCUIT FOR A SHORT TO ANOTHER CIRCUIT
Courtesy of CHRYSLER LLC
- With the DEF Pressure Line Heater harness connector still disconnected, disconnect the DEF Dosing Control Unit C1 harness connector.
- Measure the resistance between the (K478) DEF Pressure Line Heater Return circuit and all other circuits at the DEF Dosing Control Unit C1 harness connector.
Is the resistance above 10k Ohms between the (K478) DEF Pressure Line Heater Return circuit and all other circuits?
Yes
- Replace the DEF Dosing Control Unit in accordance with the service information. Refer to UNIT, Diesel Exhaust Fluid Dosing Control , Removal .
- Perform the POWERTRAIN VERIFICATION TEST - 6.7L. Refer to POWERTRAIN VERIFICATION TEST - 6.7L .
No
- Repair the short between the (K478) DEF Pressure Line Heater Return circuit and the circuit that measured below 10k Ohms.
- Perform the POWERTRAIN VERIFICATION TEST - 6.7L. Refer to POWERTRAIN VERIFICATION TEST - 6.7L .