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.
- 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 DEF LINE HEATER RELAY
- With the scan tool, Erase DTCs.
- Turn the ignition off.
- Replace the DEF Line Heater Relay with a known good relay.
- Turn the ignition on.
- With the scan tool, navigate to Actuator Tests and actuate the Line Heater Relay.
- With the scan tool, View DTCs.
Did the DTC return?
Yes
- Go To 3.
No
- Repair complete.
- Perform the POWERTRAIN VERIFICATION TEST - 6.7L. Refer to POWERTRAIN VERIFICATION TEST - 6.7L .
- CHECK THE (K475) DEF LINE HEATER RELAY SIGNAL CIRCUIT FOR A SHORT TO GROUND
- Stop actuation of the Line Heater Relay.
- Turn the ignition off.
- Remove the DEF Line Heater Relay.
- Disconnect the DEF Dosing Control Unit C2 harness connector.
- Measure the resistance between ground and the (K475) DEF Line Heater Relay Signal circuit at the Line Heater Relay, terminal 86.
Is the resistance above 10k Ohms?
Yes
- Go To 4.
No
- Repair the (K475) DEF Line Heater Relay Signal circuit for a short to ground.
- Perform the POWERTRAIN VERIFICATION TEST - 6.7L. Refer to POWERTRAIN VERIFICATION TEST - 6.7L .
- CHECK THE (K429) DEF LINE HEATER RELAY CONTROL CIRCUIT FOR A SHORT TO GROUND
- Measure the resistance between ground and the (K429) DEF Line Heater Relay Control circuit between the Line Heater Relay, terminal 85.
Is the resistance above 10k Ohms?
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 (K429) DEF Line Heater Relay Control circuit for a short to ground.
- Perform the POWERTRAIN VERIFICATION TEST - 6.7L. Refer to POWERTRAIN VERIFICATION TEST - 6.7L .
- Measure the resistance between ground and the (K429) DEF Line Heater Relay Control circuit between the Line Heater Relay, terminal 85.