P2049

P2049-(DIESEL EXHAUST FLUID) REDUCTANT INJECTOR CIRCUIT HIGH




For a complete wiring diagram, refer to the Wiring Information.
Theory of Operation

The Diesel Exhaust Fluid (DEF) Injector is mounted to the decomposition tube at the inlet of the Selective Catalytic Reduction (SCR) Catalyst. The DEF Dosing Control Unit sends a Pulse Width Modulated (PWM) signal to DEF Injector to vary the amount of fluid sprayed into the exhaust stream. The DEF Dosing Control Unit will illuminate the MIL lamp via the Powertrain Control Module (PCM) immediately after this diagnostic runs and fails and diesel exhaust fluid injection into the after treatment system is disabled. The DEF Dosing Control Unit will turn off the MIL lamp via the PCM immediately after the diagnostic runs and passes for three consecutive key cycles.

- When Monitored:
With the ignition on and the DEF Injector is commanded on.

- Set Condition:
The DEF Dosing Control Unit that the DEF Injector control circuit voltage is above a calibrated value.





Always perform the Pre-Diagnostic Troubleshooting procedure before proceeding. Pre-Diagnostic Troubleshooting Procedure.

1. ACTIVE DTC
1. Turn the ignition on, engine not running.
2. With the scan tool, View DTCs.

Is the DTC active?

Yes

- Go To 3

No

- Perform the INTERMITTENT CONDITION - 6.7L. Intermittent Condition Test

2. DEF INJECTOR
1. With the scan tool, Erase DTCs.
2. Turn ignition off.
3. Disconnect the DEF Injector harness connector.
4. Turn the ignition on.
5. With the scan tool, navigate to Systems Tests actuate of the Diesel Exhaust Fluid Doser Pump Override Test.
6. With the scan tool, View DTCs.

Does DTC P2048 become active and P2049 stored with the DEF Injector harness connector disconnected?

Yes

- Replace the DEF Injector. Diesel Exhaust Fluid Injector - Removal.
- Perform the POWERTRAIN VERIFICATION TEST - 6.7L. Powertrain Verification Test.

No

- Go To 3

3. CHECK FOR THE (K428) DEF INJECTOR SIGNAL CIRCUIT SHORTED TO ANOTHER CIRCUIT




1. Turn ignition off.
2. Disconnect the DEF Dosing Control Unit C1 harness connector.
3. Measure the resistance between the (K428) DEF Injector Signal circuit and all other circuits at the DEF Dosing Control Unit C1 harness connector.

Is the resistance above 10k Ohms between the (K428) DEF Injector Signal circuit and all other circuits?

Yes

- Go To 4

No

- Repair the short between the (K428) DEF Injector Signal circuit and the circuit that measured below 10k Ohms.
- Perform the POWERTRAIN VERIFICATION TEST - 6.7L. Powertrain Verification Test.

4. CHECK FOR THE (K426) DEF INJECTOR RETURN CIRCUIT SHORTED TO ANOTHER CIRCUIT




1. Measure the resistance between the (K426) DEF Injector Return circuit and all other circuits at the DEF Dosing Control Unit C1 harness connector.

Is the resistance above 10k Ohms between the (K426) DEF Injector Return circuit and all other circuits?

Yes

- Replace the DEF Dosing Control Unit. Diesel Exhaust Fluid Dosing Control Unit - Removal.
- Perform the POWERTRAIN VERIFICATION TEST - 6.7L. Powertrain Verification Test.

No

- Repair the short between the (K428) DEF Injector Return circuit and the circuit that measured below 10k Ohms.
- Perform the POWERTRAIN VERIFICATION TEST - 6.7L. Powertrain Verification Test.