P202E
P202E-(DIESEL EXHAUST FLUID) REDUCTANT INJECTOR PERFORMANCE
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) after this diagnostic runs and fails in two consecutive trips and diesel exhaust fluid injection into the aftertreatment 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:
This monitor runs when the DEF Injector is being commanded on.
- Set Condition:
The DEF Dosing Control Unit detects mechanical failure of the DEF Injector.
Always perform the Pre-Diagnostic Troubleshooting procedure before proceeding. Pre-Diagnostic Troubleshooting Procedure.
1. ACTIVE DTC
1. Turn the ignition on for one minute, engine not running.
2. With the scan tool, navigate to Systems Tests and actuate the Diesel Exhaust Fluid Doser Pump Override Test.
3. With the scan tool, View DTCs.
Is the DTC active?
Yes
- Go To 2
No
- Perform the INTERMITTENT CONDITION - 6.7L diagnostic procedure. . Intermittent Condition Test
2. CHECK FOR THE (K428) DEF INJECTOR SIGNAL CIRCUIT SHORTED TO ANOTHER CIRCUIT
1. Turn ignition off.
2. Disconnect the DEF Injector harness connector.
3. Disconnect the DEF Dosing Control Unit C1 harness connector.
4. 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 3
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.
3. 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 UnitC1 harness connector.
Is the resistance above 10k Ohms between the (K426) DEF Injector Return circuit and all other circuits?
Yes
- Go To 4
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.
4. DEF INJECTOR
1. Turn ignition off.
2. Reconnect the DEF Dosing Control Unit C1 harness connector.
3. Remove the DEF Injector from the decomposition tube.
4. Reconnect the DEF Injector harness connector.
5. Place the DEF Injector in a container to capture the fluid sprayed.
6. Turn the ignition on.
7. With the scan tool, navigate to Systems Tests and actuate the Diesel Exhaust Fluid Doser Pump Override Test.
NOTE: This Test will run for six minutes before timing out. The amount of flow may fluctuate through out the test, therefore the test must be allowed to run completely in order for the results to be accurate. The fluid should spray out as a mist. There should be no dripping from the holes in the DEF Injector at any time during the duration of the test procedure.
8. Measure the amount of fluid sprayed after the test times out.
Does the fluid sprayed measure between 85 ml and 115 ml?
Yes
- The DEF Injector is functioning properly. Remove the DEF Pressure line from the DEF Injector and DEF Supply Pump Assembly and check the fittings for a partial restriction which could cause an intermittent low flow condition.
- Perform the POWERTRAIN VERIFICATION TEST - 6.7L. Powertrain Verification Test.
No
- Replace the DEF Injector. Diesel Exhaust Fluid Injector - Removal.
- Perform the POWERTRAIN VERIFICATION TEST - 6.7L. Powertrain Verification Test.