Diagnostic Test

WARNING: This page is about a different variant/trim than selected.

CHECK FOR AN 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. Refer to INTERMITTENT DTC .
CHECK THE (K428) DEF INJECTOR POSITIVE CIRCUIT FOR A SHORT TO ANOTHER CIRCUIT
1. Turn ignition off.
2. Disconnect the DEF Injector harness connector.
3. Disconnect the PCM C2 harness connector.
4. Measure the resistance between the (K428) DEF Injector Positive circuit and all other circuits at the PCM C2 harness connector.
  Is the resistance above 10k Ohms between the (K428) DEF Injector Positive circuit and all other circuits?
  
  Yes
  - Go To 3
  No
  - Repair the short between the (K428) DEF Injector Positive circuit and the circuit that measured below 10k Ohms.
  - Perform the POWERTRAIN VERIFICATION TEST. Refer to PCM VERIFICATION TEST .
CHECK THE (K426) DEF INJECTOR NEGATIVE CIRCUIT FOR A SHORT TO ANOTHER CIRCUIT
1. Measure the resistance between the (K426) DEF Injector Negative circuit and all other circuits at the PCM C2 harness connector.
  Is the resistance above 10k Ohms between the (K426) DEF Injector Negative circuit and all other circuits?
  
  Yes
  - Go To 4
  No
  - Repair the short between the (K428) DEF Injector Negative circuit and the circuit that measured below 10k Ohms.
  - Perform the POWERTRAIN VERIFICATION TEST. Refer to PCM VERIFICATION TEST .
CHECK THE DEF INJECTOR FOR PROPER OPERATION
1. Turn ignition off.
2. Reconnect the PCM C2 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 the Diesel Exhaust Fluid Injector Quantity Test.
  NOTE:
  This Test is broken up into three parts: 1-Air bleed/Build Pressure (about 30 seconds/then empty the container), 2-Main volume test (a little over one minute), 3-DEF purge (to remove excess fluid from the lines after the test). The entire procedure will run for 2-3 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 26 ml and 35 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. Refer to PCM VERIFICATION TEST .
  No
  - Replace the DEF Injector in accordance with the service information.
  - Perform the POWERTRAIN VERIFICATION TEST. Refer to PCM VERIFICATION TEST .