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Home >> Jeep >> 2021 >> Cherokee Altitude, FWD >> Repair and Diagnosis >> Engine Performance >> System >> 2.4L - DTCS P0198 To P0601 >> DTC Troubleshooting >> P050B-Cold Start Ignition Timing Performance >> Diagnostic Test
July 1: So it begins. Don't worry, this is not in the correct legal jurisdiction!

Diagnostic Test

  1. CHECK FOR AN ACTIVE DTC 
    1. Turn the ignition on.
    2. With the scan tool, read DTCs and review the DTC environmental information.

      Is the DTC active or pending?

      Yes 

      • Go To  2

      No 

      • The DTC is not active at this time. Perform the INTERMITTENT CONDITION diagnostic procedure. Refer to INTERMITTENT CONDITION .
  2. CHECK FOR OTHER DTCS 
    NOTE:

    Low battery voltage can cause excessive current draw in very hot and very cold ambient temperatures. Look closely at the temperatures at which this DTC set and make sure the Battery can pass a load test if the DTC set in extreme temperatures.

    1. Refer to the recorded DTCs.

      Are there any other fuel or ignition system DTCs active or pending?

      Yes 

      No 

      • Go To  3
  3. INSPECT FOR A DIRTY AIR FILTER 
    1. Remove and inspect the Air Filter.

      Were any problems found?

      Yes 

      No 

      • Go To  4
  4. INSPECT THE THROTTLE PLATE FOR DIRT OR DEBRIS 
    1. Turn the ignition off.
    2. Remove the air cleaner assembly.
    3. Check for any signs of a foreign material (ice, dirt, or excessive carbon build up) on the throttle plate or in the bore causing the throttle plate to stick.

      Were any problems found?

      Yes 

      • Remove the debris if possible or replace the Throttle Body. Disconnect the battery when replacing the Throttle Body. After installation is complete, use a scan tool and perform the ETC RELEARN function.
      • Perform the POWERTRAIN VERIFICATION TEST. Refer to POWERTRAIN VERIFICATION TEST .

      No 

      • Go To  5
  5. CHECK FOR CONTAMINATED FUEL 
    1. Inspect the fuel for contamination. (dirt, water, or other foreign material).

      Were any problems found?

      Yes 

      • Drain the fuel from the fuel tank into an approved gas holding tank and add clean fuel. Refer to DRAINING FUEL TANK .

      No 

      • Go To  6
  6. CHECK FOR HIGH RESISTANCE IN THE (K447) ETC MOTOR (+) CIRCUIT 
    1. Turn the ignition off.
    2. Disconnect the PCM C2 harness connector.
      CAUTION:

      Do not probe the PCM harness connectors. Probing the PCM harness connectors will damage the PCM terminals resulting in poor terminal to pin connection. Install the GPEC Diagnostic Adaptor to perform the diagnosis.

    3. Connect the (special tool #10436, Adapter, GPEC Diagnostic) in line with the PCM harness connector.
    4. Using a voltmeter, perform a voltage drop test by back probing the (K447) ETC Motor (+) circuit at the Throttle Body harness connector and by probing the GPEC Adaptor. Make sure the voltmeter leads are connected so that positive polarity is displayed on the voltmeter.
      WARNING:

      When the engine is operating, do not stand in direct line with the fan. Do not put your hands near the pulleys, belts or fan. Do not wear loose clothing. Failure to follow these instructions may result in possible serious or fatal injury.

    5. Start the engine.

      Is the voltage below 0.2 volt?

      Yes 

      • Go To  7

      No 

      • Repair the (K447) ETC Motor (+) for excessive resistance.
      • Perform the POWERTRAIN VERIFICATION TEST. Refer to POWERTRAIN VERIFICATION TEST .
  7. CHECK FOR HIGH RESISTANCE IN THE (K448) ETC MOTOR (-) CIRCUIT 
    1. Turn the ignition off.
    2. Using a voltmeter, perform a voltage drop test by back probing the (K448) ETC Motor (-) circuit at the Throttle Body harness connector and by probing the GPEC Adaptor. Make sure the voltmeter leads are connected so that positive polarity is displayed on the voltmeter.
      WARNING:

      When the engine is operating, do not stand in direct line with the fan. Do not put your hands near the pulleys, belts or fan. Do not wear loose clothing. Failure to follow these instructions may result in possible serious or fatal injury.

    3. Start the engine.

      Is the voltage below 0.2 volt?

      Yes 

      • Go To  8

      No 

      • Repair the (K448) ETC Motor (-) for excessive resistance.
      • Perform the POWERTRAIN VERIFICATION TEST. Refer to POWERTRAIN VERIFICATION TEST .
  8. CHECK THE ETC MOTOR FOR PROPER RESISTANCE 
    1. Turn the ignition off.
    2. Measure the resistance of the ETC Motor by probing the appropriate terminals of the GPEC Adaptor for the (K447) ETC Motor (+) circuit and the (K448) ETC Motor (-) circuit.

      Is the resistance between 2.5 and 25 Ohms at closed throttle?

      Yes 

      • Go To  9

      No 

  9. CHECK RELATED HARNESS CONNECTIONS 
    1. Disconnect all PCM harness connectors.
    2. Disconnect all related in-line harness connections (if equipped).
    3. Disconnect the related component harness connectors.
    4. Inspect harness connectors, component connectors, and all male and female terminals for the following conditions:
      • Proper connector installation.
      • Damaged connector locks.
      • Corrosion.
      • Other signs of water intrusion.
      • Weather seal damage (if equipped).
      • Bent terminals.
      • Overheating due to a poor connection (terminal may be discolored due to excessive current draw).
      • Terminals that have been pushed back into the connector cavity.
      • Check for spread terminals and verify proper terminal tension.

      Repair any conditions that are found.

    5. Connect all PCM harness connectors. Be certain that all harness connectors are fully seated and the connector locks are fully engaged.
    6. Connect all in-line harness connectors (if equipped). Be certain that all connectors are fully seated and the connector locks are fully engaged.
    7. Connect all related component harness connectors. Be certain that all connectors are fully seated and the connector locks are fully engaged.
    8. With the scan tool, erase DTCs.
    9. Test drive or operate the vehicle in accordance with the when monitored and set conditions.
    10. With the scan tool, read DTCs.

      Did the DTC return?

      Yes 

      No 

      • The wiring or poor connection problem has been repaired.
      • Perform the POWERTRAIN VERIFICATION TEST. Refer to POWERTRAIN VERIFICATION TEST .
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