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Test Procedure

  1. KP1 CHECK FOR DIAGNOSTIC TROUBLE CODES (DTCS) 

    Is DTC P1229 present? 

    Yes No
    For DTC P1229, GO to  KP2. For a boost gauge indicates higher than normal boost, GO to  KP8.
  2. KP2 DTC P1229: CHECK THE VOLTAGE TO THE CAC PUMP RELAY COIL 
    • Ignition OFF.
    • CAC Relay connector disconnected.
    • Ignition ON, engine OFF.
    • Measure the voltage between:
      (+) CAC Relay Connector, Harness Side (-)
      VPWR - Pin 1 Ground

    Is the voltage greater than 10 V? 

    Yes No
    GO to  KP3. REPAIR the open circuit. Clear the PCM DTCs.
    REPEAT the self-test.
  3. KP3 CHECK THE CAC PUMP RELAY 
    • Ignition OFF.
    • Remove the relay from the power distribution box.
    • Measure the resistance between:
      (+) CAC Relay Connector, Component Side (-) CAC Relay Connector, Component Side
      CAC - Pin 2 VPWR - Pin 1

    Is the resistance between 65 - 100 ohms? 

    Yes No
    GO to  KP4. INSTALL a new CAC relay. Clear the PCM DTCs. REPEAT the self-test.
  4. KP4 CHECK THE CAC PUMP RELAY 
    • Carry out the CAC pump relay component test. Refer to the appropriate ELECTRONIC CONTROLS - COMPONENT TESTING article .

    Does the CAC pump relay pass the component test? 

    Yes No
    GO to  KP5. INSTALL a new CAC relay. Clear the PCM DTCs. REPEAT the self-test.
  5. KP5 CHECK FOR AN OPEN CIRCUIT BETWEEN THE PCM AND THE CAC RELAY 
    • Ignition OFF.
    • PCM connector disconnected.
    • Measure the resistance between:
      (+) PCM Connector, Harness Side (-) CAC Relay Connector, Harness Side
      CAC - Pin B51 CAC - Pin 2

    Is the resistance less than 5 ohms? 

    Yes No
    GO to  KP6. REPAIR the open circuit. Clear the PCM DTCs.
    REPEAT the self-test.
  6. KP6 CHECK FOR A SHORT TO VOLTAGE BETWEEN THE PCM AND THE CAC RELAY 
    • Ignition ON, engine OFF.
    • Measure the voltage between:
      (+) PCM Connector, Harness Side (-) Vehicle Battery
      CAC - Pin B51 Negative terminal

    Is the voltage less than 0.5 V? 

    Yes No
    GO to  KP7. REPAIR the short circuit to PWR. Clear the PCM DTCs. REPEAT the self-test.
  7. KP7 CHECK BETWEEN THE PCM AND THE CAC RELAY FOR A SHORT TO GROUND 
    • Ignition OFF.
    • Measure the resistance between:
      (+) PCM Connector, Harness Side (-) Vehicle Battery
      CAC - Pin B51 Negative terminal

    Is the resistance greater than 10K ohms? 

    Yes No
    GO to  KP8. REPAIR the short circuit. Clear the PCM DTCs.
    REPEAT the self-test.
  8. KP8 CHECK THE CAC FOR MECHANICAL OPERATION 
    NOTE: Remove the fan control relays to disable the cooling fans so the pump can be heard. Disregard the cooling fan DTCs that will set as a result of this step.
    • CAC Relay connector connected.
    • PCM connector connected.
    • Carry out the PCM KOEO self-test.
    • Observe the CAC pump.

    Does the CAC pump cycle ON and OFF? 

    Yes No
    CHECK for low fluid level in the CAC system. CHECK for cracked or incorrectly routed CAC lines or airflow blockage at the CAC radiator. REPAIR the system as necessary. If the symptom still exists, RETURN to NO DIAGNOSTIC TROUBLE CODES (DTCS) PRESENT SYMPTOM CHART INDEX , to diagnose boost gauge indicates higher than normal boost. GO to  KP9.
  9. KP9 CHECK THE VOLTAGE AND GROUND CIRCUITS AT THE CAC PUMP 
    • Charge Air Cooler (CAC) Pump connector disconnected.
    • Measure the voltage between:
      (+) Charge Air Cooler (CAC) Pump Connector, Harness Side (-) Charge Air Cooler (CAC) Pump Connector, Harness Side
      PUMPPWR - Pin 1 GND - Pin 2
    • Carry out the PCM KOEO self-test.

    Does the voltage cycle to greater than 10 V? 

    Yes No
    INSTALL a new Charge Air Cooler (CAC) Pump. REFER to the appropriate Engine Cooling article, Supercharger Cooling.
    Clear the PCM DTCs. REPEAT the self-test.    		 GO to  KP10.
  10. KP10 CHECK THE CAC VOLTAGE CIRCUIT TO GND 
    • Measure the voltage between:
      (+) Charge Air Cooler (CAC) Pump Connector, Harness Side (-) Vehicle Battery
      PUMPPWR - Pin 1 Negative terminal

    Is the voltage greater than 10 V? 

    Yes No
    GO to  KP11. REPAIR the open circuit. Clear the PCM DTCs.
    REPEAT the self-test.
  11. KP11 CHECK THE INTEGRITY OF THE CAC PUMP GROUND CONNECTION 
    • Charge Air Cooler (CAC) Pump connector disconnected.
    • Measure the resistance between:
      (+) Charge Air Cooler (CAC) Pump Connector, Harness Side (-) Vehicle Battery
      GND - Pin 2 Negative terminal

    Is the resistance less than 5 ohms? 

    Yes No
    GO to  KP12. REPAIR the open circuit. Clear the PCM DTCs.
    REPEAT the self-test.
  12. KP12 CHECK THE VOLTAGE TO THE CAC PUMP RELAY 
    • CAC Relay connector disconnected.
    • Measure the voltage between:
      (+) CAC Relay Connector, Harness Side (-)
      B+ - Pin 3 Ground

    Is the voltage greater than 10 V? 

    Yes No
    GO to  KP13. REPAIR the open circuit. CHECK the fuses.
    Clear the PCM DTCs. REPEAT the self-test.
  13. KP13 CHECK FOR AN OPEN CAC PUMP CIRCUIT 
    • Measure the resistance between:
      (+) CAC Relay Connector, Harness Side (-) Charge Air Cooler (CAC) Pump Connector, Harness Side
      PUMPPWR - Pin 5 PUMPPWR - Pin 1

    Is the resistance less than 5 ohms? 

    Yes No
    INSTALL a new CAC pump relay.
    Clear the PCM DTCs. REPEAT the self-test.    		 REPAIR the open circuit. Clear the PCM DTCs.
    REPEAT the self-test.
  14. KP14 CHECK FOR CORRECT PCM OPERATION 
    • Disconnect all the PCM connectors.
    • Visually inspect for:
      • pushed out pins
      • corrosion
    • Connect all the PCM connectors and make sure they seat correctly.
    • Carry out the PCM self-test.
    • Verify the concern is still present.

    Is the concern still present? 

    Yes No
    INSTALL a new PCM. REFER to FLASH ELECTRICALLY ERASABLE PROGRAMMABLE READ ONLY MEMORY (EEPROM) , Programming the VID Block for a Replacement PCM. The system is operating correctly at this time. The concern may have been caused by a loose or corroded connector.
    GO to PINPOINT TEST Z .
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