Diagnostic Aids

CCRM interfaces with the EEC-V system to provide control for fuel pump, cooling fan and A/C compressor clutch. CCRM also contains EEC-V power relay, which provides battery power (VPWR) to the Powertrain Control Module (PCM) and EEC-V system. Perform this test only when instructed by QUICK TEST  or if directed by a circuit test. This test is only intended to diagnose the following:

• CCRM including EEC power relay, Fan Control/Low Fan Control (FC/LFC) relay.
• High Fan Control (HFC) relay.
• Harness Circuits (B +, FC, LFC, HFC, ACCS, VPWR (to CCRM), Power-To-A/C Clutch and Power-To-Low/High Speed Fan).
• Powertrain Control Module (PCM). To prevent replacing good components, be aware the following non-EEC related components or systems may be at fault: a: A/C system. b: Starting and charging system.
  NOTE: Use the following illustration for CCRM harness connector terminal identification. See Fig 1 . For CCRM circuit identification, see wiring diagrams in WIRING DIAGRAMS  .
  Fig 1: CCRM Harness Connector Terminals (Wiring Harness Side Shown)

  Courtesy of FORD MOTOR CO.
  NOTE: A break in step numbering sequence occurs at this point. Procedure starts at step 15). No test procedures have been omitted.

1. 15) DTC P1479 - Check High Fan Control (HFC) Relay
   
   DTC P1479 indicates HFC primary circuit failure. Possible causes are:
   • Open or shorted HFC circuit.
   • Faulty CCRM.
   • Faulty PCM.
   NOTE: On one-speed fan applications, disregard DTC P1479.

   Turn ignition off. Disconnect CCRM harness connector. Using an ohmmeter, measure resistance between pins No. 17 and 24 of CCRM. Resistance should be 65-100 ohms. Measure resistance between pin No. 17 and pins No. 1-11, 13, 15 and 21. Measure resistance between pin No. 17 and CCRM case. Each resistance should be greater than 1000 ohms. If all resistance checks are okay, go to next step. If resistance checks are not as specified, replace CCRM. Repeat the QUICK TEST  .

2. 16) Check HFC Circuit Resistance
   
   Turn ignition off. Disconnect CCRM and PCM harness connectors. Check for corroded, damaged or backed-out terminal pins. Repair as necessary. Install breakout box, leaving PCM disconnected. Using an ohmmeter, measure resistance between CCRM terminal No. 17 and breakout box test pin No. 17. If resistance is less than 5 ohms, go to next step. If resistance is not as specified, repair open in HFC circuit. Remove breakout box and repeat QUICK TEST  .
3. 17) Check HFC Circuit For Short To Power
   
   Leave CCRM and PCM disconnected. Turn ignition on. Using a voltmeter, measure voltage between negative battery terminal and breakout box test pin No. 17. If reading is less than one volt, turn ignition off and go to next step. If reading is not as specified, repair short to power and repeat QUICK TEST  .
4. 18) Check HFC Circuit For Short To Ground
   
   Turn ignition off. Leave CCRM and PCM disconnected. Disconnect scan tool. Using an ohmmeter, measure resistance between breakout box test pin No. 17 and test pins No. 51, 103 and 91. If all measurements are greater than 10 k/ohms, replace PCM. If any measurement is not as specified, repair short to ground in HFC circuit. Remove breakout box and repeat QUICK TEST  .
   NOTE: A break in step numbering sequence occurs at this point. Procedure skips from step 18) to step 20). No test procedures have been omitted.
5. 20) DTC P1474 - Check Fan Operation
   
   DTC P1474 indicates primary circuit failure in Low Fan Control (LFC) circuit, or Fan Control (FC) circuit for one-speed cooling fan systems. Possible causes are:
   • Open or shorted FC/LFC circuit.
   • Faulty CCRM.
   • Faulty PCM.

   Turn ignition on. If cooling fan runs continuously, go to step 24). If cooling fan does not run continuously, go to next step.

6. 21) Check LFC Circuit For Short To Ground
   
   Turn ignition off. Disconnect CCRM harness connector. Disconnect scan tool. Disconnect PCM harness connector. Check for corroded, damaged or backed-out terminal pins. Repair as necessary. Install breakout box, leaving PCM disconnected. Using an ohmmeter, measure resistance between breakout box pin No. 45 and test pins No. 51, 91 and 103. If each reading is greater than 10 k/ohms, go to next step. If any reading is not as specified, locate and repair short to ground in LFC circuit. Reconnect all components and repeat QUICK TEST  .
7. 22) Check Fan Operation
   
   Turn ignition off. Connect CCRM. Leave PCM disconnected. Turn ignition on, engine off. If cooling fan runs continuously, replace PCM and repeat QUICK TEST  . If cooling fan does not run continuously, replace CCRM and repeat QUICK TEST  .
   NOTE: A break in step numbering sequence occurs at this point. Procedure skips from step 22) to step 24). No test procedures have been omitted.
8. 24) Check LFC Circuit Resistance
   
   Turn ignition off. Disconnect CCRM harness connector. Disconnect PCM harness connector. Check for corroded, damaged or backed-out terminal pins. Repair as necessary. Install breakout box, leaving PCM disconnected. Using an ohmmeter, measure resistance between breakout box test pin No. 45 and CCRM terminal No. 14. If resistance is less than 5 ohms, go to next step. If resistance is not as specified, locate and repair open in FC or LFC circuit. Reconnect all components and repeat QUICK TEST  .
9. 25) Check LFC Circuit For Short To Power
   
   Turn ignition on. Using a voltmeter, measure voltage between breakout box test pin No. 45 and negative battery terminal. If reading is less than one volt, go to next step. If reading is not as specified, locate and repair short to power in FC or LFC circuit. Reconnect all components and repeat QUICK TEST  .
10. 26) LFC Circuit Fault Isolation Check
    
    Turn ignition on. Using a fused jumper wire, jumper between breakout box test pin No. 45 and test pin No. 77. If cooling fan runs continuously, replace CCRM and repeat QUICK TEST  . If cooling fan does not run continuously, replace PCM and repeat the QUICK TEST  .
    NOTE: A break in step numbering sequence occurs at this point. Procedure skips from step 26) to step 30). No test procedures have been omitted.
11. 30) Continuous Memory DTC P1474 - Check LFC Circuit For Open Circuit Or Short To Power
    
    A Continuous Memory DTC P1474 indicates that circuit failure has occurred on Low Fan Control (LFC) circuit. If DTC P1474 is present, turn ignition off. Disconnect cooling fan harness connector. Check for corroded, damaged or backed-out terminal pins. Repair as necessary. Connect a test light between cooling fan harness Power-To-Low Speed Fan circuit and ground. Turn ignition on. Test light should be off. Check for indication of fault (test light blinks or comes on) while performing the following:
    • Shake and bend LFC circuits between CCRM and PCM.
    • Lightly tap CCRM to simulate road shock.

    Turn ignition off. If fault is indicated, isolate and repair as necessary. Repeat QUICK TEST  . If fault is not indicated, go to next step.

12. 31) Check LFC Circuit For Short To Ground
    
    Leave cooling fan harness connector disconnected. Leave scan tool and test light connected. Turn ignition on. Access OUTPUT TEST MODE on scan tool. Command low speed fan on. Test light should be on. Check for indication of fault (test light blinks or goes off) while performing the following:
    • Shake and bend FC/LFC circuits between CCRM and PCM.
    • Lightly tap CCRM to simulate road shock.

    Turn ignition off. If fault is indicated, isolate and repair as necessary. Repeat QUICK TEST  . If fault is not indicated, problem may be intermittent. Go to CIRCUIT TEST Z in the TESTS W/CODES article in the ENGINE PERFORMANCE section.

    NOTE: A break in step numbering sequence occurs at this point. Procedure skips from step 31) to step 35). No test procedures have been omitted.
    NOTE: On one-speed fan applications, disregard DTC P1479.
13. 35) DTC P1479
    
    A Continuous Memory DTC P1479 indicates that High Fan Control (HFC) circuit failure has occurred. Turn ignition off. Leave scan tool connected. Disconnect cooling fan harness connector. Check for corroded, damaged or backed-out terminal pins. Repair as necessary. Connect a test light between ground and Power-To-High Speed Fan circuit at cooling fan harness connector. Turn ignition on, engine off. Access OUTPUT TEST MODE on scan tool. Command high speed fan on. Test light should be on. Check for indication of fault (test light blinks or goes off) while performing the following:
    • Shake and bend HFC circuit between CCRM and PCM.
    • Lightly tap CCRM to simulate road shock.

    Turn ignition off. If fault is indicated, isolate and repair as necessary. Repeat QUICK TEST  . If fault is not indicated, go to next step.

14. 36) Check HFC Circuit For Short To Ground
    
    Leave cooling fan harness connector disconnected. Leave scan tool and test light connected. Turn ignition on, engine off. Command high speed fan off. Test light should be off. Check for indication of fault (test light blinks or comes on) while performing the following:
    • Shake and bend HFC circuit between CCRM and PCM.
    • Lightly tap CCRM to simulate road shock.

    Turn ignition off. If fault is indicated, isolate and repair as necessary. Repeat QUICK TEST  . If fault is not indicated, problem may be intermittent. Go to CIRCUIT TEST Z in the TESTS W/CODES article in the ENGINE PERFORMANCE section.

    NOTE: A break in step numbering sequence occurs at this point. Procedure skips from step 36) to step 40). No test procedures have been omitted.
15. 40) Check Cooling Fan Operation
    
    During operational check of both fan speeds, if fan did not operate at any speed, stay in OUTPUT TEST MODE and go to next step. If fan operated at only one speed, go to step 50).
16. 41) Cooling Fan Does Not Operate At Any Speed
    
    Turn ignition on. Disconnect cooling fan motor. Using scan tool, command high speed fan on. Using a voltmeter, measure voltage between ground and Power-To-High Speed Fan circuit terminal at cooling fan harness connector. If reading is greater than 10 volts, go to step 45). If reading is not as specified, go to next step.
17. 42) Check B + Circuit To Fan Relays
    
    Turn ignition off. Ensure cooling fan is disconnected. Disconnect CCRM. Using a voltmeter, measure voltage between negative battery terminal and terminals No. 3 and 4 of CCRM harness connector. If each reading is greater than 10 volts, go to next step. If any reading is not as specified, fault exists in B + circuit. Check cooling fan related fuse/fuse links. If fuse/fuse link is blown, check for short to ground in B + circuit. If fuse/fuse link is okay, check for open B + circuit. Repair as necessary. Reconnect all components and recheck system operation.
18. 43) Check Power To Fan(s) Circuit
    
    Turn ignition off. Ensure CCRM and cooling fan is disconnected. Using an ohmmeter, measure resistance of Power- To-High Fan circuit between cooling fan harness connector and terminal No. 6 at CCRM harness connector. Also, measure resistance of Power-To-Low Fan circuit between cooling fan and terminal No. 2 of CCRM harness connector. If resistance is less than 7 ohms, replace CCRM. Reconnect all components and recheck system operation. If any reading is 7 ohms or more, locate and repair open circuit(s) between cooling fan motor and CCRM.
    NOTE: A break in step numbering sequence occurs at this point. Procedure skips from step 43) to step 45). No test procedures have been omitted.
19. 45) Check Cooling Fan Ground Circuit
    
    Turn ignition off. Ensure cooling fan is disconnected. Disconnect scan tool. Using an ohmmeter, measure resistance between ground and ground circuit terminal at cooling fan harness connector. If resistance is less than 5 ohms, replace fan motor. If reading is not as specified, locate and repair open ground circuit. Reconnect all components and recheck system operation.
    NOTE: A break in step numbering sequence occurs at this point. Procedure skips from step 45) to step 50). No test procedures have been omitted.
20. 50) Determine Which Fan Speed Is Operational
    
    If low speed fan is functioning properly, but high speed fan is inoperative, go to step 65). If high speed fan is functioning properly but low speed fan is inoperative, go to next step.
21. 51) Low Speed Cooling Fan Inoperative
    
    Turn ignition on. Remain in OUTPUT TEST MODE. Disconnect cooling fan. Command low speed fan on. Using a voltmeter, measure voltage between ground circuit terminal and Power-To-Low Fan circuit terminal at cooling fan harness connector. If reading is greater than 10 volts, replace fan motor. Reconnect all components and recheck system operation. If reading is not as specified, go to next step.
22. 52) Check Power-To-Low Fan Circuit Resistance
    
    Turn ignition off. Disconnect CCRM. Using an ohmmeter, measure resistance of Power-To-Low Fan circuit between cooling fan harness connector and terminals No. 1 and 2 of CCRM harness connector. If both resistances are less than 5 ohms, go to next step. If both resistances are not as specified, repair open in Power-To-Low Fan circuit. Reconnect all components and recheck system operation.
23. 53) Check Low Speed Fan Primary Circuits
    
    Turn ignition off. Reconnect the CCRM and cooling fan harness connectors. Disconnect the PCM. Check for corroded, damaged or backed-out terminal pins. Repair terminal pins as necessary. Install breakout box and scan tool. Turn ignition on, engine off. Using a voltmeter, measure voltage between the breakout box test pin No. 45 and test pin No. 77. Note voltage. Access OUTPUT TEST MODE on scan tool. Command low speed fan on. Measure voltage at specified test pins once more. If voltage changed more than 6 volts when low speed fan was commanded on, replace CCRM. Reconnect all components and recheck system operation. If voltage did not change, go to step 20).
    NOTE: A break in step numbering sequence occurs at this point. Procedure skips from step 53) to step 65). No test procedures have been omitted.
24. 65) High Speed Cooling Fan Inoperative
    
    Turn ignition on. With scan tool still connected and still in OUTPUT TEST MODE, disconnect cooling fan. Command high speed fan on. Using a voltmeter, measure voltage between ground and Power-To-High Fan circuit terminal at cooling fan harness connector. If voltage is 10.5 volts or less, go to next step. If reading is greater than 10.5 volts, replace fan motor. Reconnect all components and recheck system operation. If reading is not as specified, go to next step.
25. 66) Check Power-To-High Fan Circuit Resistance
    
    Turn ignition off. Using an ohmmeter, measure resistance between Power-To-High Fan circuit terminal at cooling fan harness connector and terminals No. 6 at CCRM wiring harness connector. If resistance is less than 5 ohms, go to step 70). If resistance is not as specified, repair open in Power-To-High Fan circuit. Reconnect all components and recheck system operation.
    NOTE: A break in step numbering sequence occurs at this point. Procedure skips from step 66) to step 70). No test procedures have been omitted.
26. 70) Check High Speed Fan Primary Circuits
    
    Turn ignition off. Reconnect CCRM and cooling fan harness connectors. Disconnect PCM. Check for corroded, damaged or backed-out terminal pins. Repair as necessary. Install breakout box and scan tool. Turn ignition on, engine off. Using a voltmeter, measure voltage between breakout box test pin No. 17 and test pin No. 77. Note voltage. Access OUTPUT TEST MODE on scan tool. Command high speed fan on. Wait 10 seconds. Measure voltage at specified test pins once more. If voltage changed more than 6 volts when high speed fan was commanded on, replace CCRM. Reconnect all components and recheck system operation. If voltage did not change, go to step 15).
    NOTE: A break in step numbering sequence occurs at this point. Procedure skips from step 70) to step 80). No test procedures have been omitted.
27. 80) Cooling Fan Always Runs
    
    Turn all accessories off. Turn ignition on. Verify that cooling fan is always on. Turn ignition off. Disconnect CCRM. Turn ignition on. If cooling fan remains on, go to next step. If cooling fan does not remain on, go to step 83).
28. 81) Check For Short To Power
    
    Turn ignition off. Disconnect cooling fan and CCRM harness connectors. Using a voltmeter, measure voltage between ground and Power-To-Low Fan circuit, and Power-To-High Fan circuit at cooling fan motor harness connector. If both readings are less than one volt, problem is intermittent and cannot be duplicated at this time. If any reading is one volt or more, locate and repair short to power in Power-To-Low Fan circuit or Power-To-High Fan circuit. Reconnect all components and recheck system operation.
    NOTE: A break in step numbering sequence occurs at this point. Procedure skips from step 81) to step 83). No test procedures have been omitted.
29. 83) Check Cooling Fan Primary Circuits
    
    Turn ignition off. Reconnect CCRM. Disconnect PCM. Check for corroded, damaged or backed-out terminal pins. Repair as necessary. Install breakout box and scan tool. Turn ignition on, engine off. Perform the following as indicated:

    • One-Speed Fan Applications
      
      Using a voltmeter, measure voltage between breakout box test pin No. 45 and test pin No. 77. Note voltage. Access OUTPUT TEST MODE on scan tool. Command low speed fan on. Measure voltage at specified test pins once more. If voltage changed more than 6 volts when low speed fan was commanded on, replace CCRM. Reconnect all components and recheck system operation. If voltage did not change, go to step 20).
    • Two-Speed Fan Applications
      
      Using a voltmeter, measure voltage between breakout box test pin No. 17 and test pin No. 77. Note voltage. Access OUTPUT TEST MODE on scan tool. Command high speed fan on. Wait 10 seconds. Measure voltage at specified test pins once more. If voltage changed more than 6 volts when high speed fan was commanded on, replace CCRM. Reconnect all components and recheck system operation. If voltage did not change, go to step 15).