Help on overheating 2001 Cobra

Discussion in 'SVT Tech Forum' started by MacDaddy07, Jan 19, 2009.


  1. MacDaddy07

    MacDaddy07 New Member

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    Hotcobra, thanks for the information! Looks like pretty basic troubleshooting, so I assume the information you supplied for a 2003 would also apply to my son's 2001?



    Interesting addendum to the saga of my son's car. He and a friend removed the thermostat. The car has not exceeded 180 degree temp the last few days! The last time we pulled it out, we checked that it would open in a pot of boiling water. It is not a Motocraft part, but is one we bought from AutoZone. I also checked, double checked, and triple checked that we put it in the correct way.

    Weird.

    For now he's running without a thermostat and is pretty happy.
     
    #21
  2. hotcobra03

    hotcobra03 Active Member

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    yes it will be like yous..mine is only slightly different...my 03 has 230k on it today...yes i drive it..if i were you i would do a compression test....these engines are know for valve seat problems from lack of cooling..it can run on 31 valves and not be felt...i just had this problem and from diagnostic on the problem (running hot,cool off ,try again,,got hot,,cool off try again) my problem came out..IT WAS A CRACK IN THE HEAD,combustion was getting into water... i pulled my engine myself and saved big time..cost was 2grand when all was said and done,and i did have the head welded.. if your good with electronics i can send you that stuff for your fan ..really its only nuts and bolts and should be fixable by any backyard mechanic
     
    #22
  3. MacDaddy07

    MacDaddy07 New Member

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    I'm pretty good with electronics, so sure send away! Is it something you can just attach to your reply?

    I've suggested he do a compression and pressure check. He's trying to find someone that can help him with that. I sure hope it isn't a cracked head, no way could he (or I) afford to have that fixed. And fixing it ourselves is way beyond his abilities, and I don't have the time or back!
     
    #23
  4. hotcobra03

    hotcobra03 Active Member

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    start at x-40 for no fan,,,,than x80 starts for fan wont shut off ,,,,i had to shorten this for posting its too big..if you want more pm me an email address to send it too
    --------------------------------------------------------------------------------
    X: Constant Control Relay Module (CCRM) X: Introduction



    X40 ELECTRIC COOLING FAN FUNCTIONAL CHECK
    Note: For the proper results of these pinpoint tests, no DTCs must have been present during PCM Quick Test.

    Key on, engine off.
    Access Output Test Mode on scan tool.
    Command of the cooling fan on and check for fan operation. For two speed fan applications, check both fan speeds (wait 30 seconds after commanding high speed fan on).
    Does the fan operate (all speeds)?
    Yes No
    KEY OFF. Cooling fan circuits OK. RETURN to Section 3 chart. COMMAND cooling fan off. REMAIN in Output Test Mode. GO to X41 .

    X41 ELECTRIC COOLING FAN CONCERN: DID THE FAN OPERATE AT ANY SPEED?
    For 3.8L Mustang, GO to X42 .
    During the operational check of both fan speeds, did the fan operate at any speed?
    Yes No
    Only one fan speed is operational.

    GO to X50 . Cooling fan will not operate at any speed. GO to X42 .

    X42 COOLING FAN WILL NOT OPERATE AT ANY SPEED: COMMAND FAN ON (HIGH SPEED FOR TWO-SPEED APPLICATIONS) AND CHECK FOR VOLTAGE AT FAN
    Key on, engine off.
    Disconnect cooling fan.
    Command fan on (high speed for two speed fan applications).
    Measure voltage between the (HIGH) FAN PWR circuit at the cooling fan harness connector and chassis ground.
    Is voltage greater than 10.0 volts?
    Yes No
    KEY OFF. Power is being supplied to fan. GO to X45 . KEY OFF. GO to X43 .

    X43 CHECK FOR B+ TO FAN CONTROL RELAYS IN CCRM
    Disconnect CCRM.
    Measure voltage at pins 3 and 4 of the CCRM harness connector.
    Is voltage greater than 10.0 volts?
    Yes No
    GO to X44 . B+ fault. CHECK condition of related fuses. If OK, REPAIR open circuit. If fuse is damaged, CHECK B+ and FAN PWR circuits for short to ground before replacing.

    X44 CHECK FOR OPEN FAN PWR CIRCUIT BETWEEN CCRM AND COOLING FAN
    For 3.8L Mustang:
    Measure resistance of FAN PWR circuit between pin 2 of the CCRM harness connector and the fan harness connector.
    All others:
    Measure resistance of HIGH FAN PWR circuit between pin 6 of the CCRM harness connector and the fan harness connector.
    Measure resistance of LOW FAN PWR circuit between pin 2 of the CCRM harness connector and the fan harness connector.
    Is each resistance less than 7.0 ohms?
    Yes No
    For 3.8L Mustang:

    GO to X70 .

    All others:

    REPLACE CCRM. VERIFY FAN PWR circuit(s) are not short to ground. REPAIR open circuits(s).

    X45 CHECK FOR OPEN COOLING FAN GROUND CIRCUIT
    Disconnect scan tool from DLC.
    Measure resistance of ground circuit between the cooling fan harness connector and chassis ground.
    Is resistance less than 5.0 ohms?
    Yes No
    REPLACE fan. REPAIR open circuit.

    X50 DETERMINE WHICH FAN SPEED IS OPERATIONAL
    Was the low speed fan operational?
    Yes No
    High speed fan inoperative.

    GO to X65 . Low speed fan inoperative.

    GO to X51 .

    X51 LOW SPEED FAN INOPERATIVE: COMMAND LOW SPEED FAN ON AND CHECK FOR VOLTAGE TO COOLING FAN
    Key on, engine off.
    Disconnect cooling fan.
    Command low speed fan on.
    Measure LOW FAN PWR circuit voltage at the cooling fan harness connector.
    Is voltage greater than 10.0 volts?
    Yes No
    KEY OFF.

    For 4.6L Mustang:

    GO to X54 .

    All others:

    REPLACE fan. KEY OFF. GO to X52 .

    X52 CHECK FOR OPEN LOW FAN PWR CIRCUIT BETWEEN CCRM AND FAN
    Disconnect CCRM.
    Measure resistance of the LOW FAN PWR circuit between the cooling fan harness connector and pins 1 and 2 of the CCRM harness connector.
    Are both resistances less than 5.0 ohms?
    Yes No
    GO to X70 . REPAIR open circuit.

    X54 CHECK FOR OPEN DROPPING RESISTOR ON FAN SHROUD ASSEMBLY
    Measure resistance between the LOW FAN PWR and HIGH FAN PWR pins of the fan shroud assembly.
    Is resistance less than 6.0 ohms?
    Yes No
    REPLACE fan. Verify condition of dropping resistor, replace as necessary (use care when removing resistor from mounts). If OK, replace fan assembly.

    X65 HIGH SPEED FAN INOPERATIVE: COMMAND HIGH SPEED FAN ON AND CHECK FOR VOLTAGE TO COOLING FAN
    Key on, engine off.
    Disconnect cooling fan.
    Command high speed fan on.
    Measure HIGH FAN PWR circuit voltage at the cooling fan harness connector.
    Is voltage greater than 10.5 volts?
    Yes No
    KEY OFF. REPLACE fan. KEY OFF. GO to X66 .

    X66 CHECK FOR OPEN HIGH FAN PWR CIRCUIT
    Disconnect CCRM.
    Measure resistance of HIGH FAN PWR circuit between the cooling fan harness connector and pin 6 of the CCRM harness connector.
    Is resistance less than 5.0 ohms?
    Yes No
    GO to X70 . REPAIR open circuit.

    X70 IS SCAN TOOL CAPABLE OF VIEWING PIDS WHILE IN OUTPUT TEST MODE?
    Note: The symptom low speed fan or high speed fan inoperative can be caused by a primary circuit fault, even though a DTC was not set.

    Is scan tool being used capable of viewing PIDS while in Output Test Mode?
    Yes No
    GO to X71 . For low speed fan inoperative (fan inoperative for 3.8L Mustang):

    GO to X73 .

    For high speed fan inoperative.

    GO to X16 .

    X71 CHECK OPERATION OF LOW SPEED FAN OR HIGH SPEED FAN PRIMARY CIRCUITS
    Reconnect CCRM and cooling fan.
    Key on, engine off.
    Access Output Test Mode on scan tool.
    For low speed fan inoperative (fan inoperative for 3.8L Mustang):
    Access LFC and LFCF PIDs.
    With LFC PID off (low speed fan commanded off by PCM), the LFCF PID must indicate no fault (or NO).
    Command the Low Speed Fan on (the LFC PID will now be on).
    The LFCF PID must still indicate no fault.
    For high speed fan inoperative:
    Access HFC and HFCF PIDs.
    With HFC PID off (high speed fan commanded off by PCM), the HFCF PID must indicate no fault (or NO).
    Command the high speed fan on (the HFC PID will now be on).
    The HFCF PID must still indicate no fault (or NO).
    Does the HFCF or LFCF PID indicate a fault (or YES) with the fan commanded on or off?
    Yes No
    KEY OFF. An HFC or LFC primary fault is detected.

    If the HFCF PID indicated a fault:

    GO to X15 and follow DTC P0481 diagnosis.

    If the LFCF PID indicated a fault:

    GO to X20 and follow DTC P0480 diagnosis. Primary circuits OK. REPLACE CCRM. VERIFY applicable FAN PWR circuit is not short to ground.

    X73 CHECK FC/LFC CIRCUIT FOR SHORT TO GROUND IN HARNESS
    Disconnect scan tool from DLC.
    Disconnect PCM.
    Measure resistance between pin 14 of the CCRM harness connector and chassis ground.
    Is resistance greater than 10,000 ohms?
    Yes No
    REPLACE CCRM. VERIFY applicable FAN PWR circuit is not shorted to ground. REPAIR short circuit.

    X80 LOW AND/OR HIGH SPEED COOLING FAN ALWAYS RUNS (NO DTCS): VERIFY FAN IS NOT ON BECAUSE OF A/C HIGH PRESSURE SWITCH INPUT TO PCM
    Start engine.
    Access ACP PID.
    Is the ACP PID "CLOSED"?
    Yes No
    The PCM will turn the cooling fan on when the A/C high pressure switch input is "closed". Leave engine running. GO to X81 . Input OK. GO to X82 .

    X81 CHECK A/C HIGH PRESSURE SWITCH (THE MEDIUM PRESSURE, NORMALLY OPEN CONTRACTS)
    Disconnect A/C high pressure switch.
    Again, view ACP PID.
    Is the ACP PID still "CLOSED"?
    Yes No
    KEY OFF. GO to X135 (to check A/C high pressure switch input to PCM). KEY OFF. RECONNECT A/C high pressure switch. REFER to the Climate Control System, Section 412 of the Workshop Manual to check for proper A/C high pressure switch function, over-pressurized A/C system and other checks as directed.

    X82 DISCONNECT CCRM AND CHECK IF FAN STILL RUNS
    Accessories off (A/C, blower, lamps).
    Key on, verify cooling fan always on symptom.
    Key off.
    Disconnect CCRM.
    Key on, engine off.
    Is cooling fan still on?
    Yes No
    KEY OFF.

    For 3.8L Mustang:

    REPAIR FAN PWR circuit short to power.

    For all others:

    GO to X83 . Key off. GO to X84 .



    X83 CHECK LOW FAN PWR AND HIGH FAN PWR CIRCUITS FOR SHORT TO POWER
    Disconnect cooling fan.
    Key on, engine off.
    Check for voltage on both the LOW FAN PWR and HIGH FAN PWR circuits at the cooling fan harness connector.
    Are both voltages less than 1.0 volt?
    Yes No
    KEY OFF. No fault is indicated at this time. VERIFY results of previous test steps. If OK, RECONNECT all components and RETURN to Section 3 for further diagnosis of this or any other symptom. REPAIR short circuit.

    X84 CHECK OPERATION OF LOW SPEED FAN OR HIGH SPEED FAN PRIMARY CIRCUITS
    Note: The symptom cooling fan always runs can be caused by a primary circuit fault, even though a DTC was not set. This step will check the primary circuit operation.

    Reconnect CCRM.
    Key on, engine off.
    Access LFC and LFCF PIDs. With LFC PID off (low speed fan commanded off by PCM), the LFCF PID must indicate no fault (or NO).
    For all except 3.8L Mustang, access HFC and HFCF PIDs. With HFC PID off (high speed fan commanded off by PCM), the HFCF PID must indicate no fault (or NO).
    Does the HFCF or LFCF PID indicate a fault (or YES) with the fan commanded off?
    Yes No
    KEY OFF. An HFC or LFC primary circuit fault is detected.

    If the HFCF PID indicated a fault:

    GO to X15 and follow DTC P0481 diagnosis.

    If the LFCF PID indicated a fault:

    GO to X20 and follow DTC P0480 diagnosis. Primary circuits OK. REPLACE CCRM.

    X98 LACK OF COOLING (A/C)/A/C NOT FUNCTIONING: CHECK FOR VOLTAGE TO A/C CLUTCH
    Note: If the A/C clutch will engage, follow the "YES" Action to Take of this test step. If not, or unsure, continue this test step.

    Key off.
    Disconnect A/C cycling switch.
    Install a jumper wire in the A/C cycling switch harness connector (to complete the circuit).
    Disconnect A/C clutch.
    Connect digital multimeter between the power pin and ground pin at the A/C clutch vehicle harness connector.
    Start engine.
    Turn A/C on, wait 15 seconds.
    Check voltage reading.
    After testing, turn key off and reconnect A/C clutch.
    Was voltage greater than 10.5 volts?
    Yes No
    REMOVE jumper. RECONNECT A/C cycling switch.

    For all except 3.8L Mustang with the symptom "poor A/C system performance in hot ambient temperature":

    GO to X145 to check A/C high pressure switch input to PCM.

    All others:

    REFER to the Climate Control System, Section 412 of the Workshop Manual to diagnose symptom. Also be aware that if the engine coolant temperature is detected high, the PCM will disengage the A/C clutch. No voltage to A/C clutch. GO to X99 .

    X99 CHECK ACCS INPUT TO PCM WITH A/C ON
    Start engine.
    A/C on.
    Access and view ACCS PID.
    After testing, remove jumper reconnect A/C cycling switch and turn key OFF.
    Was the ACCS PID "ON"?
    Yes No
    GO to X110 . The PCM is not receiving the ACCS signal, and as a result will not allow the A/C to turn on. GO to X100 .

    X100 ACCS PID OFF WITH A/C ON: CHECK FOR VOLTAGE TO A/C CYCLING SWITCH
    Key on, engine off.
    Disconnect A/C cycling switch.
    A/C demand switch to A/C on.
    Measure voltage at the A/C demand switch side of the A/C cycling switch harness connector.
    Is voltage greater than 10.5 volts?
    Yes No
    KEY OFF. GO to X101 . KEY OFF. REFER to the Climate Control System, Section 412 in the Workshop Manual to check for causes of no voltage to the A/C cycling switch.

    X101 CHECK IF A/C CYCLING SWITCH CONTACTS ARE CLOSED
    Measure resistance of the A/C cycling switch contacts at the A/C cycling switch connector.
    Is resistance less than 5.0 ohms?
    Yes No
    GO to X102 . REFER to the Climate Control System, Section 412 in the Workshop Manual to check the operation of the A/C cycling switch and proper refrigerant charge. REPAIR as necessary.

    X102 CHECK FOR VOLTAGE TO DUAL FUNCTION A/C HIGH PRESSURE SWITCH
    Reconnect A/C cycling switch.
    Disconnect A/C high pressure switch.
    Key on, engine off.
    A/C on.
    Measure voltage on the A/C demand switch pin at the A/C high pressure switch harness connector.
    Is voltage greater than 10.5 volts?



    Yes No
    KEY OFF. GO to X103 . REPAIR open between A/C cycling switch and A/C high pressure switch.

    X103 CHECK RESISTANCE OF A/C HIGH PRESSURE SWITCH HIGH PRESSURE CONTACTS
    Measure resistance of the normally closed A/C high pressure switch high pressure contacts.
    Is resistance less than 5.0 ohms?
     
    #24
  5. hotcobra03

    hotcobra03 Active Member

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    check all fuses
     
    #25
  6. hotcobra03

    hotcobra03 Active Member

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    fuse box

    fuse box
     
    #26
  7. hotcobra03

    hotcobra03 Active Member

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    ccrm/aux fuse box

    ccrm is located behind air box inside of rightside fender,,the aux fuse box is located in the same place next to maf on fender
     
    #27

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