DTC P1479[AJ (3.0L Duratec)]
id0102a4825800
|
DTC P1479 |
Cooling fan relay No.1 and No.3 primary circuit failure |
|---|---|
|
DETECTION CONDITION
|
• The PCM monitors that the cooling fan relay No.1 and No.3 primary circuit voltage at PCM terminal 46. The PCM detects excessive current draw (while PCM grounds circuit) or no voltage (while PCM does not ground circuit), the PCM determines that the cooling fan relay No.1 and No.3 primary circuits failure.
|
|
POSSIBLE CAUSE
|
• Open circuit in wiring between cooling fan relay No.1 terminal B and PCM terminal 46
• Short to power in wiring between cooling fan relay No.1 terminal B and PCM terminal 46
• Short to ground in wiring between cooling fan relay No.1 terminal B and PCM terminal 46
• Open circuit in wiring between cooling fan relay No.3 terminal B and PCM terminal 46
• Short to power in wiring between cooling fan relay No.3 terminal B and PCM terminal 46
• Short to ground in wiring between cooling fan relay No.3 terminal B and PCM terminal 46
• Open circuit in wiring between cooling fan relay No.1 terminal D and ignition switch
• Open circuit in wiring between cooling fan relay No.3 terminal D and ignition switch
• Damaged cooling fan relay No.1
• Damaged cooling fan relay No.3
• Damaged PCM
|
Diagnostic procedure
|
STEP |
INSPECTION |
ACTION |
|
|---|---|---|---|
|
1
|
VERIFY FREEZE FRAME DATA HAS BEEN RECORDED
• Has FREEZE FRAME DATA been recorded?
|
Yes
|
Go to the next step.
|
|
No
|
Record the FREEZE FRAME DATA on the repair order, then go to next step.
|
||
|
2
|
VERIFY SERVICE INFORMATION AVAILABILITY
• Verify related Service Information availability.
• Is any related Service Information available?
|
Yes
|
Perform repair or diagnosis according to the available Service Information.
• If the vehicle is not repaired, go to next step.
|
|
No
|
Go to the next step.
|
||
|
3
|
INDETIFY TRIGGER DTC FOR FEEZE FRAME DATA
• Is DTC P1479 on FREEZE FRAME DATA?
|
Yes
|
Go to the next step.
|
|
No
|
Go to FREEZE FRAME DATA DTC inspection.
(See DTC TABLE[AJ (3.0L Duratec)].)
|
||
|
4
|
INSPECT HIGH SPEED FAN CONTROL (HFC) CIRCUIT FOR INTERMITTENT FAILURE
• Rerun KOEO, KOER self test and Continuous Memory DTCs.
• Is DTC P1479 present in Continuous Memory self test only?
|
Yes
|
Go to Step 10.
|
|
No
|
Go to the next step.
|
||
|
5
|
CHECK VPWR VOLTAGE TO cooling fan relay No. 2
• Disconnect cooling fan relay No.1 and No.3.
• Turn the ignition switch to the ON position.
• Start the engine.
• Measure VPWR circuit voltages at cooling fan relay No.1 and No.3 harness connector terminal B.
• Is the voltage greater than 10.5 V?
|
Yes
|
Go to the next step.
|
|
No
|
Repair open circuit, then go to Step 12.
|
||
|
6
|
CHECK FOR HFC CIRCUIT CYCLING
• Turn the ignition switch to the ON position.
• Connect a non-powered test lamp between VPWR circuit and the HFC circuit at cooling fan relay No.1 and No.3 harness connector terminal B to D.
• Access Output Test Mode HFC PID on the M-MDS.
• While observing test lamp, command the HFC PID on and off.
• Does the test lamp turned on and off when the cooling fan output is commanded on and off?
|
Yes
|
Replace malfunctioning cooling fan relay No.1, No.3, then go to Step 12.
|
|
No
|
Go to the next step.
|
||
|
7
|
CHECK HFC CIRCUIT FOR SHORT TO POWER IN HARNESS
• Disconnect PCM.
• Turn the ignition switch to the ON position.
• Measure voltage between cooling fan relay No.1 and No.3 terminal D at harness side connector and ground.
• Is the voltage less than 1.0 V?
|
Yes
|
Go to the next step.
|
|
No
|
Repair short circuit, then go to Step 12.
|
||
|
8
|
CHECK HFC CIRCUIT FOR SHORT TO GROUND HARNESS
• Disconnect M-MDS to DLC-2.
• Measure resistance between cooling fan relay No.1 and No.3 terminal D at harness side connector and ground.
• Is resistance greater than 10.0 ohms?
|
Yes
|
Go to the next step.
|
|
No
|
Repair short to ground circuit, then go to Step 12.
|
||
|
9
|
CHECK FOR OPEN HFC CIRCUIT
• Measure the resistance of the HFC circuit between the PCM terminal 46 and cooling fan relay No.1 and No.3 connector terminal B at harness side connector.
• Is resistance less than 5.0 ohms?
|
Yes
|
Replace PCM, then go to Step 12.
|
|
No
|
Repair open circuit, then go to Step 12.
|
||
|
10
|
CHECK HFC CORCUIT FOR OPEN OR SHORT TO POWER
• A/C and defroster off.
• Disconnect cooling fan connector (both applications with two fans).
• Connect a non-powered test lamp between (HIGH) FAN PWR circuit and ground circuit at the cooling fan harness connector (either one for applications with two fans).
• Turn the ignition switch to the ON position.
• Access Output Test Mode HFC PID on the M-MDS.
• Command HFC PID to on.
• Observe test lamp for an indication of a fault while completing the following (the lamp will turn off when a fault is detected, indicating an open or short to power):
• Is fault indicated?
|
Yes
|
Isolate fault and repair, repair or replace malfunctioning part.
Then go to Step 12.
|
|
No
|
Go to the next step.
|
||
|
11
|
CHECK HFC CIRCUIT FOR SHORT TO GROUND
• Turn the ignition switch to the ON position.
• Command HFC PID to off using Output Test Mode on the M-MDS.
• Observe the test lamp for an indication of a fault while completing the following (the lamp will turn on when a fault is detected, indicating HFC circuit short to ground):
• Is fault indicated?
|
Yes
|
Isolate fault and repair, repair or replace malfunctioning part.
Then go to the next step.
|
|
No
|
Intermittent concern exists, go to Intermittent Troubleshooting Procedure.
|
||
|
12
|
VERIFY TROUBLESHOOTING OF DTC P1479 COMPLETED
• Make sure to reconnect all disconnected connectors.
• Clear the DTC from the PCM memory using the M-MDS.
• Perform KOEO/KOER self test.
• Is the PENDING CODE same DTC present?
|
Yes
|
Replace PCM, then go to next step.
|
|
No
|
Go to the next step.
|
||
|
13
|
VERIFY AFTER REPAIR PROCEDURE
• Perform "AFTER REPAIR PROCEDURE".
• Is there any DTC present?
|
Yes
|
Go to applicable DTC inspection.
(See DTC TABLE[AJ (3.0L Duratec)].)
|
|
No
|
Troubleshooting completed.
|
||