DTC P1474[AJ (3.0L Duratec)]

id0102a4825600

DTC P1474

Cooling fan relay No.2 primary circuit failure
DETECTION CONDITION
•  The PCM monitors that the cooling fan relay No.2 primary circuit voltage at PCM terminal 28. 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.2 primary circuit failure.
POSSIBLE CAUSE
•  Open circuit in wiring between cooling fan relay No.2 terminal B and PCM terminal 28
•  Short to power in wiring between cooling fan relay No.2 terminal B and PCM terminal 28
•  Short to ground in wiring between cooling fan relay No.2 terminal B and PCM terminal 28
•  Open circuit in wiring between cooling fan relay No.2 terminal D and ignition switch
•  Damaged cooling fan relay No.2
•  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 P1474 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 LOW SPEED FAN CONTROL (LFC) CIRCUIT FOR INTERMITTENT FAILURE
•  Rerun KOEO, KOER self test and Continuous Memory DTCs.
•  Is DTC P1474 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.2.
•  Turn the ignition switch to the ON position.
•  Measure VPWR circuit voltage at cooling fan relay No.2 harness connector terminal D.
•  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 LFC CIRCUIT CYCLING
•  Turn the ignition switch to the ON position.
•  Connect a non-powered test lamp between VPWR circuit and the LFC circuit at cooling fan relay No.2 harness connector terminal B to D.
•  Access Output Test Mode LFC PID on the M-MDS.
•  While observing test lamp, command the LFC PID on and off.
•  Does the test lamp turned on and off when the cooling fan relay No.2 output is commanded on and off?
Yes
Replace cooling fan relay No.2, then go to Step 12.
No
Go to the next step.
7
CHECK LFC CIRCUIT FOR SHORT TO POWER IN HARNESS
•  Disconnect PCM.
•  Turn the ignition switch to the ON position.
•  Measure voltage between cooling fan relay No.2 terminal B 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 LFC CIRCUIT FOR SHORT TO GROUND HARNESS
•  Disconnect M-MDS to DLC-2.
•  Measure resistance between cooling fan relay No.2 terminal B 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 LFC CIRCUIT
•  Measure the resistance of the LFC circuit between the PCM terminal 28 and cooling fan relay No.2 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 LFC 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 (LOW) 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 LFC PID on the M-MDS.
•  Command LFC 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):
―  Shake wiggle and bend the LFC circuit between PCM and cooling fan relay No.2.
―  Shake wiggle and bend the VPWR circuit to the cooling fan relay No.2
―  Lightly tap on the cooling fan relay No.2 to simulate road shock
•  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 LFC CIRCUIT FOR SHORT TO GROUND
•  Turn the ignition switch to the ON position.
•  Command LFC 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 LFC circuit short to ground):
―  Shake wiggle and bend the LFC circuit between PCM and cooling fan relay No.2.
―  Lightly tap on the cooling fan relay No.2 to simulate road shock
•  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.
(See INTERMITTENT CONCERN TROUBLESHOOTING[AJ (3.0L Duratec)].)
12
VERIFY TROUBLESHOOTING OF DTC P1474 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.
(See PCM REMOVAL/INSTALLATION[AJ (3.0L Duratec)].)
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.