DTC P1506[AJ (3.0L Duratec)]


id0102a4826100

DTC P1506

IAC overspeed error

DETECTION CONDITION
•  This DTC is set when the PCM detects engine idle speed that is greater than the desired rpm.
POSSIBLE CAUSE
•  IAC solenoid valve malfunction
•  Air cleaner element clogged
•  Air intake passage clogged
•  A/C relay control circuit malfunction
•  Generator malfunction
•  Purge solenoid valve malfunction
•  Low engine compression (Over capacity of blow-by gas)
•  PCM malfunction

Diagnostic procedure

STEP

INSPECTION

ACTION

1
VERIFY FREEZE FRAME DATA HAS BEEN RECORDED
•  Has FREEZE FRAME DATA been recorded?
Yes
Go to next step.
No
Record FREEZE FRAME DATA on repair order, then go to next step.
2
VERIFY RELATED SERVICE INFORMATION AVAILABILITY
•  Check for related Service Information and/or on-line Service Information availability.
•  Is any related Service Information available?
Yes
Perform repair or diagnosis according to available Service Information.
•  If vehicle is not repaired, then go to next step.
No
Go to next step.
3
VERIFY RELATED PENDING OR STORED DTCS
•  Turn the ignition switch off, then ON (Engine OFF).
•  Verify pending code or stored DTCs using M-MDS.
•  Is other DTC present?
Yes
Repair applicable DTCs.
No
Go to next step.
4
INSPECT IAC SOLENOID VALVE MALFUNCTION
•  Perform IAC solenoid valve inspection.
•  Is IAC solenoid valve normal?
Yes
Go to next step.
No
Replace IAC solenoid valve, then go to Step 11.
5
INSPECT A/C MAGNET CLUTCH OPERATION
•  Turn blower motor switch off.
•  Is magnet clutch still on?
Yes
Refer to “A/C is always on or A/C compressor runs continuously.” of ENGINE SYMPTOM TROUBLESHOOTING, then go to Step 11.
No
Go to next step.
6
INSPECT PURGE SOLENOID VALVE MALFUNCTION
•  Perform purge solenoid valve inspection.
•  Is purge solenoid valve normal?
Yes
Go to next step.
No
Replace purge solenoid valve, then go to Step 11.
7
INSPECT AIR CLEANER ELEMENT
•  Remove air cleaner element with engine running.
•  Is engine speed increased?
Yes
Replace air cleaner element, then go to Step 11.
No
Go to next step.
8
INSPECT THROTTLE BODY PASSAGE
•  Is throttle body clogged?
Yes
Clean or replace throttle body passage, then go to Step 11.
No
Go to next step.
9
INSPECT ENGINE COMPRESSION
•  Inspect engine compression.
•  Is engine compression normal?
Yes
Go to next step.
No
Overhaul engine, then go to Step 11.
10
INSPECT GENERATOR
•  Perform generator inspection.
•  Is generator normal?
Yes
Go to next step.
No
Repair or replace related part, then go to next step.
11
VERIFY TROUBLESHOOTING OF DTC P1506 COMPLETED
•  Make sure to reconnect all disconnected connectors.
•  Start engine.
•  Clear DTC from PCM memory using M-MDS.
•  Is PENDING CODE for this DTC present?
Yes
Replace PCM, then go to next step.
No
Go to next step.
12
VERIFY AFTER REPAIR PROCEDURE
•  Perform "AFTER REPAIR PROCEDURE".
•  Is there any DTC present?
Yes
Go to applicable DTC inspection.
No
Troubleshooting completed.