DTC P151B:00 [SKYACTIV-G 2.0]

id0102h1889300

DTC P151B:00

IAC system problem
DETECTION CONDITION
•  The PCM cannot control the idle speed toward the target idle speed during the KOER self test.
Diagnostic support note
•  The MIL does not illuminate.
•  FREEZE FRAME DATA (Mode 2)/Snapshot data is not available.
•  The DTC is stored in the PCM memory.
FAIL-SAFE FUNCTION
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POSSIBLE CAUSE
•  Improper operation of drive-by-wire control system
•  Improper operation of air conditioner
•  Generator control circuit malfunction
•  Air cleaner element restricted
•  Throttle body passage blockage
•  Low engine compression (over capacity of blow-by gas)
•  PCM malfunction
SYSTEM WIRING DIAGRAM
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Diagnostic Procedure

STEP

INSPECTION

ACTION
1
VERIFY RELATED 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 the next step.
No
Go to the next step.
2
VERIFY RELATED PENDING CODE AND/OR DTC
•  Switch the ignition to off, then to ON (engine off).
•  Perform the Pending Trouble Code Access Procedure and DTC Reading Procedure.
•  Are any other PENDING CODEs and/or DTCs present?
Yes
Go to the applicable PENDING CODE or DTC inspection.
(See DTC TABLE [SKYACTIV-G 2.0].)
No
Go to the next step.
3
INSPECT DRIVE-BY-WIRE CONTROL SYSTEM OPERATION
•  Perform the throttle position (TP) sweep inspection.
•  Does the drive-by-wire control system work properly?
Yes
Go to the next step.
No
Repair or replace the malfunctioning part according to the inspection results, then go to Step 9.
4
INSPECT A/C MAGNETIC CLUTCH OPERATION
•  Turn the fan switch off.
•  Is the magnetic clutch still on?
Yes
Perform the symptom troubleshooting “NO.24 A/C IS ALWAYS ON OR A/C COMPRESSOR RUNS CONTINUOUSLY”.
(See NO.24 A/C IS ALWAYS ON OR A/C COMPRESSOR RUNS CONTINUOUSLY [SKYACTIV-G 2.0].)
No
Go to the next step.
5
INSPECT GENERATOR CONTROL CIRCUIT MALFUNCTION
•  Apply the electrical load.
•  Does the engine speed increase?
Yes
Go to the next step.
No
Repair or replace the generator control circuit for a possible short to power supply, then go to Step 9.
6
INSPECT AIR CLEANER ELEMENT
•  Remove the air cleaner element with the engine is running.
•  Does the engine speed increase?
Yes
Clean or replace the air cleaner element, then go to Step 9.
No
Go to the next step.
7
INSPECT THROTTLE BODY PASSAGE
•  Visually inspect the throttle body passage.
•  Is the throttle body passage dirty and/or restricted?
Yes
Clean or replace the throttle body passage, then go to Step 9.
(See INTAKE-AIR SYSTEM REMOVAL/INSTALLATION [SKYACTIV-G 2.0].)
No
Go to the next step.
8
INSPECT ENGINE COMPRESSION
•  Inspect the engine compression.
•  Are compression pressures within specification?
Specification:
•  Standard: 827 kPa {8.43 kgf/cm2, 120 psi} (300 rpm)
•  Minimum: 661 kPa {6.74 kgf/cm2, 95.9 psi} (300 rpm)
•  Maximum difference between cylinders: 140 kPa {1.43 kgf/cm2, 20.3 psi}
Note
•  Because the SKYACTIV-G 2.0 retards the intake valve closing timing, compression pressure is low.
Yes
Go to the next step.
No
Repair or replace the malfunctioning part according to the inspection results, then go to the next step.
9
VERIFY DTC TROUBLESHOOTING COMPLETED
•  Make sure to reconnect all disconnected connectors.
•  Clear the DTC from the PCM memory using the M-MDS.
•  Perform the KOER self test.
•  Is the same DTC present?
Yes
Repeat the inspection from Step 1.
•  If the malfunction recurs, replace the PCM.
Go to the next step.
No
Go to the next step.
10
VERIFY AFTER REPAIR PROCEDURE
•  Perform the “AFTER REPAIR PROCEDURE”.
•  Are any DTCs present?
Yes
Go to the applicable DTC inspection.
(See DTC TABLE [SKYACTIV-G 2.0].)
No
DTC troubleshooting completed.