DTC P151B:00 [PCM (SKYACTIV-G 2.5T)]

id0102s8889300

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 check engine light does not illuminate. • FREEZE FRAME DATA is not available. • Snapshot data is available. • DTC is stored in the PCM memory.
FAIL-SAFE FUNCTION	• Not applicable
POSSIBLE CAUSE	• A/C magnetic clutch malfunction • Drive-by-wire control system malfunction • Malfunction in injection amount measurement system (refer to DTC P0101:00) • Purge solenoid valve malfunction • Air cleaner element restricted • Throttle body passage blockage • Engine malfunction ? Insufficient engine compression • Generator control circuit malfunction • PCM malfunction
SYSTEM WIRING DIAGRAM	• Not applicable

Diagnostic Procedure

STEP	INSPECTION		ACTION
1	RECORD VEHICLE STATUS AT TIME OF DTC DETECTION TO UTILIZE WITH REPEATABILITY VERIFICATION Note • Recording can be facilitated using the screen capture function of the PC. • Record the snapshot data on the repair order.	—	Go to the next step.
2	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.
2		No	Go to the next step.
3	VERIFY RELATED PENDING CODE AND/OR DTC • Switch the ignition off, then ON (engine off). • Perform the Pending Trouble Code Access Procedure and DTC Reading Procedure. (See ON-BOARD DIAGNOSTIC TEST [PCM (SKYACTIV-G 2.5T)].) • Are any other PENDING CODEs and/or DTCs present?	Yes	Go to the applicable PENDING CODE or DTC inspection. (See DTC TABLE [PCM (SKYACTIV-G 2.5T)].)
3		No	Go to the next step.
4	INSPECT A/C MAGNETIC CLUTCH OPERATION • Turn the A/C 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 2.5T].)
4		No	Go to the next step.
5	INSPECT DRIVE-BY-WIRE CONTROL SYSTEM MALFUNCTION • Perform the Drive-by-wire Control System Inspection. (See ENGINE CONTROL SYSTEM OPERATION INSPECTION [SKYACTIV-G 2.5T].) • Is there any malfunction?	Yes	Repair or replace the malfunctioning part according to the inspection results, then go to Step 11.
5		No	Go to the next step.
6	INSPECT PURGE SOLENOID VALVE • Perform the Purge Control System Inspection. (See ENGINE CONTROL SYSTEM OPERATION INSPECTION [SKYACTIV-G 2.5T].) • Is there any malfunction?	Yes	Repair or replace the malfunctioning part according to the inspection results, then go to Step 11. (See PURGE SOLENOID VALVE REMOVAL/INSTALLATION [SKYACTIV-G 2.5T].)
6		No	Go to the next step.
7	INSPECT AIR CLEANER ELEMENT • Remove the air cleaner element with the engine is running. (See INTAKE-AIR SYSTEM REMOVAL/INSTALLATION [SKYACTIV-G 2.5T].) • Does the engine speed increase?	Yes	Clean or replace the air cleaner element, then go to Step 11. (See INTAKE-AIR SYSTEM REMOVAL/INSTALLATION [SKYACTIV-G 2.5T].)
7		No	Go to the next step.
8	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 11. (See INTAKE-AIR SYSTEM REMOVAL/INSTALLATION [SKYACTIV-G 2.5T].)
8		No	Go to the next step.
9	INSPECT ENGINE COMPRESSION • Inspect the engine compression. (See COMPRESSION INSPECTION [SKYACTIV-G 2.5T].) • Are compression pressures within specification?	Yes	Go to the next step.
9		No	Repair or replace the malfunctioning part according to the inspection results, then go to Step 11.
10	INSPECT GENERATOR CONTROL CIRCUIT FOR SHORT TO POWER SUPPLY • Apply the electrical load (such as blower fan, rear window defogger, or headlight). • Does the engine speed increase?	Yes	Go to the next step.
10		No	Repair or replace the malfunctioning part according to the inspection results, then go to the next step.
11	VERIFY DTC TROUBLESHOOTING COMPLETED • Always reconnect all disconnected connectors. • Clear the DTC from the PCM memory using the M-MDS. (See CLEARING DTC [PCM (SKYACTIV-G 2.5T)].) • Perform the KOER self test. (See KOEO/KOER SELF TEST [PCM (SKYACTIV-G 2.5T)].) • Is the same DTC present?	Yes	Repeat the inspection from Step 1. • If the malfunction recurs, replace the PCM. (See PCM REMOVAL/INSTALLATION [SKYACTIV-G 2.5T].) Go to the next step.
11		No	Go to the next step.
12	VERIFY AFTER REPAIR PROCEDURE • Perform the “AFTER REPAIR PROCEDURE”. (See AFTER REPAIR PROCEDURE [PCM (SKYACTIV-G 2.5T)].) • Are any DTCs present?	Yes	Go to the applicable DTC inspection. (See DTC TABLE [PCM (SKYACTIV-G 2.5T)].)
12		No	DTC troubleshooting completed.