DTC P0505

DTC P0505	Idle speed control system problem
DETECTION CONDITION	The PCM cannot control idle speed toward target idle speed while KOER self test. Diagnostic support note The MIL does not illuminate. FREEZE FRAME DATA (Mode 2/Mode 12) is not available. The DTC is not stored in the PCM memory.
POSSIBLE CAUSE	Drive-by-wire control system malfunction A/C relay control circuit malfunction Generator control circuit malfunction Air cleaner element clogged Air intake passage clogged Low engine compression (over capacity of blow-by gas) PCM malfunction

DIAGNOSTIC PROCEDURE

STEP	INSPECTION		ACTION
1	VERIFY RELATED SERVICE BULLETINS AVAILABILITY Verify related Service Bulletins availability. Is any related Service Bulletins available?	Yes	Perform the repair or diagnosis according to the available Service Bulletins. If the vehicle is not repaired, go to the next step.
1		No	Go to the next step.
2	VERIFY RELATED PENDING CODE AND STORED DTC Turn the ignition switch off then to the ON position (Engine off). Verify the PENDING CODE and stored DTC using the M-MDS. Is the DTC P0506, P0507, P0638, P2101, P2107, P2108, P2109, P2112 or P2119 also present?	Yes	Go to the applicable DTC troubleshooting. (See DTC TABLE ).
2		No	Go to the next step.
3	INSPECT ELECTRONIC THROTTLE CONTROL SYSTEM OPERATION Perform the Electronic Throttle Control System Inspection. (See ENGINE CONTROL SYSTEM OPERATION INSPECTION ). Does the electronic throttle control system work properly?	Yes	Go to the next step.
3		No	Repair or replace the malfunctioning part according to the inspection results, then go to Step 9.
4	INSPECT A/C MAGNETIC CLUTCH OPERATION NOTE: The following test should be performed for the A/C. Go to the next step for vehicles without A/C. 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 ).
4		No	Go to the next step.
5	INSPECT GENERATOR CONTROL CIRCUIT MALFUNCTION Apply the electrical load. Is the engine speed increased?	Yes	Go to the next step.
5		No	Repair or replace the wiring harness for a possible short to power supply in generator control circuit, then go to Step 9.
6	INSPECT AIR CLEANER ELEMENT Remove the air cleaner element with the engine running. Is the engine speed increased?	Yes	Clean or replace the air cleaner element, then go to Step 9. (See INTAKE-AIR SYSTEM REMOVAL/INSTALLATION ).
6		No	Go to the next step.
7	INSPECT THROTTLE BODY PASSAGE Visually inspect the throttle body passage. Is the throttle body passage clogged?	Yes	Clean or replace the throttle body passage, then go to Step 9.
7		No	Go to the next step.
8	INSPECT ENGINE COMPRESSION Inspect the engine compression. (See COMPRESSION INSPECTION ). Is there any malfunction?	Yes	Perform the engine overhaul for repairs, then go to the next step.
8		No	Go to the next step.
9	VERIFY TROUBLESHOOTING OF DTC P0505 COMPLETED Make sure to reconnect all disconnected connectors. Clear the DTC from the PCM memory using the M-MDS. Perform the KOER sell test. (See KOEO/KOER SELF TEST ). Is the same DTC present?	Yes	Replace the PCM, then go to the next step. (See PCM REMOVAL/INSTALLATION ).
9		No	Go to the next step.
10	VERIFY AFTER REPAIR PROCEDURE Perform the "AFTER REPAIR PROCEDURE". (See AFTER REPAIR PROCEDURE ). Are any DTCs present?	Yes	Go to the applicable DTC inspection. (See DTC TABLE ).
10		No	DTC troubleshooting completed.