DTC P0506

Idle speed control system RPM lower than expected

DETECTION CONDITION

The actual idle speed is lower than expected by 100 rpm for 14 s , when the brake pedal is depressed (brake switch is on) and steering wheel is held straight ahead (PSP switch is off).
NOTE:
- If the atmospheric pressure is less than 72.3 kPa {542 mmHg, 21.3 inHg} or intake air temperature is below -10°C {14°F} , the PCM cancels diagnosis of P0506.

Diagnostic support note

This is a continuous monitor (CCM).
The MIL illuminates if the PCM detects the above malfunction conditions in two consecutive drive cycles or in one drive cycle while the DTC for the same malfunction has been stored in the PCM.
PENDING CODE is available if the PCM detects the above malfunction condition during the first drive cycle.
FREEZE FRAME DATA (Mode 2/Mode 12) is available.
The DTC is stored in the PCM memory.

POSSIBLE CAUSE

A/C relay control circuit malfunction
Electronic throttle control system malfunction
Purge solenoid valve malfunction
Air cleaner element clogged
Air intake passage clogged
Low engine compression (over capacity of blow-by gas)
Generator malfunction
PCM malfunction

DIAGNOSTIC PROCEDURE

STEP	INSPECTION		ACTION
1	VERIFY FREEZE FRAME DATA (MODE 12) HAS BEEN RECORDED Has the FREEZE FRAME DATA (Mode 12) been recorded?	Yes	Go to the next step.
1		No	Record the FREEZE FRAME DATA (Mode 12) on the repair order, then go to the next step.
2	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.
2		No	Go to the next step.
3	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. Are any DTCs present?	Yes	Go to the applicable DTC troubleshooting. (See DTC TABLE ).
3		No	Go to the next step.
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 ELECTRONIC THROTTLE CONTROL SYSTEM Turn the ignition switch off. Inspect the following parts: APP sensor (See ACCELERATOR PEDAL POSITION (APP) SENSOR INSPECTION ). TP sensor (See THROTTLE POSITION (TP) SENSOR INSPECTION ). Is there any malfunction?	Yes	Replace the malfunctioning parts according to the inspection results, then go to Step 11. (See ACCELERATOR PEDAL REMOVAL/INSTALLATION ). (See INTAKE-AIR SYSTEM REMOVAL/INSTALLATION ).
5		No	Go to the next step.
6	INSPECT PURGE SOLENOID VALVE Inspect the purge solenoid valve. (See PURGE SOLENOID VALVE INSPECTION ). Is there any malfunction?	Yes	Replace the purge solenoid valve, then go to Step 11. (See PURGE SOLENOID VALVE REMOVAL/INSTALLATION ).
6		No	Go to the next step.
7	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 11. (See INTAKE-AIR SYSTEM REMOVAL/INSTALLATION ).
7		No	Go to the next step.
8	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 11.
8		No	Go to the next step.
9	INSPECT ENGINE COMPRESSION Inspect the engine compression. (See COMPRESSION INSPECTION ). Is there any malfunction?	Yes	Perform the engine overhaul for repairs, then go to Step 11.
9		No	Go to the next step.
10	INSPECT GENERATOR Inspect the generator. (See GENERATOR INSPECTION [LF] .) Is there any malfunction?	Yes	Replace the generator, then go to the next step. (See GENERATOR REMOVAL/INSTALLATION [LF] ).
10		No	Go to the next step.
11	VERIFY TROUBLESHOOTING OF DTC P0506 COMPLETED Make sure to reconnect all disconnected connectors. Start the engine. Clear the DTC from the PCM memory using the M-MDS. Depress the brake pedal for 14 s or more. Is the PENDING CODE for this DTC present?	Yes	Replace the PCM, then go to the next step. (See PCM REMOVAL/INSTALLATION ).
11		No	Go to the next step.
12	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 ).
12		No	DTC troubleshooting completed.