DTC P0506

Idle speed control system RPM lower than expected

DETECTION CONDITION

• Actual idle speed is lower than expected by 100 rpm for 14 s, when brake pedal is depressed (brake switch is on) and steering wheel is held straight ahead (power steering pressure (PSP) switch is off).

NOTE:

• If atmospheric pressure is less than 72.3 kPa {542 mmHg, 21.3inHg} 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 is available.

• The DTC is stored in the PCM memory.

POSSIBLE CAUSE

• Electronic throttle control system 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

STEP

INSPECTION

ACTION

1

• Has FREEZE FRAME DATA been recorded?

Yes

Go to the next step.

No

Record the FREEZE FRAME DATA on the repair order, then go to the next step.

2

• Verify related Service Bulletins and/or on-line repair information availability.

• Is any related repair information available?

Yes

Perform repair or diagnosis according to the available repair information.

• If the vehicle is not repaired, go to the next step.

No

Go to the next step.

3

• Turn the ignition switch off, then to the ON position (Engine off).

• Verify PENDING CODE or stored DTCs using the M-MDS.

• Are other DTCs present?

Yes

Repair the applicable DTCs.

(See DTC TABLE [LF].)

No

Go to the next step.

4

• Turn the fan switch off.

• Is the 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 9.

(See NO.24 A/C IS ALWAYS ON/A/C COMPRESSOR RUNS CONTINUOUSLY [LF].)

No

Go to the next step.

5

• Inspect the purge solenoid valve.

  (See PURGE SOLENOID VALVE INSPECTION [LF].)

• Is purge solenoid valve normal?

Yes

Go to the next step.

No

Replace the purge solenoid valve, then go to Step 9.

(SeePURGE SOLENOID VALVE REMOVAL/INSTALLATION [LF].)

6

• Remove the air cleaner element with the engine running.

• Is the engine speed increased?

Yes

Replace the air cleaner element, then go to Step 9.

(See INTAKE-AIR SYSTEM REMOVAL/INSTALLATION [LF].)

No

Go to the next step.

7

• Inspect the engine compression.

  (See COMPRESSION INSPECTION [LF].)

• Is the engine compression normal?

Yes

Go to the next step.

No

Overhaul the engine, then go to Step 9.

8

• Inspect the generator.

  (See GENERATOR INSPECTION [LF].)

• Is the generator normal?

Yes

Go to the next step.

No

Repair or replace the related part, then go to the next step.

9

• 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 [LF].)

No

Go to the next step.

10

• Perform “AFTER REPAIR PROCEDURE”.

  (See AFTER REPAIR PROCEDURE [LF].)

• Is any DTC present?

Yes

Go to the applicable DTC inspection.

(See DTC TABLE [LF].)

No

Troubleshooting completed.