Idle Control System: Diagnosis Acura RSX I facelift

DTC Troubleshooting

DTC INDEX

Note. Information marked with * 1 applies to K20A3 engine; * 2 applies to K20A2 engine. If DTC P1519 is stored at the same time as DTC P0505, troubleshooting DTC P1519 first, then recheck for DTC P0505.

Scheme 377

1. Start the engine. Hold the engine speed at 3,000 RPM without load (in Park or neutral) until the radiator fan comes on, then let it idle.
2. Check the engine speed at idle without load conditions: headlights, blower fan, rear defogger, radiator fan, and air conditioner off. Is the engine running at 650* 1 (700)* 2 +/-50 RPM? YES - Intermittent failure, system is OK at this time. NO - If the idle speed is less than 600* 1 (650)* 2 RPM, go to step 3; if it's 700* 1 (750)* 2 RPM or higher, go to step 4 .
3. Disconnect the idle air control (IAC) valve 3P connector. Does the engine speed increase or fluctuate? YES - Check the idle speed with a different load condition (electrical, A/C, gear position, P/S, etc.) (see «IDLE SPEED INSPECTION»(ref-218787-S10893819532006021000000) ). If it's out of specification, replace the IAC valve (see «THROTTLE BODY DISASSEMBLY/REASSEMBLY»(ref-218789-S10770291502006021000000) ). NO - Replace the IAC valve (see «THROTTLE BODY DISASSEMBLY/REASSEMBLY»(ref-218789-S10770291502006021000000) ).
4. Turn the ignition switch OFF.
5. Remove the air intake duct from the throttle body.
6. Start the engine, and let it idle.
7. Put your fingers on the lower port (A) in the throttle body. Does the engine speed drop below 700* 1 (750)* 2 RPM? YES - Check the idle speed with a different load condition (electrical, A/C, gear position, P/S, etc.) (see «IDLE SPEED INSPECTION»(ref-218787-S10893819532006021000000) ). If it's out of specification, replace the IAC valve (see «THROTTLE BODY DISASSEMBLY/REASSEMBLY»(ref-218789-S10770291502006021000000) ). NO - Check for vacuum leaks at these parts. PCV valve PCV hose EVAP canister purge valve Intake manifold Throttle body Brake booster hose Intake air bypass control thermal valve

Note. If DTC P0511 is stored at the same time as DTC P0506, troubleshoot DTC P0511 first, then recheck for DTC P0506. Information marked with * 1 applies to K20A3 engine; * 2 applies to K20A2 engine.

1. Start the engine. Hold the engine speed at 3,000 RPM without load (in Park or neutral) until the radiator fan comes on, then let it idle.
2. Check the engine speed at idle without load conditions: headlights, blower fan, rear defogger, radiator fan, and air conditioner off. Is the engine running at 650* 1 (700)* 2 +/-50 RPM? YES - Intermittent failure, system is OK at this time. NO - Go to step 3.
3. Turn the ignition switch OFF.
4. Disconnect the IAC valve 3P connector.
5. Start the engine, and let it idle.
6. Check the engine speed at idle without load conditions: headlights, blower fan, rear defogger, and air conditioner off. Does the engine speed increase or fluctuate? YES - Check the idle speed with a different load condition (electrical, A/C, gear position, P/S, etc.) (see «IDLE SPEED INSPECTION»(ref-218787-S10893819532006021000000) ). If it's out of specification, replace the IAC valve (see «THROTTLE BODY DISASSEMBLY/REASSEMBLY»(ref-218789-S10770291502006021000000) ). NO - Replace the IAC valve (see «THROTTLE BODY DISASSEMBLY/REASSEMBLY»(ref-218789-S10770291502006021000000) ).

1. Turn the ignition switch ON (II).
2. Clear the DTC with the HDS.
3. Start the engine. Hold the engine speed at 3,000 RPM without load (in Park or neutral) until the radiator fan comes on, then let it idle.
4. Check for these conditions in the DATA LIST with the HDS. Engine coolant temperature above 158°F(70°C) Intake air temperature above 32°F (0°C) Vehicle speed is 0 mph (0 km/h) ST FUEL TRIM between 0.69 and 1.47 FSS is CLOSED
5. Monitor the OBD STATUS for DTC P0506 in the DTCs MENU with the HDS. Does the screen indicate FAILED? YES - Go to step 6. NO - If the screen indicates PASSED, go to step 15 . If the screen indicates EXECUTING, let the engine idle until a result comes on. If the screen indicates OUT OF CONDITION, go to step 4 and recheck.
6. Remove the air intake duct from the throttle body.
7. Check for dirt, carbon, or damage in the throttle bore. Is there dirt, carbon, or damage in the throttle bore? YES - If there is dirt or carbon, clean the throttle body (see «THROTTLE BODY TEST»(ref-218789-S22596817412006021000000) ), and also check for damage at the air cleaner element (see «AIR CLEANER REMOVAL/INSTALLATION»(ref-218789-S18697254912006021000000) ), then go to step 9 . If there is damage in the throttle bore, go to step 8. NO - Check the A/C system or power steering system, then go to step 17 .
8. Replace the throttle body (see «THROTTLE BODY REMOVAL/INSTALLATION»(ref-218789-S28222118142006021000000) ).
9. Reset the ECM/PCM with the HDS.
10. Do the ECM/PCM idle learn procedure (see «ECM/PCM IDLE LEARN PROCEDURE»(ref-218787-S18900728242006021000000) ).
11. Start the engine. Hold the engine speed at 3,000 RPM without load (in Park or neutral) until the radiator fan comes on, then let it idle.
12. Check for these conditions in the DATA LIST with the HDS. Engine coolant temperature above 158°F(70°C) Intake air temperature above 32°F (0°C) Vehicle speed is 0 mph (0 km/h) ST FUEL TRIM between 0.69 and 1.47 FSS is CLOSED
13. Check for Temporary DTCs or DTCs with the HDS. Are any Temporary DTCs or DTCs indicated? YES - If DTC P0506 is indicated, go to step 1 and recheck. If any other Temporary DTCs or DTCs are indicated, go to the indicated DTC's troubleshooting. NO - Go to step 14.
14. Monitor the OBD STATUS for DTC P0506 in the DTCs MENU with the HDS. Does the screen indicate PASSED? YES - Troubleshooting is complete. NO - If the screen indicates FAILED, go to step 1 and recheck. If the screen indicates EXECUTING, let the engine idle until a result comes on. If the screen indicates OUT OF CONDITION, go to step 12 and recheck.
15. Remove the air intake duct from the throttle body.
16. Check for dirt, carbon, or damage in the throttle bore. Is there dirt, carbon, or damage in the throttle bore? YES - If there is dirt or carbon, clean the throttle body (see «THROTTLE BODY TEST»(ref-218789-S22596817412006021000000) ), and also check for damage at the air cleaner element (see «AIR CLEANER REMOVAL/INSTALLATION»(ref-218789-S18697254912006021000000) ), then go to step 9 . If there is damage in the throttle bore, go to step 8 . NO - Go to step 17.
17. Recheck with different load conditions (turn on the headlights, blower motor, rear window defogger and/or A/C, changing the gear position, etc.)
18. Monitor the OBD STATUS for DTC P0506 in the DTCs MENU with the HDS. Does the screen indicate PASSED? YES - Intermittent failure, system is OK at this time. NO - If the screen indicates FAILED, check the A/C system and/or power steering system, then go to step 1 and recheck. If the screen indicates EXECUTING, let the engine idle until a result comes on. If the screen indicates OUT OF CONDITION, go to step 17 and recheck.

Note. If DTC P0511 is stored at the same time as DTC P0507, troubleshoot DTC P0511 first; then recheck for DTC P0507. Information marked with * 1 applies to K20A3 engine; * 2 applies to K20A2 engine.

Scheme 378

1. Start the engine. Hold the engine speed at 3,000 RPM without load (in Park or neutral) until the radiator fan comes on, then let it idle.
2. Check the engine speed at idle without load conditions: headlights, blower fan, rear defogger, and air conditioner off. Is the engine running at 650* (700)* 2 2 +/-50 RPM? YES - Intermittent failure, system is OK at this time. NO - Go to step 3.
3. Turn the ignition switch OFF.
4. Remove the air cleaner from the throttle body (see «AIR CLEANER REMOVAL/INSTALLATION»(ref-218789-S18697254912006021000000) ).
5. Start the engine, and let it idle.
6. Put your fingers on the lower port (A) in the throttle body. Does the engine speed drop below 700* 1 (750)* 2 RPM? YES - Check the idle speed with a different load condition (electrical, A/C, gear position, P/S etc.) (see «IDLE SPEED INSPECTION»(ref-218787-S10893819532006021000000) ). If it's out of specification, replace the IAC valve (see «THROTTLE BODY DISASSEMBLY/REASSEMBLY»(ref-218789-S10770291502006021000000) ). NO - Check for vacuum leaks at these parts. PCV valve PCV hose EVAP canister purge valve Throttle body Intake manifold Brake booster hose Intake air bypass control thermal valve

1. Turn the ignition switch ON (II).
2. Clear the DTC with the HDS.
3. Start the engine, Hold the engine speed at 3,000 RPM without load (in Park or neutral) until the radiator fan comes on, then let it idle.
4. Monitor the OBD STATUS for DTC P0506 in the DTCs MENU with the HDS. Does the screen indicate FAILED ? YES - Go to step 5. NO - If the screen indicates PASSED, intermittent failure, system is OK at this time. If the screen indicates EXECUTING, let the engine idle until a result comes on. If the screen indicates OUT OF CONDITION, recheck with different load conditions (electrical, A/C, gear position, etc.), then go to step 3 .
5. Check for vacuum leaks at these parts: PCV valve PCV hose EVAP canister purge valve Throttle body Intake manifold Brake booster hose Intake air bypass control thermal valve Are there any leaks? YES - Repair or replace the leaking part(s), then go to step 6. NO - Go to step 6.
6. Turn the ignition switch ON (II).
7. Reset the ECM/PCM with the HDS.
8. Do the ECM/PCM idle learn procedure (see «ECM/PCM IDLE LEARN PROCEDURE»(ref-218787-S18900728242006021000000) ).
9. Start the engine. Hold the engine speed at 3,000 RPM without load (in Park or neutral) until the radiator fan comes on, then let it idle.
10. Check for Temporary DTCs or DTCs with the HDS. Are any Temporary DTCs or DTCs indicated? YES - If DTC P0507 is indicated, check for poor connections or loose terminals at the throttle body, and the ECM/PCM, then go to step 1 . If any other Temporary DTCs or DTCs are indicated, go to the indicated DTC's troubleshooting. NO - Go to step 11.
11. Monitor the OBD STATUS for DTC P0507 in the DTCs MENU with the HDS. Does the screen indicate PASSED? YES - Troubleshooting is complete. NO - If the screen indicates FAILED, check for poor connections or loose terminals at the throttle body, and the ECM/PCM, then go to step 1 . If the screen indicates EXECUTING, let the engine idle until a result comes on. If the screen indicates OUT OF CONDITION, recheck with different load conditions (electrical, A/C, gear position, etc.), then go to step 9 .

Idle Speed Inspection

Note. Leave the idle air control (IAC) valve connected. Before checking the idle speed, check these items: The malfunction indicator lamp (MIL) has not been reported on. Ignition timing Sparkplugs Air cleaner PCV system Pull the parking brake lever up. Start the engine, and make sure the headlights are off.

Scheme 379

Scheme 380

1. Disconnect the evaporative emission (EVAP) canister purge valve 2P connector.
2. 2002-2004 models: Connect a tachometer (A) to the test tachometer connector (B), or connect the HDS or a scan tool to the data link connector (DLC) (C) located under the driver's side of the dashboard. 2002-2004 models 2002-2006 models
3. 2005-2006 models: Connect the HDS to the data link connector (DLC) under the driver's side of the dashboard.
4. Start the engine. Hold the engine speed at 3,000 RPM without load (in Park or neutral) until the radiator fan comes on, then let it idle.
5. Check the idle speed without load conditions: headlights, blower fan, radiator fan, and air conditioner off. Idle speed should be: K20A2 engine: 700+/-50 RPM K20A3 engine: IDLE SPEED SPECIFICATION M/T 700+/-50 RPM A/T 700+/-50 RPM (in Park or neutral) K20Z1 engine: 800+/-50 RPM
6. Let the engine idle 1 minute with high electric load (A/C switch ON, temperature set to Max Cool, blower fan on High, rear window defogger ON, and head lights on high beam). Idle speed should be: K20A2 engine: 780+/-50 RPM K20A3 engine-2002-2004 models: IDLE SPEED SPECIFICATION M/T 720+/-50 RPM A/T 720+/-50 RPM (in Park or neutral) K20Z1 engine: 850+/-50 RPM K20A3 engine-2005-2006 models: IDLE SPEED SPECIFICATION M/T 700+/-50 RPM A/T 700+/-50 RPM (in Park or neutral) NOTE: If the idle speed is not within specification, do the ECM/PCM idle learn procedure, 2002-2004 models (see «ECM/PCM IDLE LEARN PROCEDURE»(ref-218787-S18900728242006021000000) ), 2005-2006 models (see «ECM/PCM IDLE LEARN PROCEDURE»(ref-218787-S18900728242006021000000) ). If the idle is still out of specification, go to the symptom troubleshooting.
7. Reconnect the EVAP canister purge valve 2P connector.

2002-2004 models

The idle learn procedure must be done so the ECM/PCM can learn the engine idle characteristics.

Do the idle learn procedure whenever you do any of these actions

1. Disconnect the battery.
2. Replace the ECM/PCM or disconnect its connector.
3. Replace or clean the throttle body.
4. Reset the ECM/PCM. NOTE: Erasing DTCs with the HDS does not require you to do the idle learn procedure.
5. Remove the No. 6 ECU (ECM/PCM) (15 A) fuse from the underhood fuse/relay box.
6. Remove the No. 19 battery (100 A) fuse from the underhood fuse/relay box.
7. Remove PGM-FI main relay 1 (FI MAIN).
8. Remove any of the wires from the underhood fuse/relay box
9. Disconnect any of the connectors from the underhood fuse/relay box.
10. Disconnect the connector between the engine compartment wire harness and ECM/PCM wire harness.
11. Disconnect the G2 terminal from the transmission housing.
12. Disconnect the G1 terminal from the body.
13. Disconnect the G101 terminal from the water passage.