Intake Air System Acura RSX I

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DTC Troubleshooting

DTC INDEX

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1. Reset the ECM/PCM (see «ECM/PCM RESET (2002-2004 MODELS)»(/acura/rsx/i-2001-2004/remont/auxiliary-emission-control-systems/#fuel-system-emissions-systems__ecmpcm-reset-2002-2004-models) ).
2. Turn the ignition switch ON (II). Is DTC P0661 indicated? YES - Go to step 3. NO - Intermittent failure, system is OK at this time. Check for poor connections or loose terminals at the IMT (IMRC) valve position sensor and the ECM/ PCM.
3. Turn the ignition switch OFF.
4. Disconnect the IMT (IMRC) valve position sensor 3P connector.
5. Turn the ignition switch ON (II).
6. Measure voltage between IMT (IMRC) valve position sensor 3P connector terminals No. 1 and No. 3. Is there about 5 V? YES - Go to step 7. NO - Go to step 14 .
7. Turn the ignition switch OFF.
8. At the sensor side, measure resistance between IMT (IMRC) valve position sensor 3P connector terminals No. 2 and No. 3. Is there about 3.2 kohm at room temperature? YES - Go to step 9. NO - Replace the IMT (IMRC) valve position sensor (see «IMT (IMRC) VALVE POSITION SENSOR REPLACEMENT»(/acura/rsx/i-2001-2004/remont/testing-diagnostics/#intake-air-system) ).
9. Measure resistance between IMT (IMRC) valve position sensor 3P connector terminals No. 1 and No. 2. Is there about 9.5 kohm at room temperature? YES - Go to step 10. NO - Replace the IMT (IMRC) valve position sensor (see «IMT (IMRC) VALVE POSITION SENSOR REPLACEMENT»(/acura/rsx/i-2001-2004/remont/testing-diagnostics/#intake-air-system) ).
10. Disconnect ECM/PCM connector A (31P).
11. At the wire harness side, check for continuity between IMT (IMRC) valve position sensor 3P connector terminal No. 2 and body ground. Is there continuity? YES - Repair short in the wire between the ECM/ PCM (A8) and the IMT (IMRC) valve position sensor. NO - Go to step 12.
12. Connect ECM/PCM connector terminal A8 to body ground with a jumper wire.
13. At the wire harness side, check for continuity between IMT (IMRC) valve position sensor 3P connector terminal No. 2 and body ground. Is there continuity? YES - Update the ECM/PCM if it does not have the latest software, or substitute a known-good ECM/ PCM (see «HOW TO UPDATE THE ECM/PCM»(/acura/rsx/i-2001-2004/remont/auxiliary-emission-control-systems/#fuel-system-emissions-systems__how-to-update-the-ecmpcm) ), then recheck. If the symptom/indication goes away with a known-good ECM/PCM, replace the original ECM/PCM (see «ECM/PCM REPLACEMENT»(/acura/rsx/i-2001-2004/remont/testing-diagnostics/#pgm-fi-system) ). NO - Repair open in the wire between the ECM/ PCM (A8) and the IMT (IMRC) valve position sensor.
14. Measure voltage between ECM/PCM connector terminals A11 and A21. Is there about 5 V? YES - Repair open in the wire between the ECM/ PCM (A21) and the IMT (IMRC) valve position sensor. NO - Update the ECM/PCM if it does not have the latest software, or substitute a known-good ECM/ PCM (see «HOW TO UPDATE THE ECM/PCM»(/acura/rsx/i-2001-2004/remont/auxiliary-emission-control-systems/#fuel-system-emissions-systems__how-to-update-the-ecmpcm) ), then recheck. If the symptom/indication goes away with a known-good ECM/PCM, replace the original ECM/PCM (see «ECM/PCM REPLACEMENT»(/acura/rsx/i-2001-2004/remont/testing-diagnostics/#pgm-fi-system) ).

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1. Reset the ECM/PCM (see «ECM/PCM RESET (2002-2004 MODELS)»(/acura/rsx/i-2001-2004/remont/auxiliary-emission-control-systems/#fuel-system-emissions-systems__ecmpcm-reset-2002-2004-models) ).
2. Turn the ignition switch ON (II). Is DTC P0661 indicated? YES - Go to step 3. NO - Intermittent failure, system is OK at this time. Check for poor connections or loose terminals at the IMT (IMRC) valve position sensor and the ECM/ PCM.
3. Turn the ignition switch OFF.
4. Disconnect the IMT (IMRC) valve position sensor 3P connector.
5. Turn the ignition switch ON (II).
6. Measure voltage between IMT (IMRC) valve position sensor 3P connector terminals No. 1 and No. 3. Is there about 5 V? YES - Go to step 7. NO - Go to step 15 .
7. Turn the ignition switch OFF.
8. At the sensor side, measure resistance between IMT (IMRC) valve position sensor 3P connector terminals No. 2 and No. 3. Is there about 3.2 kohm, at room temperature? YES - Go to step 9. NO - Go to step 16 .
9. Measure resistance between IMT (IMRC) valve position sensor 3P connector terminals No. 1 and No. 2. Is there about 9.5 kohm at room temperature? YES - Go to step 10. NO - Go to step 16 .
10. Jump the SCS line with the HDS.
11. Disconnect ECM/PCM connector A (31P).
12. At the wire harness side, check for continuity between IMT (IMRC) valve position sensor 3P connector terminal No. 2 and body ground. Is there continuity? YES - Repair short in the wire between the ECM/ PCM (B22) and the IMT (IMRC) valve position sensor, then go to step 17 . NO - Go to step 13.
13. Connect ECM/PCM connector terminal B22 to body ground with a jumper wire.
14. At the wire harness side, check for continuity between IMT (IMRC) valve position sensor 3P connector terminal No. 2 and body ground. Is there continuity? YES - Go to step 22 . NO - Repair open in the wire between the ECM/ PCM (B22) and the IMT (IMRC) valve position sensor, then go to step 17 .
15. Measure voltage between ECM/PCM connector terminals A21 and A24. Is there about 5 V? YES - Repair open in the wire between the ECM/ PCM (A21) and the IMT (IMRC) valve position sensor, then go to step 17 . NO - Go to step 22 .
16. Replace the IMT (IMRC) valve position sensor (see «IMT (IMRC) VALVE POSITION SENSOR REPLACEMENT»(/acura/rsx/i-2001-2004/remont/testing-diagnostics/#intake-air-system) ).
17. Reconnect all connectors.
18. Turn the ignition switch ON (II).
19. Reset the ECM/PCM with the HDS.
20. Do the ECM/PCM idle learn procedure (see «ECM/PCM IDLE LEARN PROCEDURE»(/acura/rsx/i-2001-2004/remont/testing-diagnostics/#idle-control-system) ).
21. Check for Temporary DTCs or DTCs with the HDS. Are any Temporary DTCs or DTCs indicated? YES - If DTC P0661 is indicated, check for poor connections or loose terminals at the IMT (IMRC) valve position sensor 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 - Troubleshooting is complete.
22. Update the ECM/PCM if it does not have the latest software, or substitute a known-good ECM/PCM (see «HOW TO UPDATE THE ECM/PCM»(/acura/rsx/i-2001-2004/remont/auxiliary-emission-control-systems/#fuel-system-emissions-systems__how-to-update-the-ecmpcm) ).
23. Check for Temporary DTCs or DTCs with the HDS. Are any Temporary DTCs or DTCs indicated? YES - If DTC P0661 is indicated, check for poor connections or loose terminals at the IMT (IMRC) valve position sensor 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 - If the ECM/PCM was updated, troubleshooting is complete. If the ECM/PCM was substituted, replace the original ECM/PCM (see «ECM/PCM REPLACEMENT»(/acura/rsx/i-2001-2004/remont/testing-diagnostics/#pgm-fi-system) ).

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1. Reset the ECM/PCM (see «ECM/PCM RESET (2002-2004 MODELS)»(/acura/rsx/i-2001-2004/remont/auxiliary-emission-control-systems/#fuel-system-emissions-systems__ecmpcm-reset-2002-2004-models) ).
2. Turn the ignition switch ON (II). Is DTC P0662 indicated? YES - Go to step 3. NO - Intermittent failure, system is OK at this time. Check for poor connections or loose terminals at the IMT (IMRC) valve position sensor and the ECM/ PCM.
3. Turn the ignition switch OFF.
4. Disconnect the IMT (IMRC) valve position sensor 3P connector.
5. Turn the ignition switch ON (II).
6. At the wire harness side, measure voltage between IMT (IMRC) valve position sensor 3P connector terminals No. 1 and No. 3. Is there about 5 V? YES - Replace the IMT (IMRC) valve position sensor (see «IMT (IMRC) VALVE POSITION SENSOR REPLACEMENT»(/acura/rsx/i-2001-2004/remont/testing-diagnostics/#intake-air-system) ). NO - Go to step 7.
7. Measure voltage between ECM/PCM connector terminals A11 and A21. Is there about 5 V? YES - Repair open in the wire between the ECM/ PCM (A11) and the IMT (IMRC) valve position sensor. NO - Update the ECM/PCM if it does not have the latest software, or substitute a known-good ECM/ PCM (see «HOW TO UPDATE THE ECM/PCM»(/acura/rsx/i-2001-2004/remont/auxiliary-emission-control-systems/#fuel-system-emissions-systems__how-to-update-the-ecmpcm) ), then recheck. If the symptom/indication goes away with a known-good ECM/PCM, replace the original ECM/PCM (see «ECM/PCM REPLACEMENT»(/acura/rsx/i-2001-2004/remont/testing-diagnostics/#pgm-fi-system) ).

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1. Reset the ECM/PCM (see «ECM/PCM RESET (2002-2004 MODELS)»(/acura/rsx/i-2001-2004/remont/auxiliary-emission-control-systems/#fuel-system-emissions-systems__ecmpcm-reset-2002-2004-models) ).
2. Turn the ignition switch ON (II). Is DTC P0662 indicated? YES - Go to step 3. NO - Intermittent failure, system is OK at this time. Check for poor connections or loose terminals at the IMT (IMRC) valve position sensor and the ECM/ PCM.
3. Turn the ignition switch OFF.
4. Disconnect the IMT (IMRC) valve position sensor 3P connector.
5. Turn the ignition switch ON (II).
6. At the wire harness side, measure voltage between IMT (IMRC) valve position sensor 3P connector terminals No. 1 and No. 3. Is there about 5 V? YES - Go to step 8 . NO - Go to step 7.
7. Measure voltage between ECM/PCM connector terminals A21 and A24. Is there about 5 V? YES - Repair open in the wire between the ECM/ PCM (A24) and the IMT (IMRC) valve position sensor, then go to step 10 . NO - Go to step 15 .
8. Turn the ignition switch OFF.
9. Replace the IMT (IMRC) valve position sensor (see «IMT (IMRC) VALVE POSITION SENSOR REPLACEMENT»(/acura/rsx/i-2001-2004/remont/testing-diagnostics/#intake-air-system) ).
10. Reconnect all connectors.
11. Turn the ignition switch ON (II).
12. Reset the ECM/PCM with the HDS.
13. Do the ECM/PCM idle learn procedure (see «ECM/PCM IDLE LEARN PROCEDURE»(/acura/rsx/i-2001-2004/remont/testing-diagnostics/#idle-control-system) ).
14. Check for Temporary DTCs or DTCs with the HDS. Are any Temporary DTCs or DTCs indicated? YES - If DTC P0662 is indicated, check for poor connections or loose terminals at the IMT (IMRC) valve position sensor 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 - Troubleshooting is complete.
15. Update the ECM/PCM if it does not have the latest software, or substitute a known-good ECM/PCM (see «HOW TO UPDATE THE ECM/PCM»(/acura/rsx/i-2001-2004/remont/auxiliary-emission-control-systems/#fuel-system-emissions-systems__how-to-update-the-ecmpcm) ).
16. Check for Temporary DTCs or DTCs with the HDS. Are any Temporary DTCs or DTCs indicated? YES - If DTC P0662 is indicated, check for poor connections or loose terminals at the IMT (IMRC) valve position sensor 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 - If the ECM/PCM was updated, troubleshooting is complete. If the ECM/PCM was substituted, replace the original ECM/PCM (see «ECM/PCM REPLACEMENT»(/acura/rsx/i-2001-2004/remont/testing-diagnostics/#pgm-fi-system) ).

DTC P1077: IMT (IMRC) System Malfunction (Low RPM) Stuck Short (2002-2004 models)

Special Tools Required

Vacuum pump/gauge, 0-30 in.Hg, Snap-on YA4000A or equivalent, commercially available

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1. Reset the ECM/PCM (see «ECM/PCM RESET (2002-2004 MODELS)»(/acura/rsx/i-2001-2004/remont/auxiliary-emission-control-systems/#fuel-system-emissions-systems__ecmpcm-reset-2002-2004-models) ).
2. Start the engine. Hold the engine speed at 3,000 RPM without load (in Park or neutral) until the radiator fan comes on. Is DTC P1077 indicated? YES - Go to step 3. NO - Intermittent failure, system is OK at this time. Check for poor connections or loose terminals at the intake manifold tuning (IMT) (intake manifold runner control (IMRC)) solenoid valve and the ECM/ PCM.
3. Disconnect the vacuum hose (A) from the intake manifold tuning (IMT) (intake manifold runner control (IMRC)) actuator (B), and connect the vacuum pump/gauge, 0-30 in.Hg, to the hose. Is there vacuum? YES - Go to step 11 . NO - Go to step 4.
4. Check the vacuum hose between the IMT (IMRC) actuator and the IMT (IMRC) solenoid valve. Is the vacuum hose OK? YES - Go to step 5. NO - Repair the blockage or vacuum leak between the IMT (IMRC) actuator and the IMT (IMRC) solenoid valve.
5. Disconnect the lower vacuum hose (A) from the IMT (IMRC) solenoid valve (B), and connect the vacuum pump/gauge, 0-30 in.Hg, to the hose. Is there vacuum? YES - Go to step 6. NO - Repair the blockage or vacuum leak between the intake manifold and the IMT (IMRC) solenoid valve.
6. Reconnect the lower vacuum hose to the IMT (IMRC) solenoid valve, and connect the vacuum pump/gauge, 0-30 in.Hg, to the vacuum hose (A).
7. Disconnect the IMT (IMRC) solenoid valve 2P connector. Is there vacuum? YES - Go to step 8. NO - Replace the IMT (IMRC) solenoid valve.
8. Turn the ignition switch OFF.
9. Disconnect ECM/PCM connector B (24P).
10. Check for continuity between IMT (IMRC) solenoid valve 2P connector terminal No. 2 and body ground. Is there continuity? YES - Repair short in the wire between the ECM/ PCM (B22) and the IMT (IMRC) solenoid valve. NO - Update the ECM/PCM if it does not have the latest software, or substitute a known-good ECM/ PCM (see «HOW TO UPDATE THE ECM/PCM»(/acura/rsx/i-2001-2004/remont/auxiliary-emission-control-systems/#fuel-system-emissions-systems__how-to-update-the-ecmpcm) ), then recheck. If the symptom/indication goes away with a known-good ECM/PCM, replace the original ECM/PCM (see «ECM/PCM REPLACEMENT»(/acura/rsx/i-2001-2004/remont/testing-diagnostics/#pgm-fi-system) ).
11. Turn the ignition switch OFF.
12. Connect the vacuum pump/gauge, 0-30 in.Hg, to the IMT (IMRC) actuator (A), then apply vacuum. YES - Go to step 13. NO - Replace the IMT (IMRC) valve assembly (see «IMT (IMRC) VALVE POSITION SENSOR REPLACEMENT»(/acura/rsx/i-2001-2004/remont/testing-diagnostics/#intake-air-system) ).
13. Disconnect the IMT (IMRC) valve position sensor 3P connector.
14. At the sensor side, measure resistance between IMT (IMRC) valve position sensor 3P connector terminals No. 2 and No. 3 while applying vacuum to the IMT (IMRC) actuator. Is there about 9.5 kohm, at room temperature? YES - Update the ECM/PCM if it does not have the latest software, or substitute a known-good ECM/ PCM (see «HOW TO UPDATE THE ECM/PCM»(/acura/rsx/i-2001-2004/remont/auxiliary-emission-control-systems/#fuel-system-emissions-systems__how-to-update-the-ecmpcm) ), then recheck. If the symptom/indication goes away with a known-good ECM/PCM, replace the original ECM/PCM (see «ECM/PCM REPLACEMENT»(/acura/rsx/i-2001-2004/remont/testing-diagnostics/#pgm-fi-system) ). NO - Replace the IMT (IMRC) valve assembly (see «IMT (IMRC) VALVE POSITION SENSOR REPLACEMENT»(/acura/rsx/i-2001-2004/remont/testing-diagnostics/#intake-air-system) ).

DTC PI077: IMT (IMRC) System Malfunction (Low RPM) Stuck Short (2005-2006 models)

Special Tools Required

Vacuum pump/gauge, 0-30 in.Hg, Snap-on YA4000A or equivalent, commercially available

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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. Do the IMT (IMRC) TEST in the INSPECTION MENU with the HDS. Is the result OK? YES - Intermittent failure, system is OK at this time. Check for poor connections or loose terminals at the intake manifold tuning (IMT) (intake manifold runner control (IMRC)) solenoid valve and the ECM/ PCM. NO - Go to step 3.
3. Turn the ignition switch OFF.
4. Check the vacuum hose and the hose connectors between the IMT (IMRC) actuator and the IMT (IMRC) solenoid valve. Are the vacuum hose and the hose connectors OK? YES - Go to step 5. NO - Repair the blockage or vacuum leak between the IMT (IMRC) actuator and the IMT (IMRC) solenoid valve, then go to step 27 .
5. Disconnect the vacuum hose (A) from the IMT (IMRC) actuator (B), and connect the vacuum pump/gauge, 0-30 in.Hg, to the hose.
6. Start the engine.
7. Measure the vacuum. Is there vacuum? YES - Go to step 8. NO - Go to step 13 .
8. Turn the ignition switch OFF.
9. Reconnect the vacuum hose to the IMT (IMRC) actuator.
10. Disconnect the vacuum hose (A) from the IMT (IMRC) solenoid valve (B), and connect the vacuum pump/gauge, 0-30 in.Hg, to the hose. Does the IMT (IMRC) actuator hold vacuum? YES - Go to step 11. NO - Replace the IMT (IMRC) valve (see «IMT (IMRC) VALVE POSITION SENSOR REPLACEMENT»(/acura/rsx/i-2001-2004/remont/testing-diagnostics/#intake-air-system) ), then go to step 27 .
11. Do the IMT (IMRC) TEST in the INSPECTION MENU with the HDS.
12. Apply 28 kPa (8.27 in.Hg, 210 mmHg) of vacuum to the hose. Does the reading on the HDS change? YES - Go to step 34 . NO - Replace the IMT (IMRC) valve (see «IMT (IMRC) VALVE POSITION SENSOR REPLACEMENT»(/acura/rsx/i-2001-2004/remont/testing-diagnostics/#intake-air-system) ), then go to step 27 .
13. Turn the ignition switch OFF.
14. Connect the vacuum hose to the IMT (IMRC) actuator.
15. Disconnect the lower vacuum hose (A) from the IMT (IMRC) solenoid valve (B), and connect the vacuum pump/gauge, 0-30 in.Hg, to the hose.
16. Start the engine.
17. Measure the vacuum. Is there vacuum? YES - Go to step 20 . NO - Go to step 18.
18. Turn the ignition switch OFF.
19. Check the vacuum hose and the hose connectors between the intake manifold and the IMT (IMRC) solenoid valve. Are the vacuum hose and the hose connectors OK? YES - Replace the intake manifold, K20Z1 engine (see «EXPLODED VIEW - K20A2, K20Z1 ENGINES»(/acura/rsx/i-2001-2004/remont/exhaust/#intake-manifold-and-exhaust-system) ), K20A3 engine (see «INTAKE MANIFOLD REMOVAL AND INSTALLATION»(/acura/rsx/i-2001-2004/remont/exhaust/#intake-manifold-and-exhaust-system) ), then go to step 27 . NO - Repair the blockage or vacuum leak between the intake manifold and the IMT (IMRC) solenoid valve, then go to step 27 .
20. Turn the ignition switch OFF.
21. Disconnect the IMT (IMRC) solenoid valve 2P connector.
22. Check for continuity between IMT (IMRC) solenoid valve 2P connector terminal No. 2 and body ground. Is there continuity? YES - Go to step 23. NO - Replace the IMT (IMRC) solenoid valve (see «IMT (IMRC) VALVE POSITION SENSOR REPLACEMENT»(/acura/rsx/i-2001-2004/remont/testing-diagnostics/#intake-air-system) ), then go to step 27 .
23. Turn the ignition switch OFF.
24. Jump the SCS line with the HDS.
25. Disconnect ECM/PCM connector A (31P).
26. Check for continuity between IMT (IMRC) solenoid valve 2P connector terminal No. 2 and body ground. Is there continuity? YES - Repair short in the wire between the IMT (IMRC) solenoid valve and the ECM/PCM (A11), then go to step 27. NO - Go to step 34 .
27. Reconnect all connectors.
28. Turn the ignition switch ON (II).
29. Reset the ECM/PCM with the HDS.
30. Do the ECM/PCM idle learn procedure (see «ECM/PCM IDLE LEARN PROCEDURE»(/acura/rsx/i-2001-2004/remont/testing-diagnostics/#idle-control-system) ).
31. Do the IMT (IMRC) TEST in the INSPECTION MENU with the HDS.
32. Check for Temporary DTCs or DTCs with the HDS. Are any Temporary DTCs or DTCs indicated? YES - If DTC P1077 is indicated, check for poor connections or loose terminals at the IMT (IMRC) solenoid valve 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 33.
33. Monitor the OBD STATUS for DTC P1077 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 IMT (IMRC) solenoid valve and the ECM/PCM, then go to step 1 . If the screen indicates NOT COMPLETED, go to step 30 and recheck.
34. Update the ECM/PCM if it does not have the latest software, or substitute a known-good ECM/PCM (see «HOW TO UPDATE THE ECM/PCM»(/acura/rsx/i-2001-2004/remont/auxiliary-emission-control-systems/#fuel-system-emissions-systems__how-to-update-the-ecmpcm) ).
35. Check for Temporary DTCs or DTCs with the HDS. Are any Temporary DTCs or DTCs indicated? YES - If DTC P1077 is indicated, check for poor connections or loose terminals at the IMT (IMRC) solenoid valve 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 - If the ECM/PCM was updated, troubleshooting is complete. If the ECM/PCM was substituted, replace the original ECM/PCM (see «ECM/PCM REPLACEMENT»(/acura/rsx/i-2001-2004/remont/testing-diagnostics/#pgm-fi-system) ).

DTC P1078: IMT (IMRC) System Malfunction (High RPM) Stuck Long (2002-2004 models)

Special Tools Required

Vacuum pump/gauge, 0-30 in.Hg, Snap-on YA4000A or equivalent, commercially available

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1. Reset the ECM/PCM (see «ECM/PCM RESET (2002-2004 MODELS)»(/acura/rsx/i-2001-2004/remont/auxiliary-emission-control-systems/#fuel-system-emissions-systems__ecmpcm-reset-2002-2004-models) ).
2. Start the engine. Hold the engine speed at 3,000 RPM without load (in Park or neutral) until the radiator fan comes on.
3. Raise the engine speed to 5,000 RPM. Is DTC P1078 indicated? YES - Go to step 4. NO - Intermittent failure, system is OK at this time. Check for poor connections or loose terminals at the intake manifold tuning (IMT) (intake manifold runner control (IMRC)) solenoid valve and the ECM/PCM.
4. Disconnect the vacuum hose (A) from the intake manifold tuning (IMT) (intake manifold runner control (IMRC)) actuator (B), and connect the vacuum pump/gauge, 0-30 in.Hg, to the hose.
5. Raise the engine speed to 5,000 RPM. Is there vacuum? YES - Go to step 6. NO - Go to step 15 .
6. Turn the ignition switch OFF.
7. Disconnect the IMT (IMRC) solenoid valve 2P connector.
8. Start the engine.
9. Raise the engine speed to 5,000 RPM, then measure voltage between IMT (IMRC) solenoid valve 2P connector terminals No. 1 and No. 2. Is there battery voltage? YES - Replace the IMT (IMRC) solenoid valve. NO - Go to step 10.
10. Measure voltage between IMT (IMRC) solenoid valve 2P connector terminal No. 1 and body ground. Is there battery voltage? YES - Go to step 11. NO - Check the No. 4ACG (10 A) fuse in the underdash fuse/relay box. If the fuse OK, repair open in the wire between the IMT (IMRC) solenoid valve and the No. 4 ACG (10 A) fuse.
11. Turn the ignition switch OFF.
12. Disconnect ECM/PCM connector B (24P).
13. Connect IMT (IMRC) solenoid valve 2P connector terminal No. 2 to body ground with a jumper wire.
14. Check for continuity between ECM/PCM connector terminal B22 and body ground. Is there continuity? YES - Update the ECM/PCM if it does not have the latest software, or substitute a known-good ECM/ PCM (see «ECM/PCM UPDATING AND SUBSTITUTION FOR TESTING»(/acura/rsx/i-2001-2004/remont/auxiliary-emission-control-systems/#fuel-system-emissions-systems__ecmpcm-updating-and-substitution-for-testing) ), then recheck. If the symptom/indication goes away with a known-good ECM/PCM, replace the original ECM/PCM (see «ECM/PCM REPLACEMENT»(/acura/rsx/i-2001-2004/remont/testing-diagnostics/#pgm-fi-system) ). NO - Repair open in the wire between the ECM/ PCM (B22) and the IMT (IMRC) solenoid valve.
15. Turn the ignition switch OFF.
16. Connect the vacuum pump/gauge, 0-30 in.Hg, to the IMT (IMRC) actuator (A), then apply vacuum. Does the IMT (IMRC) actuator hold vacuum? YES - Go to step 17. NO - Replace the IMT (IMRC) valve assembly (see «IMT (IMRC) VALVE POSITION SENSOR REPLACEMENT»(/acura/rsx/i-2001-2004/remont/testing-diagnostics/#intake-air-system) ).
17. Disconnect the IMT (IMRC) valve position sensor 3P connector.
18. At the sensor side, measure resistance between IMT (IMRC) valve position sensor 3P connector terminals No. 2 and No. 3. Is there about 3.2 kohm at room temperature? YES - Update the ECM/PCM if it does not have the latest software, or substitute a known-good ECM/ PCM (see «HOW TO UPDATE THE ECM/PCM»(/acura/rsx/i-2001-2004/remont/auxiliary-emission-control-systems/#fuel-system-emissions-systems__how-to-update-the-ecmpcm) ), then recheck. If the symptom/indication goes away with a known-good ECM/PCM, replace the original ECM/PCM (see «ECM/PCM REPLACEMENT»(/acura/rsx/i-2001-2004/remont/testing-diagnostics/#pgm-fi-system) ). NO - Replace the IMT (IMRC) valve assembly (see «IMT (IMRC) VALVE POSITION SENSOR REPLACEMENT»(/acura/rsx/i-2001-2004/remont/testing-diagnostics/#intake-air-system) ).

DTC P1078: IMT (IMRC) System Malfunction (High RPM) Stuck Long (2005-2006 models)

Special Tools Required

Vacuum pump/gauge, 0-30 in.Hg, Snap-on YA4000A or equivalent, commercially available

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1. Reset the ECM/PCM with the HDS.
2. 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.
3. Do the IMT (IMRC) TEST in the INSPECTION MENU with the HDS. Is the result OK? YES - Intermittent failure, systems OK at this time. Check for poor connections or loose terminals at the intake manifold tuning (IMT) (intake manifold runner control (IMRC)) solenoid valve and the ECM/ PCM. NO - Go to step 4.
4. Turn the ignition switch OFF.
5. Disconnect the vacuum hose (A) from the IMT (IMRC) actuator (B), and connect the vacuum pump/gauge, 0-30 in. Hg, to the hose.
6. Start the engine.
7. Do the IMT (IMRC) TEST in the INSPECTION MENU with the HDS. Is about 101 kPa (29.9 in.Hg, 760 mmHg), or about 2.9 V at sea level indicated with in 5 seconds? YES - Replace the IMT (IMRC) solenoid valve (see «IMT (IMRC) VALVE POSITION SENSOR REPLACEMENT»(/acura/rsx/i-2001-2004/remont/testing-diagnostics/#intake-air-system) ), then go to step 21 . NO - Go to step 8.
8. Apply vacuum using the vacuum pump/gauge, 0-30 in.Hg, to the hose (A).
9. Do the IMT (IMRC) TEST in the INSPECTION MENU with the HDS, Does the IMT (IMRC) solenoid valve hold vacuum? YES - Check for a restricted air cleaner element (see «AIR CLEANER REMOVAL/INSTALLATION»(/acura/rsx/i-2001-2004/remont/testing-diagnostics/#intake-air-system) ). If necessary, replace the IMT (IMRC) solenoid valve (see «IMT (IMRC) VALVE POSITION SENSOR REPLACEMENT»(/acura/rsx/i-2001-2004/remont/testing-diagnostics/#intake-air-system) ), then go to step 21 . NO - Go to step 10.
10. Turn the ignition switch OFF.
11. Disconnect the IMT (IMRC) solenoid valve 2P connector.
12. Turn the ignition switch ON (II).
13. Measure voltage between IMT (IMRC) solenoid valve 2P connector terminal No. 1 and body ground. Is there battery voltage? YES - Go to step 14. NO - Repair open in the wire between the IMT (IMRC) solenoid valve and the No. 4 ACG (10 A) fuse in the underdash fuse/relay box, then go to step 20 .
14. Turn the ignition switch OFF.
15. Jump the SCS line with the HDS.
16. Disconnect ECM/PCM connector A (31P).
17. Connect IMT (IMRC) solenoid valve 2P connector terminal No. 2 to body ground with a jumper wire.
18. Check for continuity between ECM/PCM connector terminal A11 and body ground. Is there continuity? YES - Go to step 19. NO - Repair open in the wire between the ECM/ PCM (A11) and the IMT (IMRC) solenoid valve, then go to step 20 .
19. At the sensor side, measure resistance between IMT (IMRC) solenoid valve 2P connector terminals No. 1 and No. 2. Is there about 45°. at room temperature? YES - Go to step 26 . NO - Replace the IMT (IMRC) solenoid valve (see «IMT (IMRC) VALVE POSITION SENSOR REPLACEMENT»(/acura/rsx/i-2001-2004/remont/testing-diagnostics/#intake-air-system) ), then go to step 20.
20. Reconnect all connectors.
21. Turn the ignition switch ON (II).
22. Reset the ECM/PCM with the HDS.
23. Do the ECM/PCM idle learn procedure (see «ECM/PCM IDLE LEARN PROCEDURE»(/acura/rsx/i-2001-2004/remont/testing-diagnostics/#idle-control-system) ).
24. Check for Temporary DTCs or DTCs with the HDS. Are any Temporary DTCs or DTCs indicated? YES - If DTC P1078 is indicated, check for poor connections or loose terminals at the IMT (IMRC) solenoid valve 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 25.
25. Monitor the OBD STATUS for DTC P1078 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 IMT (IMRC) solenoid valve and the ECM/PCM, then go to step 1 . If the screen indicates NOT COMPLETED, go to step 23 and recheck.
26. Update the ECM/PCM if it does not have the latest software, or substitute a known-good ECM/PCM (see «HOW TO UPDATE THE ECM/PCM»(/acura/rsx/i-2001-2004/remont/auxiliary-emission-control-systems/#fuel-system-emissions-systems__how-to-update-the-ecmpcm) ).
27. Check for Temporary DTCs or DTCs with the HDS. Are any Temporary DTCs or DTCs indicated? YES - If DTC P1078 is indicated, check for poor connections or loose terminals at the IMT (IMRC) solenoid valve 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 - If the ECM/PCM was updated, troubleshooting is complete. If the ECM/PCM was substituted, replace the original ECM/PCM (see «ECM/PCM REPLACEMENT»(/acura/rsx/i-2001-2004/remont/testing-diagnostics/#pgm-fi-system) ).

Throttle Body Test

Note. Do not adjust the throttle stop screw. It is preset at the factory. If the malfunction indicator lamp (MIL) has been reported on, check for diagnostic trouble codes (DTCs) (see ECM/PCM RESET (2002-2004 MODELS) ).

1. With the engine off, check the throttle cable operation. The cable should move without binding or sticking. If the cable operated OK, go to step 2. If the cable binds or sticks, check it and its routing. If the cable is faulty, reroute it or replace it then adjust it, K20A2/K20Z1 engines (see «THROTTLE CABLE ADJUSTMENT»(/acura/rsx/i-2001-2004/remont/testing-diagnostics/#intake-air-system) ), K20A3 engine (see «THROTTLE CABLE ADJUSTMENT»(/acura/rsx/i-2001-2004/remont/testing-diagnostics/#intake-air-system) ). When the cable is properly adjusted, go to step 2.
2. Operate the throttle lever by hand to see if the throttle valve and/or shaft are too loose or too tight. If there is excessive play in the throttle valve shaft, or any binding in the throttle valve at the fully closed position, replace the throttle body. If the throttle valve and shaft are OK, go to step 3.
3. Connect the HDS or a scan tool to the data link connector (DLC).
4. Turn the ignition switch ON (II).
5. Check the throttle position with the HDS or a scan tool. There should be about 10% or 0.5 V when the throttle is fully closed and about 90% or 4.5 V when the throttle is fully opened. If the throttle position is correct, check the throttle body for carbon deposits, and clean it if needed. If the throttle position is not correct, replace the throttle body.

Throttle Body Cleaning

1. Check for damage to the air cleaner.
2. Remove the throttle body, K20A2/K20Z1 engines (see «THROTTLE BODY REMOVAL/INSTALLATION»(/acura/rsx/i-2001-2004/remont/testing-diagnostics/#intake-air-system__throttle-body-removalinstallation) ), K20A3 engine (see «K20A3 ENGINE»(/acura/rsx/i-2001-2004/remont/testing-diagnostics/#intake-air-system) ).
3. Clean off any carbon from the throttle valve and inside of the throttle body with throttle plate and induction cleaner.
4. Install the throttle body, K20A2/K20Z1 engines (see «THROTTLE BODY REMOVAL/INSTALLATION»(/acura/rsx/i-2001-2004/remont/testing-diagnostics/#intake-air-system__throttle-body-removalinstallation) ), K20A3 engine (see «K20A3 ENGINE»(/acura/rsx/i-2001-2004/remont/testing-diagnostics/#intake-air-system) ).
5. Do the ECM/PCM idle learn procedure, 2002-2004 models (see «ECM/PCM IDLE LEARN PROCEDURE»(/acura/rsx/i-2001-2004/remont/testing-diagnostics/#idle-control-system) ), 2005-2006 models (see «ECM/PCM IDLE LEARN PROCEDURE»(/acura/rsx/i-2001-2004/remont/testing-diagnostics/#idle-control-system) ).

Throttle Position Sensor Signal Inspection

Note. This procedure is to inspect the abnormalities of the throttle position sensor full closed position. Other failures than full closed position will store a DTC, therefore the procedure to inspect them are not included in this procedure. Check for Temporary DTCs or DTCs with the HDS before this procedure. If there are any DTCs indicated, troubleshoot them first, then do this procedure. Press the accelerator pedal several times, and check the operation. If it does not operate properly check the accelerator pedal, the throttle cable, and the throttle linkage individually. If you fined a problem in one of them, replace the parts that caused the problem.

Scheme 460

1. Connect the HDS to the data link connector (DLC) (A) located under the driver's side of the dashboard.
2. Turn the ignition switch ON (II).
3. Make sure the accelerator pedal is not pressed and check the REL TP SENSOR in the DATA LIST with the HDS. If it is below 10%, the throttle position sensor is OK. If it is above 10%, adjust the throttle cable, K20A2/K20Z1 engines (see «THROTTLE CABLE ADJUSTMENT»(/acura/rsx/i-2001-2004/remont/testing-diagnostics/#intake-air-system) ), K20A3 engine (see «THROTTLE CABLE ADJUSTMENT»(/acura/rsx/i-2001-2004/remont/testing-diagnostics/#intake-air-system) ), then go to step 4.
4. Make sure the accelerator pedal is not pressed and check the REL TP SENSOR in the DATA LIST with the HDS. If it is below 10%, the throttle position sensor is OK. If it is above 10%, update the ECM/PCM if it does not have the latest software, or substitute a known-good ECM/PCM (see «HOW TO UPDATE THE ECM/PCM»(/acura/rsx/i-2001-2004/remont/auxiliary-emission-control-systems/#fuel-system-emissions-systems__how-to-update-the-ecmpcm) ), then go to step 5.
5. Make sure the accelerator pedal is not pressed and check the REL TP SENSOR in the DATA LIST with the HDS. If it is below 10%, the throttle position sensor is OK. If it is above 10%, replace the throttle body assembly, K20A2/K20Z1 engines (see «THROTTLE BODY REMOVAL/INSTALLATION»(/acura/rsx/i-2001-2004/remont/testing-diagnostics/#intake-air-system__throttle-body-removalinstallation) ), K20A3 engine (see «K20A3 ENGINE»(/acura/rsx/i-2001-2004/remont/testing-diagnostics/#intake-air-system) ), then go to step 1 .

Intake Air Bypass Control Thermal Valve Test

Special Tools Required

Vacuum pump/gauge, 0-30 in.Hg, Snap-on YA4000A or equivalent, commercially available

Scheme 461

1. Start the engine, and let it idle. NOTE: Engine coolant temperature must be below 149 °F(65 °C).
2. Remove the vacuum hose (A) from the intake air duct, and connect the vacuum pump/gauge, 0-30 in.Hg, to the hose.
3. Raise and lower the engine speed, and make sure the vacuum gauge reading changes as the engine speed changes. If the vacuum reading does not change, check for these problems: Misrouted, leaking, broken, or clogged intake air bypass control system vacuum lines. A cracked or damage intake air bypass control thermal valve.
4. 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. Raise and lower the engine speed, and make sure the vacuum gauge reading does not change as the RPM changes. If the vacuum reading changes, check for these problems: Misrouted, leaking, broken, or clogged intake air bypass control system vacuum lines. A cracked or damaged intake air bypass control thermal valve.

Scheme 462

1. Remove the intake manifold cover, K20A3 engine (see step 1 on «REMOVAL - K20A3 ENGINE»(/acura/rsx/i-2001-2004/remont/exhaust/#intake-manifold-and-exhaust-system) ), K20A2/K20Z1 engines (see step 2 on «REMOVAL - K20A2, K20Z1 ENGINES»(/acura/rsx/i-2001-2004/remont/exhaust/#intake-manifold-and-exhaust-system) ).
2. Disconnect the hoses (A).
3. Remove the intake air bypass control thermal valve (B).
4. Install the valve in the reverse order of removal. NOTE: Position the valve angle as shown.

Scheme 463

1. Remove the clamp (A) and the nuts (B).
2. Remove the air cleaner (C).
3. Install the parts in the reverse order of removal.

Scheme 464

1. Remove the clamp (A) and the screws (B), then open the air cleaner housing cover (C).
2. Remove the air cleaner (D) from the air cleaner housing (E).
3. Check the air cleaner element for damage or clogging. If it is damaged or clogged, replace it. NOTE: Do not use compressed air to clean the air cleaner element.
4. Install the parts in the reverse order of removal.

Scheme 465

1. Check cable free play at the throttle linkage. Cable deflection (A) should be 10-12 mm (3/8-1/2 in).
2. If deflection (A) is not within spec (10-12 mm, 3/8-1/2 in.) loosen the locknut (B), turn the adjusting nut (C) until the deflection is as specified, then retighten the locknut.
3. With the cable properly adjusted, check the throttle valve to be sure it opens fully when you push the accelerator pedal to the floor. Also check the throttle valve to be sure it returns to the idle position whenever you release the accelerator pedal.

Scheme 466

1. Remove the inspection hole plug (A).
2. Check cable free play at the throttle linkage. Cable deflection (B) should be 10-12 mm (3/8-1/2 in.).
3. If deflection (B) is not within spec (10-12 mm, 3/8-1/2 in.), remove the throttle linkage cover (C), loosen the locknut (D), turn the adjusting nut (E) until the deflection is as specified, then retighten the locknut.
4. With the cable properly adjusted, check the throttle valve to be sure it opens fully when you push the accelerator pedal to the floor. Also check the throttle valve to be sure it returns to the idle position whenever you release the accelerator pedal.

Scheme 467

Scheme 468

Scheme 469

Scheme 470

Scheme 471

1. Remove the throttle linkage cover (A) (K20A3 engine only).
2. Fully open the throttle valve, then remove the throttle cable (A) from the throttle link (B). K20A2/K20Z1 engines K20A3 engine
3. Remove the cable housing (C) from the cable bracket (D).
4. Remove the throttle cable (A) from the accelerator pedal (B).
5. Install in the reverse order of removal.
6. After installing, 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.
7. Hold the cable, removing all slack from it.
8. Set the locknut on the cable bracket (A). Turn the adjusting nut (B) so that its free play is 0 mm.
9. Remove the cable from the throttle bracket (A). Reset the adjusting nut (B), and tighten the locknut (C).
10. With the cable properly adjusted, check the throttle valve to be sure it opens fully when you push the accelerator pedal to the floor. Also check the throttle valve to be sure it returns to the idle position whenever you release the accelerator pedal.

Throttle Body Removal/Installation

Note. Do not adjust the throttle stop screw. After reassembly, adjust the cruise control cable (see CRUISE CONTROL ACTUATOR CABLE ADJUSTMENT ) and the throttle cable (see THROTTLE CABLE REMOVAL/INSTALLATION ). The throttle position (TP) sensor is not removable.

Scheme 472

Note. Do not adjust the throttle stop screw. After reassembly, adjust the cruise control cable (see CRUISE CONTROL ACTUATOR CABLE ADJUSTMENT ) and the throttle cable (see THROTTLE CABLE REMOVAL/INSTALLATION ). The throttle position (TP) sensor is not removable.

Scheme 473

Scheme 474

Scheme 475

Scheme 476

1. Remove the two screws (A) and the IMT (IMRC) position sensor (B).
2. Install the sensor with a new O-ring (C), and make sure the projection (D) inside the IMT (IMRC) valve matches up with the groove (E) in the sensor.

Scheme 477

1. Remove the intake manifold (see «INTAKE MANIFOLD REMOVAL AND INSTALLATION»(/acura/rsx/i-2001-2004/remont/exhaust/#intake-manifold-and-exhaust-system) ).
2. Disconnect the vacuum hose (A), then remove the bolts (B), and remove the IMT (IMRC) valve assembly (C).
3. Install the parts in the reverse order of removal with a new O-rings (D). NOTE: Make sure the bearing (E) is secured into place.

See also:
• ECM/PCM RESET (2002-2004 MODELS)
• HOW TO UPDATE THE ECM/PCM
• ECM/PCM REPLACEMENT
• ECM/PCM IDLE LEARN PROCEDURE
• EXPLODED VIEW - K20A2, K20Z1 ENGINES
• ECM/PCM UPDATING AND SUBSTITUTION FOR TESTING
• CRUISE CONTROL ACTUATOR CABLE ADJUSTMENT
• DTC P0661
• DTC P1077
• DTC P1078
• THROTTLE BODY REMOVAL/INSTALLATION