Intake Air System: Diagnosis Honda CR-V II

DTC Troubleshooting

DIAGNOSTIC TROUBLE CODE (DTC) LIST

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1. Reset the ECM/PCM (see «HOW TO RESET THE ECM/PCM»(ref-171385-S07999163522005020300000) ).
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 IMRC valve position sensor and at the ECM/PCM.
3. Turn the ignition switch OFF.
4. Disconnect the IMRC valve position sensor 3P connector.
5. Turn the ignition switch ON (II).
6. Measure voltage between 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 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 IMRC valve position sensor (see «IMRC Valve Position Sensor Replacement»(ref-171389-S12515151892005021600000) ).
9. Measure resistance between IMRC valve position sensor 3P connector terminals No. 1 and No. 2. Is there about 9.5 k-ohm at room temperature? YES - Go to step 10. NO - Replace the IMRC valve position sensor (see «IMRC Valve Position Sensor Replacement»(ref-171389-S12515151892005021600000) ).
10. Disconnect ECM/PCM connector A (31P).
11. At the wire harness side, check for continuity between 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 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 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, then recheck (see «ECM/PCM UPDATING AND SUBSTITUTION FOR TESTING»(ref-171385-S32387647222005020300000) ). If the symptom/indication goes away with a known-good ECM/PCM, replace the original ECM/PCM. NO - Repair open in the wire between the ECM/PCM (A8) and the 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 IMRC valve position sensor. NO - Update the ECM/PCM if it does not have the latest software, or substitute a known-good ECM/PCM, then recheck (see «ECM/PCM UPDATING AND SUBSTITUTION FOR TESTING»(ref-171385-S32387647222005020300000) ). If the symptom/indication goes away with a known-good ECM/PCM, replace the original ECM/PCM.

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1. Reset the ECM/PCM (see «HOW TO RESET THE ECM/PCM»(ref-171385-S07999163522005020300000) ).
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 IMRC valve position sensor and at the ECM/PCM.
3. Turn the ignition switch OFF.
4. Disconnect the IMRC valve position sensor 3P connector.
5. Turn the ignition switch ON (II).
6. At the wire harness side, measure voltage between IMRC valve position sensor 3P connector terminals No. 1 and No. 3. Is there about 5 V? YES - Replace the IMRC valve position sensor (see «IMRC Valve Position Sensor Replacement»(ref-171389-S12515151892005021600000) ). 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 IMRC valve position sensor. NO - Update the ECM/PCM if it does not have the latest software, or substitute a known-good ECM/PCM, then recheck (see «ECM/PCM UPDATING AND SUBSTITUTION FOR TESTING»(ref-171385-S32387647222005020300000) ). If the symptom/indication goes away with a known-good ECM/PCM, replace the original ECM/PCM.

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 IF THE MIL (MALFUNCTION INDICATOR LAMP) HAS COME ON ).

1. With the engine off, check the throttle cable movement. The cable should move without binding or sticking. If the cable operates 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, and adjust it (see «Throttle Cable Adjustment»(ref-171389-S28836583072005020300000) ), then 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 or fully opened position, replace the throttle body. If the throttle valve and shaft are OK, go to step 3.
3. Connect the scan tool or the HDS to the data link connector (DLC).
4. Turn the ignition switch ON (II).
5. Check the throttle position with the scan tool or the HDS. The reading 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, the throttle body is OK. If the throttle position is not correct, check for poor connections or loose terminals at the TP sensor and the ECM/PCM. If the connections and terminals are OK, replace the throttle body.

Intake Air Bypass Control Thermal Valve Test

Special Tools Required

Vacuum pump/gauge, 0-30 in.Hg A973X-041-XXXXX

Scheme 300

1. Start the engine, and let it idle. NOTE: The engine coolant temperature must be below 149°F (65°C).
2. Remove the vacuum hose (A) from the intake air duct, and connect a vacuum pump 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 at 3,000 RPM with no 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 301

1. Remove the clamp (A), the nut (B), and the bolts (C).
2. Remove the air cleaner (D).
3. Install in the reverse order of removal.

Scheme 302

1. Remove the PCV hose (A). Open the air cleaner housing cover (B).
2. Remove the air cleaner (C) from the air cleaner housing (D).
3. Install in the reverse order of removal.

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1. Remove the throttle linkage cover plug (A).
2. Check cable free play at the throttle linkage. Cable free play (B) should be 10-12 mm (3/8-1/2 in.).
3. If the free play is not within spec (10-12 mm, 3/8-1/2 in.), remove the throttle linkage cover (A).
4. Loosen the locknut (A), turn the adjusting nut (B) until the free play (C) is as specified, then retighten the locknut.
5. 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.

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1. Remove the throttle linkage cover (A).
2. Fully open the throttle valve, then remove the throttle cable (A) from the throttle link (B).
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 at 3,000 RPM with no 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. Turn the adjusting nut (A) so that its free play is 0 mm.
9. Remove the cable from the cable bracket (B). Set the adjusting nut on the other side of cable bracket, then 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.

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

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1. Remove the intake manifold (see «REMOVAL»(ref-171634-S16753421762005021100000) ).
2. Disconnect the vacuum hose (A).
3. Remove the bolts (B).
4. Remove the IMRC actuator assembly (C). NOTE: When installing the IMRC actuator, make sure the bearing (D) is in place. Make sure the IMRC assembly does not interfere with the intake manifold (E). When installing the IMRC actuator, replace the new O-rings (F).
5. Install the IMRC actuator assembly (A) so that the hole (B) is visible.
6. Turn the IMRC actuator assembly (A), and align the bolt holes. NOTE: When turning the IMRC actuator assembly, make sure the stop (B) fits into the groove (C).