P1077
DTC P1077: IMRC System Malfunction (Low rpm)Special Tools Required
Vacuum pump/gauge, 0 - 30 in.Hg A973X-041-XXXXX
1. Reset the ECM/PCM.
2. Start the engine and hold it at 3,000 rpm with no 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 Runner Control (IMRC) solenoid Valve and at the ECM/PCM.
3. Disconnect the vacuum hose (A) from the Intake Manifold Runner Control (IMRC) actuator (B), and connect a vacuum pump to the hose.
Is there vacuum?
YES - Go to step 11.
NO - Go to step 4.
4. Check the vacuum hose between IMRC actuator and IMRC solenoid valve.
Is the vacuum hose OK?
YES - Go to step 5.
NO - Repair the blockage or vacuum leak between the IMRC actuator and IMRC solenoid valve.
5. Disconnect the lower vacuum hose (A) from the IMRC solenoid valve (B), and connect a vacuum pump to the hose.
Is there vacuum?
YES - Go to step 6.
NO - Repair the blockage or vacuum leak between the intake manifold and IMRC solenoid valve.
6. Reconnect the lower vacuum hose to the IMRC solenoid valve, and connect the vacuum pump to the vacuum hose (A).
7. Disconnect the IMRC solenoid valve 2P connector.
Is there vacuum?
YES - Go to step 8.
NO - Replace the IMRC solenoid valve 8.
9. Disconnect ECM/PCM connector B (24P).
10. Check for continuity between 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 IMRC solenoid valve.
NO - Update the ECM/PCM if it does not have the latest software, or substitute a known-good ECM/PCM, then recheck. If the symptom/indication goes away with a known-good ECM/PCM, replace the original ECM/PCM.
11. Turn the ignition switch OFF.
12. Connect the vacuum pump to the IMRC actuator (A), then apply vacuum.
Does the IMRC actuator hold vacuum?
YES - Go to step 13.
NO - Replace the IMRC valve assembly.
13. Disconnect the IMRC valve position sensor 3P connector.
14. At the sensor side, measure resistance between IMRC valve position sensor 3P connector terminals No.2 and No.3 while applying vacuum to the 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, then recheck. If the symptom/indication goes away with a known-good ECM/PCM, replace the original ECM/PCM.