IMT (IMRC) System Troubleshooting

1.Start the engine and allow it to idle.

2.Disconnect the vacuum hose (A) from IMT (IMRC) actuator (B), and connect the vacuum/ gauge (C) to the hose.

 

Is there vacuum?


YES - Go to 10.


NO - Go to 3.


3.Check the vacuum hose between the IMT (IMRC) actuator and IMT (IMRC) solenoid valve.

Is there vacuum hose OK?


YES - Go to 4.


NO - Repair the blockage or vacuum leak between the IMT (IMRC) actuator and IMT (IMRC) solenoid valve.n

4.Disconnect the lower vacuum hose (A) from IMT (IMRC) solenoid valve (B), and connect the vacuum/gauge (C) to the hose.

 

Is there vacuum?


YES - Go to 5.


NO - Repair the blockage or vacuum leak between the intake manifold and IMT (IMRC) solenoid valve.n


5.Reconnect the lower vacuum hose to the IMT (IMRC) solenoid valve, and connect the vacuum pump/ gauge to the vacuum hose (actuator side).

6.Disconnect the IMT (IMRC) solenoid valve 2P connector.

Is there vacuum?


YES - Go to 7.


NO - Replace the IMT (IMRC) solenoid valve.n

7.Turn the ignition switch OFF.

8.Jump the SCS line with the HDS.

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.n


NO - Update the ECM/PCM if it does not have the latest software, or substitute a known-good ECM/PCM, then recheck. If symptom/indication goes away with a known-good ECM/PCM, replace the original ECM/PCM.n


11.Raise engine speed to 5,000 rpm (min-1).

12.Check for vacuum.

Is there vacuum?


YES - Go to 13.


NO - Go to 23.


13.Turn the ignition switch OFF.

14.Disconnect the IMT (IMRC) solenoid valve 2P connector.

15.Start the engine.

16.Raise engie speed to 5,000 rpm (min-1), then measure voltage between IMT (IMRC) solenoid valve 2P connector terminal No. 1 and No. 2.

 

Is there battery voltage?


YES - Replace the IMT (IMRC) solenoid valve.n


NO - Go to 17.


17.Measure voltage between IMT (IMRC) solenoid valve 2P connector terminal No. 1 and body ground.

 

Is there battery voltage?


YES - Go to 18.


NO - Check the No. 4 ACG (10 A) fuse in the under-dash fuse/relay box. If the fuse OK, repair open in the wire between the IMT (IMRC) solenoid valve and No. 4 ACG (10 A) fuse.

18.Turn the ignition switch OFF.

19.Jump the SCS line with the HDS.

20.Disconnect ECM/PCM connector B (24P).

21.Connect IMT (IMRC) solenoid valve 2P connector terminal No. 2 to body ground with a jumper wire.

 

22.Check for continuity between ECM/PCM connector terminal A11 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. If symptom/indication goes away with a known-good ECM/PCM, replace the original ECM/PCM.n


NO - Repair open in the wire between the  ECM/ PCM (A11) and the IMT (IMRC) solenoid valve.n

23.Connect the vacuum/ gauge (A) to the IMT (IMRC) actuator (B), then apply vacuum.

 

Does the IMT (IMRC) actuator hold vacuum?


YES - Go to 24.


NO - Replace the IMT (IMRC) valve assembly.n


24.Install the cotter pin (A) to the IMT (IMRC) actuator shaft (B).

 


25.Apply vacuum to the IMT (IMRC) actuator, then check the cotter pin movement.

Does the cotter pin move?


YES - IMT (IMRC) system is OK.n


NO - Replace the IMT (IMRC) valve assembly.n