P1078
DTC P1078: IMT (IMRC) System Malfunction (High rpm) Stuck LongSpecial Tools Required
Vacuum Pump/Gauge, 0 - 30 in.Hg, Snap-on YA4000A or equivalent, commercially available
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 at 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 vacuum pump/gauge, 0 - 30 in.Hg, to the hose.
6. Apply vacuum using a vacuum pump/gauge, 0 - 30 in.Hg, to the hose (A).
7. 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. If necessary, replace the IMT (IMRC) solenoid valve, then go to step 18.
NO - Go to step 8.
8. Disconnect the IMT (IMRC) solenoid valve 2P connector.
9. Turn the ignition switch ON (II).
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 - Repair open in the wire between the IMT (IMRC) solenoid valve and the No.4 ACG (10 A) fuse in the under dash fuse/relay box, then go to step 17.
11. Turn the ignition switch OFF.
12. Jump the SCS line with the HDS.
13. Disconnect ECM/PCM connector A (31P).
14. Connect IMT (IMRC) solenoid valve 2P connector terminal No.2 to body ground with a jumper wire.
15. Check for continuity between ECM/PCM connector terminal A11 and body ground.
Is there continuity?
YES - Go to step 16.
NO - Repair open in the wire between the ECM/PCM (A11) and the IMT (IMRC) solenoid valve, then go to step 17.
16. At the sensor side, measure resistance between IMT (IMRC) solenoid valve 2P connector terminal No.1 and No.2.
Is there about 45 Ohm. at room temperature?
YES - Go to step 18.
NO - Replace the IMT (IMRC) solenoid valve, then go to step 17.
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.
21. 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 22.
22. 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 20 and recheck.
23. Update the ECM/PCM if it does not have the latest software, or substitute a known-good ECM/PCM.
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 - If the ECM/PCM was updated, troubleshooting is complete. If the ECM/PCM was substituted, replace the original ECM/PCM.