Mode Signal Circuit 1 High Input

DTC 6 (P1647, P16B8): Mode Signal Circuit 1 High Input

NOTE: If DTCs 2, 4, and 6 are stored at the same time after the ECM is updated, do the troubleshooting for DTC 7.

1. Turn the ignition switch ON (II) and watch the MIL.
Does the MIL come on for the first 2 seconds?
YES-Go to step 2.
NO-Do the MIL circuit troubleshooting.
2. Reset the MCM.
3. Turn the ignition switch ON (II).
Is DTC 6 indicated?
YES-Go to step 4.
NO-Intermittent failure, system is OK at this time. Check for poor connections or loose terminals at the ECM and at the MCM.
4. Turn the ignition switch OFF.
5. Disconnect ECM connector D (16P).
6. Turn the ignition switch ON (II).





7. Measure voltage between ECM connector terminals D6 and B20.
Is there about 5 V?
YES-Substitute a known-good ECM, and recheck; 2000-2001 models, 2002-2005 models. If the symptom/indication goes away, replace the original ECM.
NO-Go to step 8.
8. Turn the ignition switch OFF.
9. Turn the battery module switch OFF.
10. Remove the IPU lid.
11. Turn the ignition switch ON (II).





12. Measure voltage between MCM connector terminals C12 and A24.
Is there about 5 V?
YES-Repair open in the wire between the MCM (C12) and the ECM (D6).
NO-Substitute a known-good MCM, turn the battery module switch ON, and recheck. If the symptom/indication goes away, replace the original MCM.