P1633
DTC P1633 (55): ECM Signal Circuit Problem1. Reset the MCM.
2. Turn the ignition switch OFF.
3. Turn the ignition switch ON (II).
Is DTC P1633 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. Turn the battery module switch OFF.
6. Remove the IPU lid.
7. Disconnect MCM connector A (31P).
8. Disconnect the ECM connector A (31P).
9. Check for continuity between MCM connector terminal A19 and body ground.
Is there continuity?
YES - Repair short in the wire between ECM (A16) and the MCM (A19).
NO - Go to step 10.
10. Connect ECM connector terminal A16 to body ground with a jumper wire.
11. Check for continuity between MCM connector terminal A19 and body ground.
Is there continuity?
YES - Update the MCM and ECM if they do not have the latest software, or substitute a known good MCM and ECM, then recheck. If the symptom/indication goes away with a known good MCM and ECM, replace the original MCM and ECM.
NO - Repair open in the wire between the ECM (A16) and the MCM (A19).