P1557
DTC P1557 (53): Battery Module Temperature Sensor 3 Signal Circuit Low Input1. Reset the MCM.
2. Turn the ignition switch ON (II).
Is DTC P1557 indicated?
YES - Go to step 3.
NO - Intermittent failure, system is OK at this time. Check for poor connections or loose terminals at the battery module and at the MCM.
3. Turn the ignition switch OFF.
4. Turn the battery module switch OFF.
5. Remove the IPU lid.
6. Disconnect the battery module 6P connector.
7. Turn the ignition switch ON (II).
8. Measure voltage between MCM connector terminals E12 and E13.
Is there more than 2.5 V?
YES - Replace the battery module.
NO - Go to step 9.
9. Turn the ignition switch OFF.
10. Disconnect MCM connector E (22P).
11. Check for continuity between body ground and MCM connector terminal E12.
Is there continuity?
YES - Repair short in the wire between the battery module and the MCM (E12).
NO - Update the MCM if it does not have the latest software, or substitute a known-good MCM, then recheck. If the symptom/indication goes away with a known-good MCM, replace the original MCM.