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 MCM connector E (22P) and the battery module 6P connector.
7. Check for continuity between MCM connector terminal E12 and body ground.
Is there continuity?
YES-Repair short in the wire between the battery module and the MCM (E12).
NO-Go to step 8.
8. At the battery module side, check for continuity between body ground and battery module 6P connector terminal No. 33.
Is there continuity?
YES-Replace the battery module.
NO-Go to step 9
9. Reconnect MCM connector E (22P).
10. Turn the ignition switch ON (II).
11. Measure voltage between battery module 6P connector terminals No. 3 and No. 4.
Is there about 5 V?
YES-Replace the battery module.
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.