P1443
DTC P1443 (46): High Voltage Contactor/Bypass Contactor Stays Activated1. Reset the MCM.
2. Turn the ignition switch ON (II).
3. Turn the ignition switch OFF. Wait for 30 seconds.
4. Turn the ignition switch ON (II).
Is DTC P1443 indicated?
YES - Go to step 5.
NO - Intermittent failure, system is OK at this time. Check for poor connections or loose terminals at the high voltage contactor, bypass contactor, MPI module and at the MCM.
5. Turn the ignition switch OFF.
6. Turn the battery module switch OFF, and wait 5 minutes.
7. Remove the IPU lid, and make sure there is 30 V or less at the junction terminals.
8. Turn the ignition switch ON (II).
9. Monitor voltage between MCM connector terminal AS and ground. When you turn the ignition switch OFF and then back ON (II), there should be about 12 V. When you turn the ignition switch OFF, the voltage should remain for about 10 seconds. Do this same check between MCM connector terminal A6 and ground.
Is there battery voltage?
YES - 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.
NO - Go to step 10.
10. Turn the ignition switch OFF.
11. Disconnect the junction board 4P connector.
12. Check for continuity between the junction board 4P connector terminals No. 3 and No. 4.
Is there about 12 Ohms ?
YES - Replace the battery module.
NO - Go to step 13.
13. Check for continuity between the junction board 4P connector terminals No. 1 and No. 2.
Is there about 12 Ohms?
YES - Replace the battery module.
NO - Go to step 14.
14. Substitute a known-good DC-DC converter and recheck.
Is there about 12 Ohms?
YES - Replace the DC-DC converter.
NO - Go to step 15.
15. Substitute a known-good MPI module and recheck.
Is there about 12 Ohms?
YES - Replace the MPI 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.