P0A27

DTC P0A27 (46): High Voltage Contactor/Bypass Contactor Stays Activated (2004-2005 models)

NOTE:
^ Information marked with an asterisk (*) applies to 2003 model.
^ Information marked with double asterisk (**) applies to 2004-2005 models.

1. Reset the MCM.
2. Turn the ignition switch ON (II).
3. Turn the ignition switch OFF, and wait 30 seconds.
4. Turn the ignition switch ON (II).
Is DTC P0A27** (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 DC-DC converter and at the MCM.
5. Watch the charging system indicator.
Does the charging system indicator come on?
YES-Go to step 6.
NO-Go to step 7.
6. Check for an open in the 20 A fuse or the harness on the junction board.
Are the fuse and the harness OK?
YES-Replace the DC-DC converter.
NO-Replace the battery module.
7. Turn the ignition switch OFF.
8. Turn the battery module switch OFF, and wait 5 minutes.
9. Remove the IPU lid.
10. Turn the battery module switch ON, and measure voltage at the battery module junction terminals.
Is there 100 V or more?
YES-Go to step 11.
NO-Go to step 12.
11. Disconnect the junction board 4P connector.
Does the voltage drop rapidly below 100 V within 30 seconds?
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-Replace the battery module.
12. Turn the ignition switch ON (II).
13. Turn the ignition switch OFF, and wait 1 minute.
14. Measure voltage at the battery module junction terminals.
Is there 100 V or more?
YES-Replace the DC-DC converter.
NO-Replace the MPI module.