P1643
DTC P1643: QBATT Battery Signal Circuit High Input1. Reset the ECM.
2. Turn the ignition switch ON (II).
Is DTC P1642 or P1643 indicated?
YES - Go to step 3.
NO - Intermittent failure, system is OK at this time. Check for poor connections or loose wires at the motor control module and at the ECM.
3. Turn the ignition switch OFF.
4. Remove the IPU cover, and disconnect motor control module connector C (31P).
5. Turn the ignition switch ON (II).
6. Measure voltage between ECM connector terminal D13 and body ground.
Is there about 5 V?
YES - Go to step 10.
NO - Go to step 7.
7. Turn the ignition switch OFF.
8. Disconnect ECM connector D (16P).
9. Check for continuity between ECM connector terminal D13 and body ground.
Is there continuity?
YES - Repair short in the wire between the ECM (D13) and the motor control module.
NO - Update the ECM if it does not have the latest software, or substitute a known-good ECM, then recheck. If the symptom/indication goes away with a known-good ECM, replace the original ECM.
10. Turn the ignition switch OFF.
11. Disconnect ECM connector D (16P).
12. Check for continuity between ECM connector terminal D13 and motor control module connector terminal C16.
Is there continuity?
YES - Replace the battery module.
NO - Repair open in the wire between the ECM (D13) and the motor control module.