DTC 21

DTC 21: Motor Power Inverter (MPI) Module Current Signal Circuit Problem
1. Reset the MCM.
2. Turn the ignition switch ON (II).
Is DTC 21 indicated?
YES- Go to step 3.
NO- Intermittent failure, system is OK at this time. Check for poor connections or loose terminals at the MPI module current sensor and at the MCM.
3. Substitute a known-good MCM and recheck.
Is DTC 21 indicated?
YES- Replace these items
^ MPI module
^ Battery modules
NO- Replace the original MCM.

DTC 23: Motor Power Inverter (MPI) Module Current Signal/Battery Current Signal Circuit Problem
1. Reset the MCM.
2. Turn the ignition switch ON (II) and watch IMA system indicator.
Is DTC 65 or 79 indicated?
YES- Do the DTC 65 troubleshooting or the DTC 79 troubleshooting and recheck.
NO- Go to step 3.
3. Remove the No. 15 EPS (40 A) fuse from the underhood fuel relay box.
4. Start the engine. Raise the engine to 3,500 rpm with no load (in neutral) until the state of charge indication is normal.
5. Accelerate using wide open throttle from 32 - 64 mph (20 - 40 km/h) in the 3rd gear, and decelerate using fully closed throttle to 32 mph (20 km/h).
6. Watch the IMA system indicator.
Is DTC 23 indicated?
YES- Substitute a known-good BCM module, and the battery module, and recheck. If the symptom/ indication goes away, replace the original BCM module and the battery module.
NO- Intermittent failure, system is OK at this time. Check for poor connections or loose wires at the MPI module current sensor/battery current sensor and at the MCM.