P1645

DTC P1645: MOTFSB Motor Control Module Signal Malfunction

NOTE: Information marked with an asterisk (*1) applies to DTC P1645; information marked with *2 applies to DTC P1646.

1. Reset the ECM with the HDS.
2. Turn the ignition switch ON (II).
3. Check for Temporary DTCs or DTCs with the HDS.

Is DTC P1644, P1645, or P1646 indicated?

YES - Go to step 4.

NO - Intermittent failure, system is OK at this time. Check for poor connections or loose terminals at the motor control module and the ECM.

4. Turn the ignition switch OFF.
5. Remove the IPU cover, and disconnect motor control module connector A (32P).
6. Turn the ignition switch ON (II).




7. Measure voltage between ECM connector terminal D2, (D1)*1, (D3)*2 and body ground.

Is there about 5 V?

YES - Go to step 11.

NO - Go to step 8.

8. Turn the ignition switch OFF.
9. Disconnect ECM connector D (16P).




10. Check for continuity between ECM connector terminal D2, (D1)*1, (D3)*2 and body ground.

Is there continuity?

YES - Repair short in the wire between the ECM (D2,(D1)*1,(D3)*2) 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.

11. Turn the ignition switch OFF.
12. Disconnect ECM connector D (16P).




13. Check for continuity between ECM connector terminal D2, (D1)*1, (D3)*2 and motor control module connector terminal A16, (A15)*1 (A4)*2.

Is there continuity?

YES - Replace the battery module.

NO - Repair open in wire between ECM connector terminal D2 (D1)*1 (D3)*2 and the motor control module.