DTC P1581 (20): Motor Power Inverter (MPI) Module Current Signal Circuit High Input; DTC P1588 (20): Motor Power Inverter (MPI) Module Current Signal Circuit High Input

NOTE:

Information marked with an asterisk (*) applies to 2005-2006 models.
Information marked with double asterisk (**) applies to 2000-2004 models.

Reset the MCM (see HOW TO RESET THE MCM ).
Turn the ignition switch ON (II).
Is DTC P1581 (20)** (P1588 (20)*) indicated?
1. YES - Go to step 3.
2. 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.
Turn the ignition switch OFF.
Turn the battery module switch OFF (see TURNING OFF POWER TO THE HIGH VOLTAGE CIRCUIT ).
Remove the IPU lid (see TURNING OFF POWER TO THE HIGH VOLTAGE CIRCUIT ).
Turn the ignition switch ON (II).
Measure voltage between MCM connector terminals B18 and B25.

Fig 1: Measuring Voltage Between MCM Connector Terminals B18 And B25
Courtesy of AMERICAN HONDA MOTOR CO., INC.

Is there less than 4.8 V?
1. YES - Substitute a known-good MCM, and recheck. If the symptom/indication goes away, replace the original MCM.
2. NO - Go to step 8.
Measure voltage between MCM connector terminals B25 and C24.

Fig 2: Measuring Voltage Between MCM Connector Terminals B25 And C24
Courtesy of AMERICAN HONDA MOTOR CO., INC.

Is there about 5 V?
1. YES - Go to step 9.
2. NO - Substitute a known-good MCM, and recheck. If the symptom/indication goes away, replace the original MCM.
Turn the ignition switch OFF.
Disconnect the junction board 16P connector.
Turn the ignition switch ON (II).
Measure voltage between junction board 16P connector terminals No. 3 and No. 11.

Fig 3: Measuring Voltage Between Junction Board 16P Connector Terminals No. 3 And 11
Courtesy of AMERICAN HONDA MOTOR CO., INC.

Is there about 5 V?
1. YES - Replace the battery module (see BATTERY MODULE REMOVAL/INSTALLATION ).
2. NO - Repair open in the wire between the MCM (B25) and the junction board.