K20Z1 Engine (2005-2006 Models)

Turn the ignition switch ON (II).
Does the charging system indicator come on?
1. YES - Go to step 2.
2. NO - Go to step 11.
Shift to Neutral, and start the engine. Hold the engine speed at 2,000 RPM for 1 minute.
Does the charging system indicator go off?
1. YES - Charging system indicator circuit is OK. Go to the Alternator and Regulator Circuit Troubleshooting (see ALTERNATOR AND REGULATOR CIRCUIT TROUBLESHOOTING ).
2. NO - Go to step 3.
Do the gauge assembly self-diagnostic function procedure (see SELF-DIAGNOSTIC FUNCTION ).
Does the charging system indicator flash?
1. YES - Go to step 4.
2. NO - Replace the gauge assembly (see GAUGE ASSEMBLY REPLACEMENT ).
Turn the ignition switch OFF.
Disconnect the engine wire harness 6P connector from the starter subharness 6P connector.
Turn the ignition switch ON (II).
Does the charging system indicator go off?
1. YES - Replace the alternator (see ALTERNATOR REMOVAL AND INSTALLATION ) or repair the alternator (see EXPLODED VIEW - K20A2, K20Z1 ENGINES ).
2. NO - Go to step 7.
Turn the ignition switch OFF.
Connect the Honda Diagnostic System (HDS) to the data link connector (DLC) (see step 2 on IF THE MIL (MALFUNCTION INDICATOR LAMP) HAS COME ON ). Turn the ignition switch ON (II), and jump the SCS line with the HDS, then turn the ignition switch OFF.
NOTE: This step must be done to protect the engine control module (ECM) from damage.
Disconnect ECM connector B (24P).
Check for continuity between ECM connector terminal B10 and body ground.

Fig 1: Checking For Continuity Between ECM Connector Terminal B10 And Body Ground
Courtesy of AMERICAN HONDA MOTOR CO., INC.

Is there continuity?
1. YES - Repair a short in the wire between the alternator and the ECM.
2. NO - Update the ECM if it does not have the latest software (see HOW TO UPDATE THE ECM/PCM ), or substitute a known-good ECM (see HOW TO SUBSTITUTE THE ECM/PCM (2002-2004 MODELS) ), then recheck. If the symptom/indication goes away with a known-good ECM, replace the original ECM (see ECM/PCM REPLACEMENT ).
Do the gauge assembly self-diagnostic function procedure (see SELF-DIAGNOSTIC FUNCTION ).
Does the charging system indicator flash?
1. YES - Go to step 12.
2. NO - Replace the gauge assembly (see GAUGE ASSEMBLY REPLACEMENT ).
Turn the ignition switch OFF.
Disconnect the engine wire harness 6P connector from the starter subharness 6P connector.
Connect engine wire harness 6P connector terminal No. 6 and body ground with a jumper wire.

Fig 2: Connecting Engine Wire Harness 6P Connector Terminal No. 6 And Body Ground With Jumper Wire
Courtesy of AMERICAN HONDA MOTOR CO., INC.
Turn the ignition switch ON (II).
Does the charging system indicator come on?
1. YES - Replace the alternator (see ALTERNATOR REMOVAL AND INSTALLATION ) or repair the alternator (see EXPLODED VIEW - K20A2, K20Z1 ENGINES ).
2. NO - Go to step 16.
Connect the HDS to the DLC. Turn the ignition switch ON (II), and jump the SCS line with the HDS, then turn the ignition switch OFF.
NOTE: This step must be done to protect the ECM from damage.
Disconnect ECM connector B (24P).
Check for continuity between ECM connector terminal B10 and body ground.

Fig 3: Checking For Continuity Between ECM Connector Terminal B10 And Body Ground
Courtesy of AMERICAN HONDA MOTOR CO., INC.

Is there continuity?
1. YES - Update the ECM if it does not have the latest software (see HOW TO UPDATE THE ECM/PCM ), or substitute a known-good ECM (see HOW TO SUBSTITUTE THE ECM/PCM (2002-2004 MODELS) ), then recheck. If the symptom/indication goes away with a known-good ECM, replace the original ECM (see ECM/PCM REPLACEMENT ).
2. NO - Repair an open in the wire between the alternator and the ECM.