Honda Civic. Manual — part 357

YES - Go to step 2.

NO - Go to step 14.

2. Start the engine. Hold the engine speed at 2,000 rpm for 1 minute.

Does the charging system indicator go off?

YES - Charging system indicator circuit is OK. Go to the alternator and
regulator circuit troubleshooting (see ALTERNATOR AND REGULATOR
CIRCUIT TROUBLESHOOTING ).

NO - Go to step 3.

3. Do the gauge control module self-diagnostic function procedure (see SELF-

DIAGNOSTIC FUNCTION ).

Does the charging system indicator flash?

YES - Go to step 4.

NO - Replace the gauge control module (tach) (see REPLACEMENT ).

4. Turn the ignition switch OFF.
5. Disconnect the alternator 4P connector.
6. Turn the ignition switch ON (II).

Does the charging system indicator go off?

YES - Replace the alternator (see ALTERNATOR REMOVAL AND
INSTALLATION ), or repair the alternator (see ALTERNATOR
OVERHAUL ).

NO - Go to step 7.

7. Turn the ignition switch OFF.
8. Connect the Honda Diagnostic System (HDS) to the data link connector (DLC)

(see step 2 in HOW TO USE THE HDS (HONDA DIAGNOSTIC

2008 Honda Civic GX

2006-08 ELECTRICAL Charging System (K20Z3) - Civic (All Except Si)

SYSTEM) ).

9. Turn the ignition switch ON (II).

10. Make sure the HDS communicates with the vehicle and the engine control

module (ECM). If it doesn't, troubleshoot the DLC circuit (see DLC
CIRCUIT TROUBLESHOOTING ).

11. Jump the SCS line with the HDS, then turn the ignition switch OFF.

12. Disconnect ECM connector B (44P).
13. Check for continuity between ECM connector terminal B42 and body ground.

Fig. 3: Checking Continuity Between ECM Connector Terminal B42 And
Body Ground
Courtesy of AMERICAN HONDA MOTOR CO., INC.

Is there continuity?

YES - Repair short in the wire between the alternator and the ECM.

NO - Update the ECM if it does not have the latest software (see UPDATING
THE ECM ), or substitute a known-good ECM (see SUBSTITUTING THE
ECM ), then recheck. If the symptom/indication goes away with a known-good
ECM, replace the original ECM (see ECM REPLACEMENT ).

14. Do the gauge control module self-diagnostic function procedure (see SELF-

NOTE:

This step must be done to protect the ECM from
damage.

2008 Honda Civic GX

2006-08 ELECTRICAL Charging System (K20Z3) - Civic (All Except Si)

DIAGNOSTIC FUNCTION ).

Does the charging system indicator flash?

YES - Go to step 15.

NO - Replace the gauge control module (tach) (see REPLACEMENT ).

15. Turn the ignition switch OFF.
16. Disconnect the alternator 4P connector.
17. Connect alternator 4P connector terminal No. 3 and body ground with a jumper

wire.

Fig. 4: Connecting Alternator 4P Connector Terminal No. 3 And Body
Ground With Jumper Wire
Courtesy of AMERICAN HONDA MOTOR CO., INC.

18. Turn the ignition switch ON (II).

Does the charging system indicator come on?

YES - Replace the alternator (see ALTERNATOR REMOVAL AND
INSTALLATION ), or repair the alternator (see ALTERNATOR
OVERHAUL ).

NO - Go to step 19.

19. Turn the ignition switch to LOCK (0).
20. Connect the Honda Diagnostic System (HDS) to the data link connector (DLC)

2008 Honda Civic GX

2006-08 ELECTRICAL Charging System (K20Z3) - Civic (All Except Si)

(see step 2 in HOW TO USE THE HDS (HONDA DIAGNOSTIC
SYSTEM) ).

21. Turn the ignition switch ON (II).
22. Make sure the HDS communicates with the vehicle and the ECM. If it doesn't,

troubleshoot the DLC circuit (see DLC CIRCUIT TROUBLESHOOTING ).

23. Jump the SCS line with the HDS, then turn the ignition switch OFF.

24. Disconnect ECM connector B (44P).
25. Check for continuity between ECM connector terminal B42 and alternator 4P

connector terminal No. 3.

Fig. 5: Checking Continuity Between ECM Connector Terminal B42 And
Body Ground
Courtesy of AMERICAN HONDA MOTOR CO., INC.

Is there continuity?

YES - Update the ECM if it does not have the latest software (see
UPDATING THE ECM ), or substitute a known-good ECM (see
SUBSTITUTING THE ECM ), then recheck. If the symptom/indication goes
away with a known-good ECM, replace the original ECM (see ECM
REPLACEMENT ).

NOTE:

This step must be done to protect the ECM from
damage.

2008 Honda Civic GX

2006-08 ELECTRICAL Charging System (K20Z3) - Civic (All Except Si)