Idle Control System: Diagnosis Honda Fit GE

Alternator FR Signal Circuit Troubleshooting

Note. Information marked with an asterisk (*1) applies to '09-10 models and '11-12 models (M/T). Information marked with an asterisk (*2) applies to '11-12 models (A/T).

Scheme 260

1. Start the engine, and let it idle.
2. Monitor the ALTERNATOR in the DATA LIST with the HDS.
3. Check if the indicated percentage varies when the headlight switch is turned on. Does the percentage vary? YES: The alternator signal circuit is OK. NO: Go to step 4 .
4. Turn the headlight switch off and the ignition switch to LOCK (0).
5. Jump the SCS line with the HDS.
6. Disconnect the alternator 4P connector.
7. Disconnect ECM/PCM connector B (49P).
8. Check for continuity between body ground and ECM/PCM connector terminal B47. Is there continuity? YES: Repair short in the wire between the ECM/PCM (B47) and the alternator. NO: Troubleshoot the alternator and regulator circuit (see «ALTERNATOR AND REGULATOR CIRCUIT TROUBLESHOOTING»(ref-320439-S28187664442009071400000) ). Update the ECM/PCM if it does not have the latest software (see «ECM/PCM UPDATE»(ref-320426-S22945234462009071400000) ), or substitute a known-good ECM/PCM (see «SUBSTITUTING THE ECM/PCM»(ref-320425-S18610926012009071400000) ), then recheck. If the symptom/indication goes away with a known-good ECM/PCM, replace the original ECM/PCM (see «ECM/PCM REPLACEMENT»(ref-320426-S21651098282009071400000) ).

Scheme 261

Scheme 262

Scheme 263

1. Turn the ignition switch to ON (II).
2. Check the BRAKE SWITCH in the DATA LIST with the HDS. Does it indicate OFF? YES: Go to step 3 . NO: Inspect the brake pedal position switch (see «BRAKE PEDAL AND BRAKE PEDAL POSITION SWITCH ADJUSTMENT»(ref-320428-S41600993742009071400000) ).
3. Press the brake pedal, and check the BRAKE SWITCH in the DATA LIST with the HDS. Does it change to ON? YES: The brake pedal position switch signal circuit (BKSW line) is OK. NO: Go to step 4 .
4. Turn the ignition switch to LOCK (0).
5. Jump the SCS line with the HDS.
6. Disconnect the brake pedal position switch 4P connector.
7. Disconnect ECM/PCM connector A (49P).
8. Check for continuity between ECM/PCM connector terminal A42 and body ground. Is there continuity? YES: Repair short in the wire between the ECM/PCM (A42) and the brake pedal position switch. Also, replace the No. 24 STOP/HORN (10 A) fuse. NO: Go to step 9 .
9. Connect brake pedal position switch 4P connector terminal No. 2 to body ground with a jumper wire.
10. Check for continuity between ECM/PCM connector terminal A42 and body ground. Is there continuity? YES: Repair open or short in the wire between the brake pedal position switch and the No. 24 STOP/HORN (10 A) fuse. Also, inspect the brake pedal position switch (see «BRAKE PEDAL AND BRAKE PEDAL POSITION SWITCH ADJUSTMENT»(ref-320428-S41600993742009071400000) ). NO: Repair open in the wire between the ECM/PCM (A42) and the brake pedal position switch.

Idle Speed Inspection

Note. Before checking the idle speed, check these items: The malfunction indicator lamp (MIL) has not been reported on, and there are no DTCs. Ignition timing Spark plugs Air cleaner PCV system Apply the parking brake, and make sure the headlights are off.

Scheme 264

1. Disconnect the evaporative emission (EVAP) canister purge valve connector.
2. Connect the HDS to the data link connector (DLC) (A) located under the driver's side of the dashboard.
3. Make sure the HDS communicates with the ECM/PCM. If it doesn't, go to «DLC CIRCUIT TROUBLESHOOTING»(ref-320426-S32678800202009071400000) .
4. Start the engine. Hold the engine speed at 3,000 rpm without load (A/T in P or N, M/T in neutral) until the radiator fan comes on, then let it idle.
5. Check the idle speed without load conditions: headlights, blower fan, radiator fan, and air conditioner off. Idle speed should be: IDLE SPEED REFERENCE TABLE M/T 700 ± 50 rpm A/T 700 ± 50 rpm (in P or N)
6. Let the engine idle for 1 minute with high electric load (A/C switch on, temperature set to max cool, blower fan on high, and headlights on high beam). Idle speed should be: IDLE SPEED REFERENCE TABLE M/T 790 ± 50 rpm A/T 790 ± 50 rpm (in P or IM) NOTE: If the idle speed is not within specification, do «ECM/PCM IDLE LEARN PROCEDURE»(ref-320447-S03803966382009071400000) . If the idle speed is still not within specification, go to symptom troubleshooting.
7. Reconnect the EVAP canister purge valve connector.