Idle Control System: Overview Honda Fit I

Scheme 242

Note. Before you troubleshoot, record all freeze data and any on-board snapshot, and review the general troubleshooting information (see GENERAL TROUBLESHOOTING INFORMATION ).

1. Turn the ignition switch ON (II).
2. Clear the DTC with the HDS.
3. Start the engine. Hold the engine speed at 3,000 rpm without load (in Park or neutral) until the radiator fan comes on, then let it idle.
4. Check under these DATA LIST parameter conditions with the HDS: ECT SENSOR 1 above 156°F (70°C) IAT SENSOR above 32°F (0°C) Vehicle speed is 0 mph (0 km/h) ST FUEL TRIM between 0.69-1.47 FSS is CLOSED
5. Monitor the OBD STATUS for DTC P0506 in the DTCs MENU with the HDS. Does the screen indicate FAILED? YES - Go to step 6 . NO - If the screen indicates PASSED, go to step 15 . If the screen indicates EXECUTING, keep idling until a result comes on. If the screen indicates OUT OF CONDITION, go to step 4 and recheck.
6. Remove the intake air duct from the throttle body (see «THROTTLE BODY REMOVAL/INSTALLATION»(ref-291400-S02025488092008072800000) ).
7. Check for dirt, carbon, or damage in the throttle bore. Is there dirt, carbon, or damage in the throttle bore? YES - If there is dirt or carbon, clean the throttle body (see «THROTTLE BODY CLEANING»(ref-291400-S23924038352008072800000) ). Also check for damage to the air cleaner element (see «AIR CLEANER REMOVAL/INSTALLATION»(ref-291400-S28864655392008072800000) ), then go to step 9 . If there is damage in the throttle bore, go to step 8 . NO - Check the A/C system, then go to step 9 .
8. Replace the throttle body (see «THROTTLE BODY REMOVAL/INSTALLATION»(ref-291400-S02025488092008072800000) ).
9. Reset the ECM/PCM with the HDS.
10. Do the «ECM/PCM IDLE LEARN PROCEDURE»(ref-291413-S23447131872008072800000) .
11. Start the engine. Hold the engine speed at 3,000 rpm without load (in Park or neutral) until the radiator fan comes on, then let it idle.
12. Check under these DATA LIST parameter conditions with the HDS: ECT SENSOR 1 above 156°F (70°C) IAT SENSOR above 32°F (0°C) Vehicle speed is 0 mph (0 km/h) ST FUEL TRIM between 0.69-1.47 FSS is CLOSED
13. Check for Temporary DTCs or DTCs with the HDS. Is DTC P0506 indicated? YES - Go to step 19 . NO - Go to step 14 .
14. Monitor the OBD STATUS for DTC P0506 in the DTCs MENU with the HDS. Does the screen indicate PASSED? YES - Troubleshooting is complete. If any other Temporary DTCs or DTCs were indicated in step 13, go to the indicated DTCs troubleshooting. NO - If the screen indicates FAILED, go to step 19 . If the screen indicates EXECUTING, keep idling until a result comes on. If the screen indicates OUT OF CONDITION, go to step 12 .
15. Remove the intake air duct from the throttle body (see «THROTTLE BODY REMOVAL/INSTALLATION»(ref-291400-S02025488092008072800000) ).
16. Check for dirt, carbon, or damage in the throttle bore. Is there dirt, carbon, or damage in the throttle bore? YES - If there is dirt or carbon, clean the throttle body (see «THROTTLE BODY CLEANING»(ref-291400-S23924038352008072800000) ). Also check for damage to the air cleaner element (see «AIR CLEANER REMOVAL/INSTALLATION»(ref-291400-S28864655392008072800000) ), then go to step 9 . If there is damage in the throttle bore, go to step 8 . NO - Go to step 17 .
17. Recheck with different load conditions (turn on the headlights, blower motor, rear window defogger and/or A/C, change the gear position, etc.).
18. Monitor the OBD STATUS for DTC P0506 in the DTCs MENU with the HDS. Does the screen indicate PASSED? YES - Intermittent failure, the system is OK at this time. NO - If the screen indicates FAILED, check the A/C system, then go to step 1 and recheck. If the screen indicates EXECUTING, keep idling until a result comes on. If the screen indicates OUT OF CONDITION, go to step 17 and recheck.
19. Update the ECM/PCM if it does not have the latest software (see «UPDATING THE ECM/PCM»(ref-291410-S41633658632008072800000) ), or substitute a known-good ECM/PCM (see «SUBSTITUTING THE ECM/PCM»(ref-291410-S09944723422008072800000) ).
20. Start the engine. Hold the engine speed at 3,000 rpm without load (in Park or neutral) until the radiator fan comes on, then let it idle.
21. Check under these DATA LIST parameter conditions with the HDS: ECT SENSOR 1 above 156°F (70°C) IAT SENSOR above 32°F (0°C) Vehicle speed is 0 mph (0 km/h) ST FUEL TRIM between 0.69-1.47 FSS is CLOSED
22. Check for Temporary DTCs or DTCs with the HDS. Is DTC P0506 indicated? YES - Check for poor connections or loose terminals at the throttle body, the throttle actuator control module, and the ECM/PCM. If the ECM/PCM was updated, substitute a known-good ECM/PCM (see «SUBSTITUTING THE ECM/PCM»(ref-291410-S09944723422008072800000) ), then go to step 20 . If the ECM/PCM was substituted, go to step 1 . NO - Go to step 23 .
23. Monitor the OBD STATUS for DTC P0506 in the DTCs MENU with the HDS. Does the screen indicate PASSED? YES - If the ECM/PCM was updated, troubleshooting is complete. If the ECM/PCM was substituted, replace the original ECM/PCM (see «ECM/PCM REPLACEMENT»(ref-291411-S17209936142008072800000) ). If any other Temporary DTCs or DTCs were indicated in step 22, go to the indicated DTCs troubleshooting. NO - If the screen indicates FAILED, check for poor connections or loose terminals at the throttle body, the throttle actuator control module, and the ECM/PCM. If the ECM/PCM was updated, substitute a known-good ECM/PCM (see «SUBSTITUTING THE ECM/PCM»(ref-291410-S09944723422008072800000) ), then go to step 20 . If the ECM/PCM was substituted, go to step 1 . If the screen indicates EXECUTING, keep idling until a result comes on. If the screen indicates OUT OF CONDITION, go to step 20 .

Note. Before you troubleshoot, record all freeze data and any on-board snapshot, and review the general troubleshooting information (see GENERAL TROUBLESHOOTING INFORMATION ).

1. Turn the ignition switch ON (II).
2. Clear the DTC with the HDS.
3. Start the engine. Hold the engine speed at 3,000 rpm without load (in Park or neutral) until the radiator fan comes on, then let it idle.
4. Monitor the OBD STATUS for DTC P0507 in the DTCs MENU with the HDS. Does the screen indicate FAILED? YES - Go to step 5 . NO - If the screen indicates PASSED, intermittent failure, the system is OK at this time. If the screen indicates EXECUTING, keep idling until a result comes on. If the screen indicates OUT OF CONDITION, recheck with different load conditions (electrical, A/C, gear position, etc.), then go to step 3 .
5. Check for vacuum leaks at these parts: PCV valve PCV hose EVAP canister purge valve Throttle body Intake manifold Brake booster hose Brake booster Are there any leaks? YES - Repair or replace the leaking part(s), then go to step 6 . NO - Go to step 6 .
6. Turn the ignition switch ON (II).
7. Reset the ECM/PCM with the HDS.
8. Do the «ECM/PCM IDLE LEARN PROCEDURE»(ref-291413-S23447131872008072800000) .
9. Start the engine. Hold the engine speed at 3,000 rpm without load (in Park or neutral) until the radiator fan comes on, then let it idle.
10. Check for Temporary DTCs or DTCs with the HDS. Is DTC P0507 indicated? YES - Go to step 12 . NO - Go to step 11 .
11. Monitor the OBD STATUS for DTC P0507 in the DTCs MENU with the HDS. Does the screen indicate PASSED? YES - Troubleshooting is complete. If any other Temporary DTCs or DTCs were indicated in step 10, go to the indicated DTCs troubleshooting. NO - If the screen indicates FAILED, go to step 12 . If the screen indicates EXECUTING, keep idling until a result comes on. If the screen indicates OUT OF CONDITION, go to step 9 .
12. Update the ECM/PCM if it does not have the latest software (see «UPDATING THE ECM/PCM»(ref-291410-S41633658632008072800000) ), or substitute a known-good ECM/PCM (see «SUBSTITUTING THE ECM/PCM»(ref-291410-S09944723422008072800000) ).
13. Start the engine. Hold the engine speed at 3,000 rpm without load (in Park or neutral) until the radiator fan comes on, then let it idle.
14. Check for Temporary DTCs or DTCs with the HDS. Is DTC P0507 indicated? YES - Check for poor connections or loose terminals at the throttle body, the throttle actuator control module, and the ECM/PCM. If the ECM/PCM was updated, substitute a known-good ECM/PCM (see «SUBSTITUTING THE ECM/PCM»(ref-291410-S09944723422008072800000) ), then go to step 13 . If the ECM/PCM was substituted, go to step 1 . NO - Go to step 15 .
15. Monitor the OBD STATUS for DTC P0507 in the DTCs MENU with the HDS. Does the screen indicate PASSED? YES - If the ECM/PCM was updated, troubleshooting is complete. If the ECM/PCM was substituted, replace the original ECM/PCM (see «ECM/PCM REPLACEMENT»(ref-291411-S17209936142008072800000) ). If any other Temporary DTCs or DTCs were indicated in step 14, go to the indicated DTCs troubleshooting. NO - If the screen indicates FAILED, check for poor connections or loose terminals at the throttle body, the throttle actuator control module, and the ECM/PCM. If the ECM/PCM was updated, substitute a known-good ECM/PCM (see «SUBSTITUTING THE ECM/PCM»(ref-291410-S09944723422008072800000) ), then go to step 13 . If the ECM/PCM was substituted, go to step 1 . If the screen indicates EXECUTING, keep idling until a result comes on. If the screen indicates OUT OF CONDITION, go to step 13 .

Scheme 243

Scheme 244

Scheme 245

1. Start the engine, and let it idle.
2. Turn the blower switch on.
3. Turn the A/C switch on.
4. Check the A/C CLUTCH in the DATA LIST with the HDS. Does it indicate ON? YES - Go to step 5 . NO - Go to step 14 .
5. Check the A/C system. Does the A/C system operate? YES - The air conditioning system circuit is OK. NO - Go to step 6 .
6. Turn the ignition switch OFF.
7. Turn the ignition switch ON (II).
8. Activate the A/C CLUTCH in the INSPECTION MENU with the HDS. Is there a clicking noise from the A/C compressor clutch? YES - Do the A/C system test (see «A/C SYSTEM TEST»(ref-291425-S07834912722008072800000) ). NO - Go to step 9 .
9. Turn the ignition switch OFF.
10. Jump the SCS line with the HDS.
11. Disconnect ECM/PCM connector E (31P).
12. Turn the ignition switch ON (II).
13. Momentarily connect ECM/PCM connector terminal E18 to body ground with a jumper wire several times. Is there a clicking noise from the A/C compressor clutch? YES - Update the ECM/PCM if it does not have the latest software (see «UPDATING THE ECM/PCM»(ref-291410-S41633658632008072800000) ), or substitute a known-good ECM/PCM (see «SUBSTITUTING THE ECM/PCM»(ref-291410-S09944723422008072800000) ), then recheck. If the symptom/indication goes away with a known-good ECM/PCM, replace the original ECM/PCM (see «ECM/PCM REPLACEMENT»(ref-291411-S17209936142008072800000) ). NO - Check for poor connections or loose terminals at the A/C clutch relay and the ECM/PCM. If the connections and terminals are OK, check the A/C clutch relay (see «POWER RELAY TEST»(ref-291408-S30734988182008072800000) ), also repair open in the wire between the ECM/PCM (E18) and the A/C clutch relay and the other A/C systems.
14. Turn the ignition switch OFF.
15. Disconnect the A/C pressure switch 2P connector.
16. Turn the ignition switch ON (II).
17. Measure voltage between ECM/PCM connector terminals A9 and E28. Is there about 5 V? YES - Repair open in the wire between the ECM/PCM (E28) and the A/C pressure switch. Go to the A/C pressure switch circuit troubleshooting (see «A/C PRESSURE SWITCH CIRCUIT TROUBLESHOOTING»(ref-291425-S36440986362008072800000) ). NO - Go to step 18 .
18. Turn the ignition switch OFF.
19. Jump the SCS line with the HDS.
20. Disconnect ECM/PCM connector E (31P).
21. Check for continuity between ECM/PCM connector terminal E28 and body ground. Is there continuity? YES - Repair short in the wire between the ECM/PCM (E28) and the A/C pressure switch. NO - Update the ECM/PCM if it does not have the latest software (see «UPDATING THE ECM/PCM»(ref-291410-S41633658632008072800000) ), or substitute a known-good ECM/PCM, then recheck (see «SUBSTITUTING THE ECM/PCM»(ref-291410-S09944723422008072800000) ). If the symptom/indication goes away with a known-good ECM/PCM, replace the original ECM/PCM (see «ECM/PCM REPLACEMENT»(ref-291411-S17209936142008072800000) ).

Scheme 246

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 and ignition switch OFF.
5. Jump the SCS line with the HDS.
6. Disconnect the alternator 4P connector.
7. Disconnect ECM/PCM connector B (24P).
8. Check for continuity between body ground and ECM/PCM connector terminal B13. Is there continuity? YES - Repair short in the wire between the ECM/PCM (B13) and the alternator. NO - Update the ECM/PCM if it does not have the latest software (see «UPDATING THE ECM/PCM»(ref-291410-S41633658632008072800000) ), or substitute a known-good ECM/PCM (see «SUBSTITUTING THE ECM/PCM»(ref-291410-S09944723422008072800000) ), then recheck. If the symptom/indication goes away with a known-good ECM/PCM, replace the original ECM/PCM (see «ECM/PCM REPLACEMENT»(ref-291411-S17209936142008072800000) ).

Scheme 247

Scheme 248

1. Turn the ignition switch 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 POSITION SWITCH TEST»(ref-291416-S04386450552008072800000) ).
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 OFF.
5. Jump the SCS line with the HDS.
6. Disconnect the brake pedal position switch 4P connector.
7. Disconnect ECM/PCM connector E (31P).
8. Check for continuity between ECM/PCM connector terminal E22 and body ground. Is there continuity? YES - Repair short in the wire between the ECM/PCM (E22) and the No. 16 HORN, STOP (15 A) fuse. Replace the No. 16 HORN, STOP (15 A) fuse. NO - Go to step 9 .
9. Check for continuity between ECM/PCM connector terminal E22 and brake pedal position switch 4P connector terminal No. 2. Is there continuity? YES - Repair open in the wire between the brake pedal position switch and the No. 16 HORN, STOP (15 A) fuse. Inspect the brake pedal position switch (see «BRAKE PEDAL POSITION SWITCH TEST»(ref-291416-S04386450552008072800000) ). NO - Repair open in the wire between the ECM/PCM (E22) and the brake pedal position switch.