DTC P0175: BANK 2 SYSTEM TOO RICH Honda Passport II

Note. Bank 2 refers to left cylinder bank.

Diagnostic Aids

An intermittent may be caused by a poor connection, rubbed-through wire insulation or a broken wire inside insulation. Inspect harness connectors for backed-out terminals, improper mating, broken locks, improperly formed or damaged terminals, poor terminal-to-wire connection, and damaged harness. If DTC cannot be duplicated, check scan tool FAILURE RECORDS to determine mileage since last DTC was set.

1. Perform On-Board Diagnostic (OBD) System Check. See BASIC DIAGNOSTIC PROCEDURES article. Read and record FREEZE FRAME and/or FAIL RECORDS data for each DTC set. Go to next step.
2. If any DTCs other than P0172 and P0175 are set, diagnose them first before proceeding. If no other DTCs are set, go to next step.
3. Operate vehicle in closed loop mode while using scan tool to read BANK 1 L.T. FUEL TRIM values. If values are not as specified, go to next step. If L.T. FUEL TRIM value is less than -15 percent for A/T and is less than -12 percent for M/T, go to step 5 .
4. Using scan tool, read and record FAIL RECORDS data. Clear DTCs and operate vehicle within FAILURE RECORDS conditions. If DTC P0175 is set, go to next step. If DTC P0175 is not set, check for an intermittent problem. See «DIAGNOSTIC AIDS»(ref-89316-S00140072292001022800000) .
5. If DTC P0172 is also set, go to next step. If DTC P0172 is not set, go to step 15 .
6. Check air filter element condition. Replace air filter element if necessary. Retest system. If air filter element is okay, go to next step.
7. Check for collapsed or restricted air intake duct. If a problem is found, repair as necessary. Retest system. If no problem is found, go to next step.
8. Check MAF inlet screen for blockage or foreign objects which may partially block airflow sample through MAF sensor. If a problem is found, repair as necessary. Retest system. If no problem is found, go to next step.
9. Start engine. If a high or unsteady idle condition exists, go to next step. If Idle is okay, go to step 11 .
10. Turn ignition off. Check throttle body bore and throttle plate for restriction or foreign objects. Check for clogged IAC passages. If a problem is found, repair as necessary. Retest system. If no problem is found, go to next step.
11. Disconnect vacuum hose from fuel pressure regulator and check it for presence of fuel. If fuel is present, replace fuel pressure regulator. Retest system. If no fuel is present, go to next step.
12. Turn ignition on. Using scan tool, read TP ANGLE while slowly depressing accelerator pedal. If TP ANGLE increases steadily from zero percent at closed throttle to 100 percent at wide open throttle, go to next step. If TP ANGLE does not increase as specified, go to step 19 .
13. Disconnect MAF sensor connector. Operate vehicle in closed loop mode while monitoring scan tool BANK 1 L.T. and BANK 1 S.T. FUEL TRIM. If both FUEL TRIM values decrease to about zero percent, go to step 20 . If FUEL TRIM values do not decrease to about zero percent, go to next step.
14. Perform FUEL SYSTEM PRESSURE TEST. See BASIC DIAGNOSTIC PROCEDURES article. If a problem is found, repair as necessary. Retest system. If no problem is found, go to next step.
15. Turn ignition on. Connect test light between canister purge solenoid connector terminals. If test light comes on, go to next step. If test light does not come on, replace PCM. Retest system.
16. Using an ohmmeter, check for continuity to ground in Red/Blue wire between PCM connector "A" terminal No. 15 and canister purge solenoid connector. See PIN VOLTAGE CHARTS. If continuity exists, repair short to ground. Retest system. If continuity to ground does not exist, go to next step.
17. Perform injector balance test. See FUEL SYSTEM in SYSTEM & COMPONENT TESTING article. If a problem is found, repair as necessary. Retest system. If no problem is found, go to next step.
18. Remove HO2S No. 1 and check for silicone contamination (powdery white deposit). If HO2S No. 1 is contaminated, replace HO2S No. 1. Retest system. If HO2S No. 1 is not contaminated, check for an intermittent problem. See «DIAGNOSTIC AIDS»(ref-89316-S00140072292001022800000) .
19. Check for loose TP sensor mounting screws. Adjust TP sensor if necessary. If mounting screws are tight, replace TP sensor. Retest system.
20. Replace MAF sensor. Retest system.

An open or short in injector circuit will set DTC. The open or short will also cause a misfire and inoperative injector. A misfire DTC will be set indicating which cylinder is malfunctioning. Excessively high or low long and short term fuel trim indicate the possibility of a bad injector. See INJECTOR COIL TEST in SYSTEM & COMPONENT TESTING article to check injector.

1. Perform On-Board (OBD) System Check. Read and record FREEZE FRAME and/or FAIL RECORDS data for each DTC set. Go to next step.
2. Attempt to start engine. If engine starts, go to next step. If engine does not start, see BASIC DIAGNOSTIC PROCEDURES article.
3. Using scan tool, clear DTCs. Start and run engine for one minute and observe scan tool display. If any DTC from P0201 to P0206 resets, go to step 5 . If no DTC resets, go to next step.
4. With ignition on and engine off, use scan tool to read FREEZE FRAME DATA and note parameters. Start engine and operate vehicle within FAILURE RECORDS conditions. If any DTC from P0201 to P0206 resets, go to next step. If no DTC resets, check for an intermittent problem. See «DIAGNOSTIC AIDS»(ref-89316-S18388065712001022800000) .
5. Turn engine off. Disconnect appropriate injector harness connector related to DTC. Connect an injector tester (noid-light) to injector harness connector. Disable secondary ignition system to prevent engine from starting and crank engine. If noid-light blinks, see INJECTOR COIL TEST in SYSTEM & COMPONENT TESTING article. If noid-light does not blink, go to next step.
6. If noid-light was on steady in previous step, go to next step. If noid-light did not come on in previous step, go to step 8 .
7. Disconnect PCM connector containing affected injector circuit. Connect test light between battery positive terminal and affected injector driver circuit at harness connector. If test light comes on, repair short to ground in injector driver circuit. If test light does not come on, replace PCM. Retest system.
8. Disconnect injector harness connector. Using an ohmmeter connected to Red/Blue wire of injector harness connector, probe wire for affected cylinder. If continuity is present, go to next step. If continuity is not present, repair open in injector harness wire. Retest system.
9. At PCM side of injector harness connector, check for short to voltage in affected cylinder wire. If short to voltage exists, repair short in affected cylinder wire. Retest system. If short to voltage does not exist, go to next step.
10. Check for open circuit in affected cylinder wire between PCM and injector harness connector. Repair as necessary. If wires are okay, replace PCM. Retest system.

Scan tool message MISFIRE CUR. #1-6, is helpful for determining if only a single cylinder is affected by misfire. Check ignition coil for cracks or damage. Substitute a known-good ignition coil. Numerous short trip drives (under 3 miles), may fuel foul spark plugs and set DTC. If DTC cannot be duplicated, check scan tool FAILURE RECORDS to determine mileage since last DTC was set.

1. Perform On-Board (OBD) System Check. Read and record FREEZE FRAME and/or FAIL RECORDS data for each DTC set. Go to next step.
2. Start engine and run at idle. Using scan tool, read and record FREEZE FRAME data. Operate vehicle within FAILURE RECORDS conditions. Read MISFIRE CUR # display for each cylinder. If MISFIRE CUR # increases (indicating an occurring misfire) for any cylinder, go to next step. If MISFIRE CUR # does not increase, check for an intermittent problem. See «DIAGNOSTIC AIDS»(ref-89316-S27846243562001022800000) .
3. Check vacuum hoses for splits, kinks or improper connections. If a problem is found, repair as necessary. Retest system. If no problem is found, go to next step.
4. Check intake manifold, injector "O" rings, EGR valve and EGR feed pipes for vacuum leaks. If a problem is found, repair as necessary. Retest system. If no problem is found, go to next step.
5. Check PCV valve for improper installation or damaged hose. If a problem is found, repair as necessary. Retest system. If no problem is found, go to next step.
6. Inspect MAF inlet screen for foreign objects or damage that may block airflow to MAF sensor. Repair as necessary. Retest system. If inlet screen is okay, go to next step.
7. Remove EGR valve and inspect valve, seat and passages for damage. Inspect valve pintle to ensure it is not sticking partially open. If a problem is found, repair as necessary. Retest system. If no problem is found, go to next step.
8. Install a spark tester on spark plug wire at spark plug end for cylinder indicating a misfire. Crank engine and check for a strong Blue spark. Repeat procedure for each affected cylinder. If spark is okay on all cylinders, go to step 13 . If spark is not okay at all cylinders, go to next step.
9. Remove ignition coil related to misfiring cylinder. Check ignition coil for cracks or carbon tracking. If a problem is found, replace damaged coil. Retest system. If no problem is found, go to next step.
10. Remove spark plug(s) associated with misfiring cylinder(s). Check spark plugs for excessive fouling. If spark plugs are excessively fouled, diagnose and repair mechanical engine problem. If spark plugs are not excessively fouled, go to next step.
11. Check spark plug insulators for cracks, carbon tracking or other damage. If a problem is found, replace faulty spark plug(s). Retest system. If no problem is found, go to next step.
12. Disconnect MAF sensor harness connector. Operate vehicle in closed loop. while monitoring BANK 1 L.T. FUEL TRIM and BANK 1 S.T. FUEL TRIM parameters on scan tool. If L.T. FUEL TRIM decreases to less than 20 percent and ST FUEL TRIM decreases to less than 50 percent, replace HEX ignition coil control module (3.2L), or ignition coil (3.5L). On all models, if scan tool display is not as specified, replace ignition coil related to affected cylinder. Retest system.
13. Ensure PCM injector ground, power ground and sensor ground connections are clean and tight. Repair as necessary. Retest system. If connections are okay, go to next step.
14. See FUEL PUMP PRESSURE TEST in BASIC DIAGNOSTIC PROCEDURES article. If a problem was found, repair as necessary. Retest system. If no problem was found, go to next step.
15. Check for fuel contamination. If fuel is contaminated, repair as necessary. Retest system. If fuel is okay, go to next step.
16. Perform injector balance test. See FUEL SYSTEM in SYSTEM & COMPONENT TESTING article. If a problem is found, repair as necessary. Retest system. If no problem is found, go to next step.
17. Diagnose mechanical engine problems such as faulty camshaft, leaking or sticking valves, weak valve springs, damaged piston rings, loose or worn rocker arms, incorrect valve timing, leaking head gasket or loose or broken motor mounts. If a problem is found, repair as necessary. Retest system. If no problems are found, go to next step.
18. Check for a transmission Torque Converter Clutch (TCC) problem. See HYDRA-MATIC 4L30-E article in AUTOMATIC TRANSMISSIONS. Repair as necessary. If no problem is found, replace MAF sensor. Retest system.

Test system grounds. Check injector. See INJECTOR COIL TEST in SYSTEM & COMPONENT TESTING article. Check spark plugs for cracked insulator, carbon tracking, incorrect gap and wear. Check ignition coil for cracks or damage. Substitute a known-good ignition coil.

1. Perform On-Board Diagnostic (OBD) System Check. See BASIC DIAGNOSTIC PROCEDURES article. Read and record FREEZE FRAME and/or FAIL RECORDS data for each DTC set. Go to next step.
2. Start engine and run at idle. Using scan tool, read and record FREEZE FRAME data. Operate vehicle within FAILURE RECORDS conditions. Read MISFIRE CUR # display for appropriate cylinder. If MISFIRE CUR # increases (indicating an occurring misfire) for affected cylinder, go to step 4 . If MISFIRE CUR. # does not increase, go to next step.
3. Monitor MISFIRE HIST. # while operating vehicle and attempting to duplicate conditions which caused DTC to set. If MISFIRE HIST. # increases, go to next step. If MISFIRE HIST. # does not increase, check for an intermittent problem. See «DIAGNOSTIC AIDS»(ref-89316-S18659103762001022800000) .
4. Check vacuum hoses for splits, kinks or improper connections. Check intake manifold for vacuum leak. If a problem is found, repair as necessary. Retest system. If no problem is found, go to next step.
5. Install spark tester at affected cylinder spark plug wire. Crank engine. If a strong Blue spark is present, go to step 8 . If no spark or weak spark is present, go to next step.
6. Remove ignition coil related to misfiring cylinder. Check ignition coil for cracks or carbon tracking. If a problem is found, replace damaged coil. Retest system. If no problem is found, go to next step.
7. Measure primary coil resistance. On SLX and Trooper, resistance should be 0.8-1.3 ohms. On all others, resistance should be 2.6-2.7 k/ohms. Replace ignition coil if resistance is not as specified. If coil is okay, replace ignition control module. Retest system.
8. Remove spark plug associated with misfiring cylinder. Check spark plug for excessive fouling. If spark plug is excessively fouled, diagnose and repair mechanical engine problem. If spark plug is not excessively fouled, go to next step.
9. Check spark plug insulator for cracks, carbon tracking or other damage. If a problem is found, replace faulty spark plug. Retest system. If no problem is found, go to next step.
10. Perform injector balance test. See FUEL SYSTEM in SYSTEM & COMPONENT TESTING article. If a problem is found, repair as necessary. Retest system. If no problem is found, go to next step.
11. Inspect injector "O" rings for vacuum leaks. If a problem is found, repair as necessary. Retest system. If no problem is found, go to next step.
12. Diagnose mechanical engine problems such as faulty camshaft, leaking or sticking valves, weak valve springs, damaged piston rings, loose or worn rocker arms, incorrect valve timing, leaking head gasket or loose or broken motor mounts. If a problem is found, repair as necessary. Retest system. If no problems are found, check for an intermittent problem. See «DIAGNOSTIC AIDS»(ref-89316-S18659103762001022800000) .