Honda Accord: Common Codes & Fixes
Real-world diagnostic data for the Honda Accord. These are the codes techs see most often. Tap any code for the full vehicle-specific fix and the exact part.
80 codes have specific fixes for the Honda Accord
B0081 B0081 (seat belt pretensioner circuit) on Honda is usually the driver-side pretensioner at the B-pillar. C1651 Honda sets C1651 when the brake fluid reservoir level switch reads low or open. C1762 Honda C1762 typically points to the VSA modulator (ABS pump). C2221 C2221 steering angle sensor codes on Honda usually require a recalibration after any alignment or suspension work. C2309 On Honda VSA systems, C2309 typically means the VSA modulator has failed internally or a wheel speed sensor is giving erratic signal. P0026 Intake valve control solenoid (VTC oil control valve) on the front of the head clogs with sludge or fails internally. P0030 Honda O2 sensor heater failure is common above 100K miles. P0031 Upstream (sensor 1) oxygen sensor heater circuit develops high resistance as the sensor ages past 100K miles. P0036 The post-cat O2 sensor on Honda vehicles sits in a corrosion-prone location behind the catalytic converter. P0053 Extremely common on aging Civics — upstream air/fuel sensor heater resistance rises out of spec. P0054 Downstream O2 sensor heater resistance code — usually a simple sensor replacement after 100K miles. P0076 Intake VTC oil control valve (OCV) electrical circuit open or shorted to ground. P0076 Bank 1 intake valve control solenoid low side driver circuit open. P0077 Bank 1 intake VTC solenoid circuit high — usually an internal short to power inside the solenoid. P0106 MAP sensor signal is out of expected range. P0116 ECT performance issues often point to the 2-pin ECT sensor on the back of the engine block. P0117 Honda ECT circuit low — replace the ECT sensor (near the upper radiator hose) with Honda OEM. P0118 ECT high voltage after cooling system service — common when the sensor connector isn't fully seated. P0121 TPS performance out of range. P0122 Check the TPS connector for corroded or loose pins. P0131 Honda uses an air-fuel ratio sensor (not a standard O2 sensor) upstream. P0133 Test the upstream A/F sensor with live data -- it should respond to throttle changes within 100ms. P0134 Upstream A/F sensor has no activity. P0135 The upstream A/F sensor heater element burns out around 100-120K miles. P0136 Downstream O2 sensor circuit malfunction. P0137 Honda downstream O2 sensors last about 120-150K miles. P0139 Downstream O2 slow response on Honda — replace with Denso OEM sensor. P0140 Replace downstream (post-cat) O2 sensor with Denso OEM. P0141 Downstream O2 sensor heater has failed. P0171 Clean the MAF sensor with CRC MAF cleaner first -- dirty MAF is the easiest fix. P0203 Cylinder 3 injector circuit fault. P0300 Start with spark plugs (NGK Iridium ILZKR7B11). P0304 Perform a coil swap test first. P0325 The knock sensor on the K24 is located on the engine block below the intake manifold. P0335 The CKP sensor is behind the crank pulley near the oil pump. P0401 EGR ports in the intake manifold get completely clogged with carbon. P0402 EGR passages in the intake manifold become clogged with carbon, causing the EGR valve to stick open. P0404 The EGR valve position sensor drifts out of calibration on high-mileage K24 engines. P0405 Honda EGR valves use a lift sensor to report position. P0420 Often a downstream O2 sensor (sensor 2) rather than the cat itself. P0442 The EVAP canister vent shut valve (located near the fuel tank) fails frequently. P0457 P0457 specifically points to a fuel cap issue as the source of the EVAP leak. P0491 On older Hondas with EGR-style air injection, carbon buildup plugs the air passages in the cylinder head. P0497 P0497 indicates low EVAP purge flow. P0498 P0498 on Honda means the canister vent shut valve circuit has low voltage. P0500 Honda uses a transmission-mounted VSS. P0501 The vehicle speed sensor (VSS) on the transmission output shaft fails from fluid leaks and heat. P0505 The IACV (idle air control valve) gets clogged with carbon deposits. P0506 Idle speed drops below target on Honda K-series engines due to a dirty throttle body. P0507 High idle on Honda engines is usually a dirty throttle body or IACV. P0530 The A/C refrigerant pressure sensor fails and sends an out-of-range signal to the ECM. P0604 J-series V6 P0604 is usually an ECM internal fault after a voltage spike (jumpstart gone wrong, welding on the vehicle, etc.). P0700 P0700 on Honda often points to the transmission range switch (Neutral safety switch) or a failed torque converter lockup solenoid. P0715 The mainshaft (input) speed sensor on Honda automatics develops cracked housings that allow fluid to reach the connector. P0717 Honda automatics use a mainshaft speed sensor (countershaft speed sensor) for input speed. P0720 The countershaft (output) speed sensor on Honda automatics is located on the front of the transmission. P0730 Incorrect gear ratio on Honda automatics is most often caused by worn clutch packs inside the transmission. P0731 Gear 1 incorrect ratio on Honda automatics almost always indicates low clutch pack wear or a stuck 1st gear clutch control solenoid. P0732 Gear 2 incorrect ratio is one of the most common Honda automatic transmission failure modes. P0733 Third gear ratio errors on Honda automatics typically indicate worn 3rd gear clutch plates or a failing linear solenoid (shift solenoid C). P0734 4th gear ratio fault on Honda 4-speed and 5-speed automatics indicates 4th clutch pack failure. P0740 Torque converter clutch circuit malfunction on Honda automatics is a well-known issue. P0741 TCC stuck off or performance issue is extremely common on Honda automatics. P0744 Intermittent TCC operation on Honda automatics is one of the most common transmission complaints. P0750 Shift solenoid A (SS-A) failure on Honda automatics causes harsh 1-2 shifts or no first gear. P0751 Shift solenoid A performance issues on Honda automatics are caused by solenoid coil resistance drift or varnish restricting solenoid… P0755 Shift solenoid B (SS-B) controls the 2-3 shift on Honda automatics. P0756 Shift solenoid B performance on Honda automatics affects 2nd and 3rd gear operation. P0760 Shift solenoid C (SS-C) on Honda automatics controls overdrive engagement. P0765 Shift solenoid D on Honda automatics modulates TCC apply and release timing. P0770 Shift solenoid E on Honda automatics controls pressure regulation for smooth shift quality. P0785 Shift/timing solenoid faults on Honda automatics indicate a problem with the linear solenoid that controls shift timing and feel. P0894 Slipping on Honda automatics is the final stage of clutch pack failure. P1129 P1129 on Honda = MAP sensor signal high or lean O2 swapped. P2096 Honda P2096 typically points to a failing downstream O2 sensor biasing lean. P2097 Contaminated or aged downstream O2 sensor reads falsely rich. P2414 Check exhaust manifold for cracks at the collector -- Honda K24 manifolds crack at 100k+ miles and throw P2414 as the AFR sensor sees… P2646 Honda K-series P2646: VTEC solenoid oil screen clogged. P2646 Low oil or wrong-viscosity oil prevents the VTEC rocker actuator from engaging. P3187 P3187 fuel system performance Bank 2 on Honda V6 engines typically indicates a failing VCM (Variable Cylinder Management) system or a… U1206 U1206 lost comm with immobilizer/key module on Honda typically means the transponder key isn't being read. U1207 Accord and TL set U1207 when the driver's door control unit loses communication, usually from fatigued wires in the door jamb.
Frequently Asked Questions
What are the most common check engine light codes on a Honda Accord?
The most commonly reported OBD-II codes for the Honda Accord include B0081, C1651, C1762, C2221, C2309. Each code indicates a specific issue -- tap any code above for the full diagnostic breakdown.
How much does it cost to fix a check engine light on a Honda Accord?
Repair costs vary by code. Many Honda Accord fixes like gas cap replacement, sensor cleaning, or spark plug changes are under $50 in parts and can be done at home. More complex repairs like catalytic converter or transmission work can run $500-$2,000+ at a shop.
Can I drive my Honda Accord with the check engine light on?
It depends on the code. A steady check engine light usually means you can drive short distances safely. A flashing check engine light means stop driving immediately -- continued driving can cause serious engine damage. Scan the code first to know what you are dealing with.