Understanding Acura OBD1 Codes: Symptoms, Causes, and Fixes
If you own an Acura vehicle from the following models – Integra 1.7 1992-1993, Integra 1.8 (includes VTEC) 1992-2006, Legend 1991-1995, MDX 2000-2006, NSX 1991-2006, RSX 2000-2006, SLX 1996-2006, Vigor 1992-1994, 2.2 CL to 3.2 CL 1997-2006, or 2.5 to 3.2 TL 1995-2006 – and you’re experiencing issues with it, the onboard diagnostic system can help you diagnose the problem. Acura OBD1 DTC codes are used to identify the specific issue that your car is experiencing. This complete list of Acura OBD1 DTC codes will help you identify and troubleshoot any problems you may have with your vehicle.
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ACURA OBD1
DTC 0 – Engine Control Module (ECM) Fault
Description: Indicates a problem with the ECM, which controls various engine functions.
Cause: Faulty sensor or wiring issue.
Symptoms: Check Engine Light (CEL) on, decreased engine performance, poor fuel economy.
Location of Fault: Inside the engine compartment, near the battery or firewall.
How to Fix: Check the wiring connections and repair any damaged wiring. Replace the ECM if necessary.
DTC 1: Oxygen Content
Description: Indicates the oxygen sensor is detecting an abnormal amount of oxygen content in the exhaust gas.
Cause: Faulty sensor or wiring issue
Symptoms: CEL on; decreased engine performance; poor fuel economy; rough idling.
Location of Fault: Near the exhaust manifold or catalytic converter
How to Fix: Check the wiring connections and repair any damaged wiring. Replace the oxygen sensor if necessary.
DTC 2: Oxygen Sensor
Description: Indicates a problem with the oxygen sensor, which monitors the amount of oxygen in the exhaust gas.
Cause: Faulty sensor or wiring issue
Symptoms: CEL on; decreased engine performance; poor fuel economy; rough idling.
Location of Fault: Near the exhaust manifold or catalytic converter
How to Fix: Check the wiring connections and repair any damaged wiring. Replace the oxygen sensor if necessary.
DTC 3: Intake Air Temperature
Description: This code indicates a problem with the intake air temperature sensor, which measures the temperature of the air entering the engine.
Cause: Faulty sensor or wiring issue
Symptoms: CEL on; decreased engine performance; poor fuel economy.
Location of Fault: Near the air intake duct or throttle body
How to Fix: Check the wiring connections and repair any damaged wiring. Replace the intake air temperature sensor if necessary.
DTC 4: Crank Angle Sensor
Description: Indicates a problem with the crank angle sensor, which detects the position of the crankshaft.
Cause: Faulty sensor or wiring issue
Symptoms: CEL on; engine may not start or may stall; decreased engine performance.
Location of Fault: Near the crankshaft or harmonic balancer
How to Fix: Check the wiring connections and repair any damaged wiring. Replace the crank angle sensor if necessary.
DTC 5: MAP Sensor
Description: Indicates a problem with the MAP (manifold absolute pressure) sensor, which measures the pressure inside the intake manifold.
Cause: Faulty sensor or wiring issue
Symptoms: CEL on; decreased engine performance; poor fuel economy.
Location of Fault: Near the intake manifold or throttle body
How to Fix: Check the wiring connections and repair any damaged wiring. Replace the MAP sensor if necessary.
DTC 6: Coolant Temperature
Description: Indicates a problem with the coolant temperature sensor, which measures the temperature of the engine coolant.
Cause: Faulty sensor or wiring issue
Symptoms: CEL on; engine may not start or may stall; decreased engine performance; poor fuel economy.
Location of Fault: Near the engine block or thermostat housing
How to Fix: Check the wiring connections and repair any damaged wiring. Replace the coolant temperature sensor if necessary.
DTC 7: Throttle Position Sensor
Description: Indicates a problem with the throttle position sensor, which detects the position of the throttle valve.
Cause: Faulty sensor or wiring issue
Symptoms: CEL on; engine may not start or may stall; decreased engine performance; poor fuel economy; rough idling.
Location of Fault: Near the throttle body
How to Fix: Check the wiring connections and repair any damaged wiring. Replace the throttle position sensor if necessary.
DTC 8 – Top Dead Center (TDC) Position Sensor
Description: Indicates a problem with the TDC position sensor, which detects the position of the No. 1 cylinder.
Cause: Faulty sensor or wiring issue
Symptoms: CEL on; engine may not start or may stall; decreased engine performance; poor fuel economy.
Location of Fault: Near the crankshaft or timing belt cover
How to Fix: Check the wiring connections and repair any damaged wiring. Replace the TDC position sensor if necessary.
DTC 9: No. 1 Cylinder Position Sensor
Description: Indicates a problem with the No. 1 cylinder position sensor, which detects the position of the No. 1 cylinder.
Cause: Faulty sensor or wiring issue
Symptoms: CEL on; engine may not start or may stall; decreased engine performance; poor fuel economy.
Location of Fault: Near the camshaft or timing belt cover
How to Fix: Check the wiring connections and repair any damaged wiring. Replace the No. 1 cylinder position sensor if necessary.
DTC 10: Intake Air Temperature (High)
Description: This code indicates a problem with the intake air temperature sensor, which measures the temperature of the air entering the engine.
Cause: Faulty sensor or wiring issue
Symptoms: CEL on; decreased engine performance; poor fuel economy.
Location of Fault: Near the air intake duct or throttle body
How to Fix: Check the wiring connections and repair any damaged wiring. Replace the intake air temperature sensor if necessary.
DTC 11: Vehicle Speed Sensor
Description: Indicates a problem with the vehicle speed sensor, which detects the speed of the vehicle.
Cause: Faulty sensor or wiring issue
Symptoms: CEL on, inaccurate speedometer readings, transmission shifting problems.
Location of Fault: Near the transmission or differential
How to Fix: Check the wiring connections and repair any damaged wiring. Replace the vehicle speed sensor if necessary.
DTC 12 (EGR Lift Sensor)
Description: Indicates a problem with the EGR (exhaust gas recirculation) lift sensor, which detects the position of the EGR valve.
Cause: Faulty sensor or wiring issue
Symptoms: CEL on; decreased engine performance; poor fuel economy.
Location of Fault: Near the EGR valve
How to Fix: Check the wiring connections and repair any damaged wiring. Replace the EGR lift sensor if necessary.
DTC 13: Barometric Pressure Sensor
Description: Indicates a problem with the barometric pressure sensor, which measures the atmospheric pressure.
Cause: Faulty sensor or wiring issue
Symptoms: CEL on; decreased engine performance; poor fuel economy.
Location of Fault: Near the intake manifold or throttle body
How to Fix: Check the wiring connections and repair any damaged wiring. Replace the barometric pressure sensor if necessary.
DTC 14: Idle Air Control Valve (IACV)
Description: Indicates a problem with the IACV, which controls the idle speed of the engine.
Cause: Faulty valve or wiring issue
Symptoms: CEL on, engine idling too high or too low, decreased engine performance, poor fuel economy
Location of Fault: Near the throttle body
How to Fix: Check the wiring connections and repair any damaged wiring. Replace the IACV if necessary.
DTC 15: Ignition Output Signal
Description: Indicates a problem with the ignition output signal, which controls the ignition timing of the engine.
Cause: Faulty sensor or wiring issue
Symptoms: CEL on; engine may not start or may stall; decreased engine performance; poor fuel economy.
Location of Fault: Near the distributor or ignition coil
How to Fix: Check the wiring connections and repair any damaged wiring. Replace the ignition output signal sensor if necessary.
DTC 16: Fuel Injector
Description: This code indicates a problem with the fuel injector, which delivers fuel to the engine.
Cause: Faulty injector or wiring issue
Symptoms: CEL on, engine misfiring, decreased engine performance, poor fuel economy
Location of the fault: Near the fuel rail
How to Fix: Check the wiring connections and repair any damaged wiring. Replace the fuel injector if necessary.
DTC 17: Vehicle Speed Sensor (VSS)
Description: Indicates a problem with the vehicle speed sensor, which detects the speed of the vehicle.
Cause: Faulty sensor or wiring issue
Symptoms: CEL on, inaccurate speedometer readings, transmission shifting problems.
Location of Fault: Near the transmission or differential
How to Fix: Check the wiring connections and repair any damaged wiring. Replace the vehicle speed sensor if necessary.
DTC 20: Electrical Load Detector (ELD)
Description: Indicates a problem with the ELD, which monitors the electrical load on the alternator.
Cause: Faulty sensor or wiring issue
Symptoms: CEL on; battery not charging properly; electrical system malfunctions.
Location of Fault: Near the battery or alternator
How to Fix: Check the wiring connections and repair any damaged wiring. Replace the ELD if necessary.
DTC 21 – VTEC Solenoid Valve
Description: Indicates a problem with the VTEC (variable valve timing and lift electronic control) solenoid valve, which controls the operation of the VTEC system.
Cause: Faulty valve or wiring issue
Symptoms: CEL on; decreased engine performance; poor fuel economy.
Location of Fault: Near the cylinder head or camshaft
How to Fix: Check the wiring connections and repair any damaged wiring. Replace the VTEC solenoid valve if necessary.
DTC 22: VTEC Pressure Valve
Description: Indicates a problem with the VTEC pressure valve, which controls the oil pressure of the VTEC system.
Cause: Faulty valve or wiring issue
Symptoms: CEL on; decreased engine performance; poor fuel economy.
Location of Fault: Near the cylinder head or camshaft
How to Fix: Check the wiring connections and repair any damaged wiring. Replace the VTEC pressure valve if necessary.
DTC 23: Knock Sensor
Description: Indicates a problem with the knock sensor, which detects engine knocking.
Cause: Faulty sensor or wiring issue
Symptoms: CEL on; decreased engine performance; poor fuel economy.
Location of Fault: Near the cylinder block or cylinder head
How to Fix: Check the wiring connections and repair any damaged wiring. Replace the knock sensor if necessary.
DTC 30 (Automatic Transmission)
Description: Indicates a problem with the automatic transmission.
Cause: Transmission fluid level, transmission solenoid or wiring issue, mechanical failure.
Symptoms: CEL on, transmission shifting problems, decreased engine performance.
Location of Fault: inside the transmission or near the transmission
How to fix: Check the transmission fluid level and condition. Check the wiring connections and repair any damaged wiring. Replace the transmission solenoid or mechanical components if necessary.
DTC 41: Primary Oxygen Sensor (O2S)
Description: Indicates a problem with the primary oxygen sensor, which measures the oxygen content in the exhaust gas.
Cause: Faulty sensor or wiring issue
Symptoms: CEL on; decreased engine performance; poor fuel economy.
Location of Fault: Near the exhaust manifold or catalytic converter
How to Fix: Check the wiring connections and repair any damaged wiring. Replace the primary oxygen sensor if necessary.
DTC 43: Fuel Supply System
Description: Indicates a problem with the fuel supply system.
Cause: Fuel pump or fuel filter issue; clogged fuel injectors
Symptoms: CEL on, engine misfiring, decreased engine performance, poor fuel economy.
Location of Fault: Near the fuel pump or fuel filter
How to fix: Check the fuel pump and fuel filter for proper function. Clean or replace clogged fuel injectors if necessary.
DTC 45: System Too Rich or Too Lean
Description: This code indicates a problem with the air/fuel ratio of the engine.
Cause: Faulty oxygen sensors, fuel pressure regulator issues, and clogged fuel injectors
Symptoms: CEL on, engine misfiring, decreased engine performance, poor fuel economy
Location of Fault: Near the oxygen sensor, fuel pressure regulator, or fuel injectors
How to fix: Check the oxygen sensor for proper function. Check the fuel pressure regulator and fuel injectors for clogs or damage. Replace any faulty components if necessary.
DTC 48, Primary Fuel Injector
Description: This code indicates a problem with the primary fuel injector, which delivers fuel to the engine.
Cause: Faulty injector or wiring issue
Symptoms: CEL on, engine misfiring, decreased engine performance, poor fuel economy
Location of the fault: Near the fuel rail
How to Fix: Check the wiring connections and repair any damaged wiring. Replace the primary fuel injector if necessary.
DTC 61: Oxygen Sensor (Secondary)
Description: Indicates a problem with the secondary oxygen sensor, which measures the oxygen content in the exhaust gas downstream of the catalytic converter.
Cause: Faulty sensor or wiring issue
Symptoms: CEL on; decreased engine performance; poor fuel economy.
Location of Fault: Near the catalytic converter
How to Fix: Check the wiring connections and repair any damaged wiring. Replace the secondary oxygen sensor if necessary.
DTC 63: Secondary Oxygen Sensor
Description: Indicates a problem with the secondary oxygen sensor, which measures the oxygen content in the exhaust gas downstream of the catalytic converter.
Cause: Faulty sensor or wiring issue
Symptoms: CEL on; decreased engine performance; poor fuel economy.
Location of Fault: Near the catalytic converter
How to Fix: Check the wiring connections and repair any damaged wiring. Replace the secondary oxygen sensor if necessary.
DTC 65: Automatic Transmission
Description: Indicates a problem with the automatic transmission.
Cause: Transmission fluid level, transmission solenoid or wiring issue, mechanical failure.
Symptoms: CEL on, transmission shifting problems, decreased engine performance.
Location of Fault: inside the transmission or near the transmission
How to fix: Check the transmission fluid level and condition. Check the wiring connections and repair any damaged wiring. Replace the transmission solenoid or mechanical components if necessary.
DTC 67, Catalyst System
Description: This code indicates a problem with the catalytic converter.
Cause: faulty converter or wiring issue.
Symptoms: CEL on; decreased engine performance; poor fuel economy.
Location of Fault: Near the catalytic converter
How to Fix: Check the wiring connections and repair any damaged wiring. Replace the catalytic converter if necessary.
DTC 70: Automatic Transmission
Description: Indicates a problem with the automatic transmission.
Cause: Transmission fluid level, transmission solenoid or wiring issue, mechanical failure.
Symptoms: CEL on, transmission shifting problems, decreased engine performance.
Location of Fault: inside the transmission or near the transmission
How to fix: Check the transmission fluid level and condition. Check the wiring connections and repair any damaged wiring. Replace the transmission solenoid or mechanical components if necessary.
DTC 71, Random Misfire
Description: Indicates a problem with multiple cylinders misfiring randomly.
Cause: Faulty spark plugs or wires; fuel injector issue; vacuum leak
Symptoms: CEL on, engine misfiring, decreased engine performance, poor fuel economy
Location of fault: throughout the engine
How to fix: Check and replace faulty spark plugs or wires. Check the fuel injectors and clean or replace them if necessary. Check for vacuum leaks and repair any damaged vacuum hoses.
DTC 72, Cylinder 1 Misfire
Description: Indicates a problem with cylinder 1 misfiring.
Cause: Faulty spark plug or wire; fuel injector issue; vacuum leak
Symptoms: CEL on, engine misfiring, decreased engine performance, poor fuel economy
Location of Fault: Cylinder 1.
How to Fix: Check and replace the faulty spark plug or wire for cylinder 1. Check the fuel injector and clean or replace it if necessary. Check for vacuum leaks and repair any damaged vacuum hoses.
DTC 73, Cylinder 2 Misfire
Description: Indicates a problem with cylinder 2 misfiring.
Cause: Faulty spark plug or wire; fuel injector issue; vacuum leak
Symptoms: CEL on, engine misfiring, decreased engine performance, poor fuel economy
Location of Fault: Cylinder 2.
How to Fix: Check and replace the faulty spark plug or wire for cylinder 2. Check the fuel injector and clean or replace it if necessary. Check for vacuum leaks and repair any damaged vacuum hoses.
DTC 74: Cylinder 3 Misfire
Description: Indicates a problem with cylinder 3 misfiring.
Cause: Faulty spark plug or wire; fuel injector issue; vacuum leak
Symptoms: CEL on, engine misfiring, decreased engine performance, poor fuel economy
Location of Fault: Cylinder 3.
How to Fix: Check and replace the faulty spark plug or wire for cylinder 3. Check the fuel injector and clean or replace it if necessary. Check for vacuum leaks and repair any damaged vacuum hoses.
DTC 75: Cylinder 4 Misfire
Description: Indicates a problem with cylinder 4 misfiring.
Cause: Faulty spark plug or wire; fuel injector issue; vacuum leak
Symptoms: CEL on, engine misfiring, decreased engine performance, poor fuel economy
Location of Fault: Cylinder 4.
How to Fix: Check and replace the faulty spark plug or wire for cylinder 4. Check the fuel injector and clean or replace it if necessary. Check for vacuum leaks and repair any damaged vacuum hoses.
DTC 80: Exhaust Gas Recirculation (EGR) System
Description: Indicates a problem with the EGR system, which recirculates exhaust gas back into the engine to reduce emissions.
Cause: Faulty EGR valve or wiring issue
Symptoms: CEL on, decreased engine performance, poor fuel economy, rough idle
Location of Fault: Near the intake manifold or EGR valve
How to Fix: Check the wiring connections and repair any damaged wiring. Replace the EGR valve if necessary.
DTC 86: Engine Coolant Temperature (ECT) Sensor
Description: Indicates a problem with the ECT sensor, which monitors the engine coolant temperature.
Cause: Faulty sensor or wiring issue
Symptoms: CEL on; inaccurate temperature gauge reading; poor fuel economy; rough idle.
Location of Fault: Near the engine coolant inlet or thermostat
How to Fix: Check the wiring connections and repair any damaged wiring. Replace the ECT sensor if necessary.
DTC 90, Evaporative Emission Control System
Description: Indicates a problem with the evaporative emission control system, which prevents the release of fuel vapors into the atmosphere.
Cause: Faulty canister or wiring issue.
Symptoms: CEL on, fuel odor, decreased engine performance.
Location of Fault: Near the fuel tank or charcoal canister
How to Fix: Check the wiring connections and repair any damaged wiring. Replace the charcoal canister if necessary.
DTC 91: Fuel Tank Pressure Control System
Description: Indicates a problem with the fuel tank pressure control system, which monitors the pressure inside the fuel tank.
Cause: Faulty pressure sensor or wiring issue
Symptoms: CEL on, fuel odor, decreased engine performance.
Location of Fault: Near the fuel tank or pressure sensor
How to Fix: Check the wiring connections and repair any damaged wiring. Replace the pressure sensor if necessary.
DTC 92: Evaporative Emission Control System (Low Purge Flow)
Description: Indicates a problem with the evaporative emission control system, specifically a low purge flow.
Cause: Faulty canister or wiring issue.
Symptoms: CEL on, fuel odor, decreased engine performance.
Location of Fault: Near the fuel tank or charcoal canister
How to Fix: Check the wiring connections and repair any damaged wiring. Replace the charcoal canister if necessary.
DTC 93: Evaporative Emission Control System (High Purge Flow)
Description: Indicates a problem with the evaporative emission control system, specifically a high purge flow.
Cause: Faulty canister or wiring issue.
Symptoms: CEL on, fuel odor, decreased engine performance.
Location of Fault: Near the fuel tank or charcoal canister
How to Fix: Check the wiring connections and repair any damaged wiring. Replace the charcoal canister if necessary.
DTC 94, Fuel Line Restriction
Description: Indicates a problem with a restriction in the fuel line, causing inadequate fuel flow to the engine.
Cause: Clogged fuel filter; kinked or damaged fuel line; faulty fuel pressure regulator.
Symptoms: CEL on, engine misfiring, decreased engine performance, poor fuel economy
Location of Fault: Near the fuel filter or fuel line
How to Fix: Check the fuel filter and replace if necessary. Check the fuel line for any kinks or damage and repair if necessary. Replace the fuel pressure regulator if necessary.
DTC 95: Fuel Pressure Regulator Control Solenoid Valve
Description: Indicates a problem with the fuel pressure regulator control solenoid valve, which controls fuel pressure in the fuel rail.
Cause: Faulty solenoid valve or wiring issue
Symptoms: CEL on; decreased engine performance; poor fuel economy.
Location of Fault: Near the fuel pressure regulator or fuel rail
How to Fix: Check the wiring connections and repair any damaged wiring. Replace the solenoid valve if necessary.
DTC 96: Fuel Pressure Malfunction
Description: Indicates a problem with the fuel pressure in the fuel rail.
Cause: Faulty fuel pump or wiring issue; clogged fuel filter; faulty fuel pressure regulator.
Symptoms: CEL on; decreased engine performance; poor fuel economy.
Location of Fault: Near the fuel pump, fuel filter, or fuel pressure regulator.
How to Fix: Check the wiring connections and repair any damaged wiring. Check the fuel pump for proper function. Replace the fuel filter or fuel pressure regulator if necessary.
DTC 97: Shift Control Solenoid Valve A/B Malfunction
Description: Indicates a problem with the shift control solenoid valve A/B, which controls the shifting of the automatic transmission.
Cause: Faulty solenoid valve or wiring issue
Symptoms: CEL on, transmission shifting problems, decreased engine performance.
Location of Fault: inside the automatic transmission or near the transmission.
How to Fix: Check the wiring connections and repair any damaged wiring. Replace the shift control solenoid valve A/B if necessary.
WORDS FROM ERWIN SALARDA
By having a complete understanding of Acura OBD1 DTC codes, you’ll be better equipped to diagnose and fix issues with your vehicle. Remember to always follow proper safety procedures and seek professional assistance if needed. With this complete list of Acura OBD1 DTC codes, you’ll have the knowledge to quickly identify any issues with your Acura and take the necessary steps to get it running smoothly again.