ACURA

  Retreiving codes:
The Engine Control Unit (ECU) stores the codes which are accessed by reading the flashing light emitting diode (LED) on the unit (early models) or the check engine light on the dash for later models.
If the ECU has two LED's, the red one is for codes. On OBD-II models, the check engine light is referred to as malfunction indicator light (MIL).

  Where is the ECU located you may ask?

The ECU on 1990 and earlier Legend sedans and Integra models through 1989 is located under the front passenger seat.

On Legend coupes, 1991 and later Legend sedans, 1990 through 1994 Integras and all Vigor models, the ECU is found under the dashboard on the passenger's side behind the carpet; 1990 Legends incorporate a flip-out mirror so the LED can be seen. On 1995 through 1999 Integra models, the ECM is located behind the right kick panel.

On 1997 2.2CL models, 1998 and 1999 2.3CL models, 1995 through 1999 2.5TL models, 1997-1999 3.0CL models, 1996-1998 3.2TL models and 1996-1999 3.5RL models, the ECM is located below the right ( passenger side ) front footrest.

On 1996-1999 SLX models and 1999 3.2TL models, the PCM is located behind the center of the dash, below the radio.
    
 How to access the codes:

1990 and earlier Legend, 1991 and earlier Integra:
When the ECU sets a code, the check engine light on the dashboard will illuminate. To access the codes, turn the ignition switch on, then count the number of times the LED flashes.
On 1986-1989 models, the light will blink a sequence the total representing the code number, for example: 14 short blinks indicates code 14.
1990 Legends and 1990-1991 Integras, the light will hold a longer blink to represent the first digit of a two digit number followed by short blinks indicating the second digit, for example: 1 long blink followed by 8 short blinks indicates code 18, if there is more than one engine trouble code stored in the ECM, the codes will display in sequence, there will be a pause, and the codes will repeat.
On 1991 and later Legend and all 1992 and later models, locate the two terminal diagnostic connector. On Legend and Integra models the terminal is located under the right side of the dash, behind the glove compartment, on Vigor models it is located behind the right side of the center console, under the dash. On all other models it is located under the left side of the dash; Turn the ignition switch on, bridge the two terminals of the diagnostic connector with a jumper wire, any store codes will be displayed by the check engine light on the dash in a series of flashes, for example: a code 14 will be displayed by a long flash followed by 4 short flashes, if there is more than one code stored in the ECU, there will be a pause after the first code has been displayed, folloew by the second code.

  Take note that several vehicles equipped with OBD II will require a scan tool to access the engine trouble codes, you will know if  your vehicle requires you to use such tool if you find a OBD II diagnostic connector on the driver's side  under the dashboard.
 

      How to clear the codes:

On 1990 and earlier Legend, 1991 and later Integra remove the hazzard fuse at the battery positive terminal ( Integra ) or the alternator sense fuse located under the hood in the relay box ( Legend) for at least 10 seconds.
1991 and later Legend and all 1992 and later models remove the back-up fuse from the relay box under the hood ( Integra,Vigor) or the ACG fuse from the fuse box under the left side of the dash ( Legend ) for at least 10 seconds. On all other models, erase the codes by removing the ECM fuse from the under dash fuse panel.

  Code definitions:

   1- Oxygen sensor or circuit ( Integra) ; left or front oxygen sensor (V6 engine)
   2- Left or rear oxygen sensor ( V6 engine )
   3- Manifold absolute pressure (MAP) sensor or circuit
   4- Crank position sensor No. 1
   5- Manifold absolute pressure (MAP)sensor or circuit
   6- Coolant temperature sensor or circuit
   7- Throttle position sensor or circuit
   8- TDC sensor or circuit (Integra)
   9- Crankshaft position sensor or circuit
 10- Intake air temperature sensor or circuit
 12- EGR control system
 13- Barometric pressure sensor or circuit
 14- Idle air control system
 15- Ignition output signal
 16- Fuel injector
 17- Vehicle speed sensor or circuit
 18- Ignition timing adjustment
 19- Lock-up control solenoid valve
 20- Electric load
 21- Front VTEC solenoid valve (NSX), front spool solenoid valve (some models)
 22- Front VTEC pressure switch NSX), front valve timing oil pressure switch (some models)
 23- Front knock sensor ( some NSX, Vigor)
 30- A/T FI signal A
 31- A/T FI signal B
 35 TC standby signal
 36- TC FC signal
 41- Oxygen sensor heater ( Integra), front oxygen sensor heater
 42- Rear oxygen sensor heater ( Legend, 3.0L)
 43- Fuel supply system ( 4 cylinder models), front fuel supply systems ( V-6 models)
 44- Rear fuel supply system ( V-6 models)
 45- Front fuel metering system
 46- Rear fuel metering system
 47- Fuel pump
 50- Mass Air Flow sensor
 51- Rear spool solenoid valve ( Legend), rear VTEC solenoid valve ( other models)
 52- Rear valve timing oil pressure switch ( Legend), rear VTEC pressure switch ( other models)
 53- Rear knock sensor
 54- Crank position sensor
 59- No. 1 cylinder position
 61- Upstream oxygen sensor, slow response
 63- Downstream oxygen sensor, slow response
 65- Downstream oxygen sensor heater
 67- Low catalytic converter efficiency
 70- Transaxle
 71- Misfire, cylinder no. 1
 72- Misfire, cylinder no. 2
 73- Misfire, cylinder no. 3
 74- Misfire, cylinder no. 4
 75- Misfire, cylinder no. 5
 76- Misfire, cylinder no. 6, Random misfire ( all models except V-6 engines)
 79- Spark plug voltage detection circuit
 80- Low EGR flow
 86- Coolant temperature sensor out of range
 90- EVAP system leak
 92- EVAP purge control solenoid.