Getting Check Engine Light (CEL) Codes

Fifth Generation Honda Prelude topics

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Joined: Fri Nov 11, 2005 2:55 am
Prelude Model: 1991 SE-SR
Location: Alberta, Canada

Getting Check Engine Light (CEL) Codes

Post by spiffyguido »

Hey everyone,

I thought I would quickly put together a quick how-to for you 5th generation owners on how to get trouble codes from your ECU.

When the ECU in your car detects that your car isn't running as it should, it reports this to you by lighting the yellow engine light on your dash. You don't have to take the car to the dealer to get the code; you can do it yourself.

Locating the Service Connector

To get the code, you first need to locate the ECU's service connector in your vehicle. On a 5th generation Prelude, the service connector is located down the right side of the center console in the passenger side footwell. If you look, you'll find a carpeted panel that pops out. Behind the panel is a connector that looks like a telephone connector. It will be plugged into a blue holder. Unplug it from the blue holder. The connector should have two female sockets.

Getting the CEL Code

Now that you have the connector exposed, with the car off, use a small piece of wire to connect the two ports of the connector, effectively shorting it out. Turn the ignition to the 'on' position and get ready to count the flashes of your check engine light. The check engine light will report codes to you, followed by a long pause in between each one. The sequence will then repeat.

To understand what the flashes mean, remember that a long flash stands for 10, and a short flash stands for a 1. For example, 2 long flashes followed by 7 short flashes would stand for code 27.

Once you're done getting the code, turn the key off, plug the connector back into the blue connector and replace the panel.

CEL Code Guide

Here is what the different check engine codes mean:

0-Engine Control Module (ECM)
1- Heated Oxygen Sensor (HO2S)
3- Manifold Absolute Pressure (MAP Sensor)
4- Cranshaft Position (CKP Sensor)
5- Manifold Absolute Pressure (MAP Sensor)
6- Engine Coolant Temperature (ECT Sensor)
7- Throttle Position (TP Sensor)
8- Top Dead Center Position (TDC Sensor)
9- No. 1 Cylinder Position (CYP Sensor)
10- Intake Air Temperature (IAT Sensor)
12- Exhaust Gas Recirculation ( EGR Valve Lift Sensor)
13- Barometric Pressure ( BARO Sensor)
14- Idle Air Control ( IAC Valve)
15- Ignition Output Signal
16- Fuel Injector
17- Vehicle Speed Sensor (VSS)
20- Electrical Load Detector (ELD)
21- Variable Valve Timing & Valve Lift Electronic Control (VTEC) Solenoid Valve
22-Variable Valve Timing & Valve Lift Electronic Control (VTEC) Pressure Swtich
23- Knock Sensor (KS) *Except F22 engines*
41- Heated Oxygen Sensor (HO2S) Heater
43- Fuel Supply System


Sir Kyle
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Location: Bend, OR

Post by Sir Kyle »

Oh cool I was wondering how this was done. It's like $60 just to get a CEL checked. At least thats what it was for my tundra. Good info man, Thanks.
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