HOW TO: Read Check Engine Light
Posted: Thu Jun 16, 2022 12:14 pm
When the computer (ECU) in your car detects a problem with how the car is running it reports it by lighting up the yellow engine light on your dash. Any Joe Schmoe can actually check what the ECU is complaining about as long as they know how.
Service Connector:
In order to get the code you'll need to find the service connector. On the 5th Gens it's on the right hand side of the centre console underneath a carpeted panel that just pops right out. The connector looks like a telephone connector and is plugged into a blue plastic piece that just serves as a holder. Unplug it and you'll see that it has two sockets in it that lead to two wires.
Getting the Code:
You'll need a small piece of wire for this. Make sure the car is off. Just connect the two ports in the service connector together with the wire. After you've shorted the service connector, turn the key in the ignition to the on position (you don't actually need to start the car) and the yellow engine light will flash at you. There will be a series of long flashes, short flashes, and then it will repeat itself. Count the number of long flashes and short flashes and this will give you the MIL code. 2 long flashes and 3 short flashes is code 23. Once you've found the code, turn the key back to off and remove the wire from the service connector. You can look up the code in the following table.
MIL Codes:
Service Connector:
In order to get the code you'll need to find the service connector. On the 5th Gens it's on the right hand side of the centre console underneath a carpeted panel that just pops right out. The connector looks like a telephone connector and is plugged into a blue plastic piece that just serves as a holder. Unplug it and you'll see that it has two sockets in it that lead to two wires.
Getting the Code:
You'll need a small piece of wire for this. Make sure the car is off. Just connect the two ports in the service connector together with the wire. After you've shorted the service connector, turn the key in the ignition to the on position (you don't actually need to start the car) and the yellow engine light will flash at you. There will be a series of long flashes, short flashes, and then it will repeat itself. Count the number of long flashes and short flashes and this will give you the MIL code. 2 long flashes and 3 short flashes is code 23. Once you've found the code, turn the key back to off and remove the wire from the service connector. You can look up the code in the following table.
MIL Codes:
| Codes | Detection Item | Probable Cause |
|---|---|---|
3 |
Manifold Absolute Pressure Signal
|
|
10 |
Intake Air Temperature Circuit
|
|
86 |
Engine Coolant Temperature Circuit
|
|
6 |
Engine Coolant Temperature Circuit
|
|
7 |
Throttle Position Circuit
|
|
1 |
Primary Heated Oxygen Circuit
|
|
61 |
Primary Heated Oxygen Circuit
|
|
41 |
Primary Heated Oxygen Circuit
|
|
63 |
Secondary Heated Oxygen Circuit
|
|
65 |
Secondary Heated Oxygen Circuit
|
|
45 |
System too Rich/Lean |
|
71,72,73,74 |
Misfire Detected
|
|
23 |
Knock Sensor Circuit Malfunction |
|
4 |
Crankshaft Position Sensor Circuit
|
|
80 |
Exhaust Gas Recirculation
|
|
67 |
Catalyst System Efficiency Below Threshold |
|
92 |
Evaporative Emission Control System
|
|
91 |
Fuel Tank Pressure Sensor High/Low Input |
|
17 |
Vehicle Speed Circuit Malfunction |
|
14 |
Idle Control System Malfunction |
|
70 |
Automatic Transaxle |
|
13 |
Barometric Pressure Circuit
|
|
5 |
Manifold Absolute Pressure
|
|
22 |
VTEC System Malfunction |
|
20 |
Electrical Load Detector Circuit
|
|
8 |
Crankshaft Position / Top Dead Center Sensor
|
|
9 |
Cylinder Position Sensor
|
|
90 |
Evaporative Emission Control System
|
|
92 |
Evaporative Emission Purge Flow Switch
|
|
12 |
EGR Valve Lift Sensor
|
|
14 |
Idle Air Control Valve Circuit Failure |
|
30 |
SEAF/SEFA Signal Line Failure |
Open or short in SEAF/SEFA circuit |