The lamps are numbered in a Binary fashion - to work out what code the ECU is displaying, add up the corresponding number for each LED.

Lamp Numbering
8	4	2	1
0	0	1	1

0 = Lamp off
1 = Lamp on

The combination above shows Fault 3 - 1+2=3.

CEL = Check engine lamp (in instrument cluster)

No	Pattern				CEL	Failure attributable to	Symptom
0	0	0	0	0	1	Control Unit. Short-circuit in meter.	Engine cannot be started. No noticeable symptom.
3	0	0	1	1	0	MAP Sensor. Defective circuit or unplugged / defective sensor.	Poor engine response. Idle speed lowers. Engine tends to stall.
5	0	1	0	1	0	Disconnected MAP sensor vacuum tube.	Engine runs very rich. Idle speed lowers. Engine tends to stall.
6	0	1	1	0	0	Coolant temperature sensor. Defective circuit or unplugged / defective sensor.	Difficult to start from cold. Poor engine response. Problems starting.
7	0	1	1	1	0	Throttle position sensor. Defective circuit or unplugged / defective sensor.	Poor throttle response. Problems starting from cold.
8	1	0	0	0	0	TDC Sensor (in distributor). Defective circuit or unplugged / defective sensor.	Irregular idle speed. Poor response. Engine will not start.
9	1	0	0	1	0	CYL Sensor (in distributor). Defective circuit or unplugged / defective sensor.	Irregular idle speed. Poor response. Engine will not start.
10	1	0	1	0	1	Air temperature sensor. Defective circuit or unplugged / defective sensor.	Irregular idle speed when cold.
11	1	0	1	1	1	IMA Sensor (idle mix adjust). Defective circuit or unplugged / defective sensor.	Emissions problems.
13	1	1	0	1	1	PA Sesnor (atmospheric pressure. Defective circuit or unplugged / defective sensor.	Poor performance at high altitude.

This table is an edited version of Honda's original. Notice that the numbers corresponding to each error are also tie up with the main fault code list here.