ecu light

[REK13S]

some times when i drive the ecu lights comes on n stays on until i turn off the engine anybody know wots wrong or do i have to drive 2 hanny's for them to check it out

[wynode]

Check your ECU for error codes. And then take it from there.

[SiNH]

some times when i drive the ecu lights comes on n stays on until i turn off the engine anybody know wots wrong or do i have to drive 2 hanny's for them to check it out

You gotta give more info bro.

This is what someone wrote in the Teamevade forum:

i got a family car right and like
everytime me or my dad drives the car... and like say
eg. we go down hill and take my foot off the gas.. and the revs... go down to about 1, 250RPM and the speed is about between 40 - 60 km/h the car flashes CHECK ENGINE
anyone know why or some problems??

And this is my reply:

I had that problem before.

Its the O2 sensor dying or dead.

When you are cruising with light throddle or foot off the pedal it is in close loop mode.

The ECU at this stage uses the O2 sensor to determine the air/fuel mixture, and if your sensor is dead then it will give you this light, however if you hammer the car or drive it in and out of traffic the light wont come on since its no longer in close loop mode.

So, when does your light come on? as soon as you start the engine? Does your speedo needle moves erractically? I mean like does it shake continuously and the speed climbs? Is it the same scenario as the guy from TE? Its an AUTO right?

[Redteg]

I have read that the check engine light comes on if there is a problem within the emmissions system. Used to happen to me now and then; it was the oxygen sensor.
I know with my teg there is a way of checking the ECU for error codes, but i'd imagine its different for different models, as would be the error codes themselves.

Basically, for my teg you reset the ECU by either disconnecting the battery or pulling a fuse, then you turn the key to the 'on' position and watch the ECU light for 'Long' and "Short' flashes, which relate to a number and code. Some cars need jumping of a particular plug... the light is on the ecu itself

I have a workshop manual with troubleshooting flow diagrams for the teg. I've always sorted out my problems like that, but i dunno if you can source it for your car.

After all that, it does sound easier to just take to Hanny's :)

[wynode]

I'm with SiNH.

If the car is working fine apart from that, then it is most probably the 02 sensor, but we need more info.

Checking the ECU error codes is a good way of finding exactly what the problem is.

[BLKCRX]

ECU problems codes are diagnostic outputs from the ECU, used to indicate in what area a problem lies. Usually the check engine warning light (on the dash) will come on for a serious problem, but will not necessarily come on for a minor problem. The ECU will remember problem codes with the ignition off; the only way to clear the codes is to disconnect the battery or remove the hazard fuse for half a minute or so.


Pre OBDI ECUs
To read the codes, turn the ignition on and look at the LED inside the ECU. The LED is visible through a small plastic window in the top of the ECU. The ECU can signal simultaneous problems by blinking separate codes, one after the other. Problem codes 1 - 9 are indicated by 1 - 9 flashes, problem codes over 9 use one long flash as ten short flashes.

OBDI and later ECUs
Find the diagnostic connector, which is a two wire blue connector found near the passengers feet, or in the centre console.
Short out the diagnostic connector with a piece of wire. The check engine light on the dash will flash the problem codes.


Code Meaning
1 O2A - Oxygen sensor #1
2 O2B - Oxygen sensor #2
3 MAP - manifold absolute pressure sensor
4 CKP - crank position sensor
5 MAP - manifold absolute pressure sensor
6 ECT - water temperature sensor
7 TPS - throttle position sensor
8 TDC - top dead centre sensor
9 CYP - cylinder sensor
10 IAT - intake air temperature sensor
12 EGR - exhaust gas recirculation lift valve
13 BARO - atmospheric pressure sensor
14 IAC (EACV) - idle air control valve
15 Ignition output signal
16 Fuel injectors
17 VSS - speed sensor
19 Automatic transmission lockup control valve
20 Electrical load detector
21 VTEC spool solenoid valve
22 VTEC pressure valve
23 Knock sensor
30 Automatic transmission A signal
31 Automatic transmission B signal
41 Primary oxygen sensor heater
43 Fuel supply system
45 Fuel system too rich or lean
48 LAF - lean air fuel sensor
54 CKF - crank fluctuation sensor
58 TDC sensor #2
61 Primary oxygen sensor
63 Secondary oxygen sensor
65 Secondary oxygen sensor heater

http://www.hondata.com/images/ecucodes.gif

[Redteg]

Thats what I remember :)

This is useful info for all!

[wynode]

Thanks for that James. I will put a link in the sticky.