2000 Lanos 1.6 high idle when warm + engine control light

[hugoboss]

hi all
total newbie here be gentle pls

2000 Lanos 1.6sx (South Africa). Starts and idles normally till normal operating temp.
After running hot for a while (extended driving) the engine control light illuminates and stays on, as well as the idling is very high at that stage. Once the car has "cooled down" the idling returns to normal.

I looked for the ALDL in the engine compartment but can't see one, checked under passenger dash, looks like a connector is there, but it's the newer ODBII? version I suspect.
Can someone mbe post a pic of where to find the ECU and what they look like?

Is there a NON GO TO THE DEALER way to activate and check the ECU for symptons pls?

TIA and happy Woo'ing

[Trey05Woo]

The car uses an OBDII connector. You need a compliant scan tool or code reader. A scan tool which displays engine data is preferred.

The connector is located under the dash on the front left of the center console (lhd vehicle).

Get one put on and get the trouble code.

[MMamdouh]

OBD port is located in one of two locations on a lanos

1- under the glove box compartment
2- at the back side of the dash at the area of the cassette and facing the driver (LHD)

MMamdouh

[hugoboss]

thanks guys, found the connector. Under the dash (lh side of vehicle as we are r/h drive here)

Took it to a GM Dealer this morning, they didn't have the scanner - go figger.
Across the road was a service center that had a generic scanner, guy tried to plug it in using OBDII, wrong connector.
Good thing he had the GM/Daewoo connector (OBDI???) but he was unable to determine the exact model for reading from the list of vehicles (it was a Hanatech reader if I remember correctly)
Anyhoo, long story short, he was able to communicate with the ECU at some point and seemed to isolate the fault to the Idle Sensor thingie.

He advised to remove it and Q-20 it (oil spray lube) and refit and check. I did that. Before I removed and fixed the idling was regular at 1550rpm, and after replacing, it jumped to 2300rpm.
ps. I mentioned the idling only picks ups when the car is warm, was fed wrong info (my daughters' car).
The idling is high from start and stays there. The Engine control light is erratic.

I bought a new idle control valve/unit? and replaced. Idling stayed exactly the same @ 2300rpm.

Now I have no idea what next to do to get the darn idling to come back to earth, any ideas there please?
I did check all the hoses etc for air leaks (as this is what the guy said too, it's sucking excessive air somewhere?)

Would apprecaite any assistances here.

Thanks much for your help so far.

[Trey05Woo]

Check the rubber boots which run from the throttle body to the purge valve mounted at the rear of the engine, on the intake manifold support bracket. This is the place most Daewoos seem to suffer from vaccum leaks.

Check the EGR feeds at the rear of the intake manifold. These tiny oval gaskets get burned out with age, and you will develop a MAJOR vaccum leak at these connections, - another common place 1.6l develop vaccum leaks.

Check the throttle body mounting gasket. If the car consumes oil the oil build up at the throttle body valve will eventually damage the gasket.

Check for leaks at both intake ports the upper and lower ports.

Vaccum leaks are easily detected by spraying starting fluid or similar in the vincinity of the leak. If present, it will affect engine speed. (either raise or stumble).

You need to make sure you do not have a TPS votlage fault.Too high TPS voltage will cause a high idle, and so will a too low as the Idle speed solenoid will compensate... this is why it is preferred to get your hands on a scan tool that displays engine data to diagnos high idle problems. Paying attention to TPS voltage/percentage, and your fuel trim readings.

There is also a idle relearn proceedure which must be completed whenever you

correct a vaccum leak
disconnect battery
replace ISC
replace ECM
replace TPS

Usually if you replace the ISC, the engine will start up high as hell, but at the next start up will level out. This is the ECM compensating, but you will experience idle surging if you do not perform idle relearn.