after driving 15 mins or so the check engine light comes on and the automatic kicks up about 200 rpm.

 

Find out what the code is from the ecu.

 

Checker does not have the scan tool, I guess I could try autozone. or is there another way to check it for free? thanks

 

Look at your ecu it will have a flashing red light, one fast flash means "1" a long flash means "10" so find out what number it is and then tell us.

If it goes 1long flash then right after that no pause 1 fast flash that means 11.

or you can find the little blue jumper under the dash and put a paper clip in it to connect the 2 wires and the check engine light on the cluster will flash just like the above.
The car has to be in the run position.
Just when you drive it and it comes on , pull over dont turn the car off and get the code.

 

code 1. and sometimes it idles up and down like im tapping on the gas pedal. The check engine lights comes only after driving 60 mph for a couple minutes. but the ecu is always flashing. The light stays on until I shut off and restart and if I continue to drive around the city at 30-40 it never comes on.

The FA-Q says 1 is an O2 code but why would it make the tranny react?


Modified by ricerodder91EX at 9:52 PM 2/6/2008

 

It doesn't. That problem is totally unrelated.

First of all, tell us what car you drive, what engine and what year.

Second, is it bitterly cold where you are at, there is a shift light grid under the shifter on 88-91's that have a thick contact grease. In very cold weather, the spring loaded contacts may bind on the grease, and seize them up. If you also have an indicator on the dash, try wiggling the gearshift in each position and see if the light flickers.

There are two problems with this system.
1: If the above problem is the case, the P indicator may not light, which will prevent you from moving the car into any other gear until the manual release is pressed with the key. If the contact is intermittent at idle, this will cause the idle to flux, I know this personally because this happened to my car a few weeks back. (No O2 code though)

2: The flicker will cause the torque converter clutch to disengage which is consistent with the 200rpm increase in engine rpm. This may happen because the D4 contacts momentarily lose contact on the shift grid, and forces the TCC off because it is electronically controlled.

3: If the torque converter was not engaging properly, it may or may not throw a code because the TCC valve can be in working order, but may be leaking or the clutch surface worn. This is not likely, but can be the case if the transmission has over 200,000 miles or so, or a rough driver.

If it continues to happen, do not drive the car if you don't have to. Not only will you lose fuel mileage, you may overheat the transmission and ruin it.

The shift grid is the white box attached to the right side of the shifter once the console cover is removed. Remove the two 10mm bolts that secure it, unplug it and pry the two halves apart. Be careful, there are spring loaded parts under low tension, and a ball bearing in there. Clean all the old grease off, and reapply some dielectric grease to the contacts. Buffing the contacts will be required if they do not shine back at you. Very common problem that is most apparent in cold weather. (20 degrees and colder)

 

91 EX All stock D16A6 is the engine code IIRC. The TCC disengage is %100 consistent with the CEL turning on. There is no flicker in D4 when the disengage happens. While the CEL is on the tranny does not behave sporatically it just runs at a higher rpm.

This is what happens every time since summer: I drive around town, the car warms up, I get on the highway and cruise at 60 mph at 2700 rpm, after a few minutes the CEL comes on and the tranny shifts or disengages the TCC or whatever is the case and the engine is now running at 2900 rpm at 60 mph.

Don't worry I've only driven it 150 miles since owning it.