Cruise Control Ecu

[LANLEX]

The cruise control on my 1991 LS400 does not work. The light is lit on the instrument panel when I push the main control switch. But when I push the level down to SET, it does not engage. I took it to the dealer and was told that the cruise control ECU was bad. And it will cost $1,560.00 plus $120.00 for labor. I just can't afford to spend that kind of money. So I did a search on the internet and found a used cruise control ECU for $90.00.

Now here where I would need help. The ECU is located under the left side of the dashboard below the instrument panel. How do I remove the lower panel (below the steering column/instrument panel) to access to the ECU?

Your help is greatly appreciated!

[SKperformance]

moved to LS section

[LANLEX]

moved to LS section

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Thanks SKperformance. On the good note, I got the ECU. I still don't know how to drop the lower panel.

Here is how to get the cruise control (speed control) ECU out:

Drop the bottom plastic panel out by removing five (5) screws;

Unplug the foot light from the plastic panel;

Now you can see the cruise control ECU mounted with one screw (10MM) just above the emergency brake pedal;

Remove the 10MM screw to drop the ECU;

Unplug the two big connectors from the ECU;

Now you can slide the ECU through.

Part number of the Speed Control ECU: Toyota 88240-50011 or DENSO 036040-1331 - 12V

Cheers

[LANLEX]

moved to LS section

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Thanks SKperformance. On the good note, I got the ECU. I still don't know how to drop the lower panel.

Here is how to get the cruise control (speed control) ECU out:

Drop the bottom plastic panel out by removing five (5) screws;

Unplug the foot light from the plastic panel;

Now you can see the cruise control ECU mounted with one screw (10MM) just above the emergency brake pedal;

Remove the 10MM screw to drop the ECU;

Unplug the two big connectors from the ECU;

Now you can slide the ECU through.

Part number of the Speed Control ECU: Toyota 88240-50011 or DENSO 036040-1331 - 12V

Cheers

Well! I got the new ECU and replaced the old one with it. Unfortunately it did not fix the speed control problem. When I pressed the Main Cruise control, the light comes on the dash board, but whe press down the Set level, nothing!!! The cruise control does NOT engage.

I guess the dealer's diagnostic was WRONG! And they wanted to replace it for $1,560.00 plus $120.00 for labor.

Well, I'm back to square one and still need HELP!

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[99lsguy]

I think you should check a fuse......

I'll try to find out...........

[99lsguy]

You could have a bad:

Stop Light switch circuit.......this circuit signals to cancel the cruise when you touch the brake. the cruise switch is working........but it's thinking you've got your foot on the brake so it won't engage......

the stop light switch on my 99 LS is located lower left (under dash) below the fuel & trunk openers....

The fuse is ECU-B that will clear the circuit - remember, this 99LS but should be similar....

preche.pdf

[LANLEX]

You could have a bad:

Stop Light switch circuit.......this circuit signals to cancel the cruise when you touch the brake.  the cruise switch is working........but it's thinking you've got your foot on the brake so it won't engage......

the stop light switch on my 99 LS is located lower left (under dash) below the fuel & trunk openers....

The fuse is ECU-B that will clear the circuit  -  remember, this 99LS but should be similar....

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Thanks 99lsguy. Per your suggestions, I was looking for the stop light switch and fiddling around that area, but I did not have time to check anything. Now my cruise control starts working by itself! May be it was a loose connection? or a Gremlin's enjoying his ride in my Lex. Anyway, my O/D light stops flashing and my cruise control is working now! YAY! Still don't know why!

Cheers.

[99lsguy]

Thanks 99lsguy.  Per your suggestions, I was looking for the stop light switch and fiddling around that area, but I did not have time to check anything.  Now my cruise control starts working by itself!  May be it was a loose connection?  or a Gremlin's enjoying his ride in my Lex.  Anyway, my O/D light stops flashing and my cruise control is working now!  YAY!  Still don't know why!

Cheers.

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Hey, maybe you did "fiddle" enough....could have been loose - thus causing a break in the circuit.

Glad it's fixed