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Discussion Starter · #1 ·
Good afternoon. I am new to this forum, but have posted in a similar RAV4 forum previously, and found it tremendously helpful. I have a 1997 Celica GT hatchback 5 speed manual that I recently purchased. I really enjoy the car. I have fixed several things on it, and am trying to get the cruise control working. Here is where I am at thus far: When I push the on button, it lights up and blinks. When I drive and try to engage it, it just continues to blink steadily. I purchased a shop manual, and have been working my way through it, but would welcome any assistance I can get. I checked the 4 fuses involved with the cruise control function, and they are all good. I pulled out the glovebox to get at the Cruise Control Electronic Control Unit. I found some corroded wiring/insulation and needed to do some repair. I have fixed the wires and have now checked the voltages between the pins as recommended in the service manual. I will list them as follows:

Pin 2 - 13 = 10.3 volts with clutch depressed to 0 volts with clutch out

7 - 13 = 10 with the main switch on, 0 volts with the main switch off

8 - 13 = 12.5 volts with the ignition on

10 - 13 = 0 volts parked

I didn’t have a helper to drive, so I haven’t checked 13 to 11 or 12

13 – Ground = continuity

14- 13 = 13 volts with ignition switch on

15 - 13 = 13 volts always

16 - 13 = 13 volts with brake depressed to 0 volts with brake pedal released

18 - 13 = 11.9 volts switch in the neutral position, 5.8 volts with cancel switch held, 3.8 volts with set/coast switch held on, 1.7 volts with resume/accel switch held on

19 - 13 = 0 with main switch on hold, 12 volts with main switch off

20 - 13 = 6.25 volts parked (which is higher than the manual indicates it should be (4.7-5.2),

3.08 - 3.18 volts while moving, max 3.18 volts at 70 miles/hr.

21 - 13 = 0 and 0 volts with throttle pedal pushed and released

23 - 13 = 11.5 volts (this also looks suspect)

The part that looks the oddest to me is the speed sensor, where the manual says that it should be between 3-7 volts with driving, but it barely fluctuates. I think the next step is to change the speed sensor, but I wonder if this makes sense.

I also don’t understand the throttle valve readings, VR1-Ground

I didn’t check voltage between pins 24 - 25 as it recommends yet.

As a last step, I also used paperclips and a jumper wire to connect Tc and E1 on the diagnostic plug under the hood, and the cruise control light flashed a single flash, followed about three seconds later by three consecutive flashes, then a pause and it continues to repeat this pattern of 1 and 3.

This may all be a bit confusing, but if any of you have worked on this particular problem before, I would appreciate some direction as to what else I should test and how. The manual is very helpful, but it assumes a certain level of familiarity with the testing procedures, so I am kind of guessing.

· Registered
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Discussion Starter · #2 ·
Well, maybe my previous cruise control question was too technical as a place to jump into the forum. So let me ask smaller questions. Does anyone know if the speed sensor on my Celica is what provides input to the speedometer? If the speed sensor supplies both the speedometer and the cruise control computer, then I know the speed sensor is providing an accurate signal, but if there is a separate one for the speedometer and the cruise control, then I will change the one supplying the cruise control module and see what happens.
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