Mechanics

CRUISE CONTROL NOT FUNCTIONING

1998 Honda Accord

Engine Mechanical problem
1998 Honda Accord 4 cyl Two Wheel Drive Automatic 160K miles

This car has a cruise control master on/off switch on the dashboard to the left of the steering wheel and a separate set of controls (RESUME/accel, CANCEL, SET/decel) mounted on the right hand side of the steering wheel. When the cruise control master on/off button is pressed, the light on the button turns on. When the car is being driven above 30 MPH, pressing the SET button does nothing. It should cause the speed to be set and cause an indicator on the dashboard instrument panel to be lit.
I have a Haynes manual for this car, and have tried to isolate the problem with the cruise control. I have located and checked the fuse. The original fuse is good and it is clean. The brake switch appears to work based on the fact that the brake lights work. The control cable between the servo/amplifier and the throttle appears to be adjusted properly. The vehicle speed sensor on the countershaft measures 475 ohms, and the Haynes manual indicates that it should be between 400 and 600 ohms, so that appears to be good. I was unable to access the vehicle speed sensor on the mainshaft as it is located underneath the battery, and disconnecting the battery will lead to other problems (radio anti-theft device). I could pursue that, but the fact that the speedometer works suggest that this sensor is also working. The Haynes manual did not have any other suggestions.
A Honda dealer wanted $100 just to connect their computer to the onboard diagnostics. I declined that for now, but did buy an Actron CP9180 AutoScanner. I am still learning that tool (and OBDII), but did get it to tell me that all the diagnostics passed, and there were no codes to be checked out.

Are there any known failure modes or diagnostics that can be tried? Any suggestions on how to get the cruise control to work will be appreciated!


http://www.2carpros.com/forum/automotive_pictures/535400_1998HondaAccordLXcruisemasteronoffdash_1.jpg



http://www.2carpros.com/forum/automotive_pictures/535400_1998HondaAccordLXcruisemasteronoffdashlit2_1.jpg



http://www.2carpros.com/forum/automotive_pictures/535400_1998HondaAccordLXcruisecontrolsteeringwheel2_2.jpg

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Gordon2
June 5, 2010.




Hi gordon2,

The brake switch works on 2 different circuits, one for the brake lights and the other circuit is for the cruise control.

The brake lights might work but the cruise control circuit could be faulty or the brake switch out of adjustment.

Have you gone through all the diagnostic steps?
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KHLow2008
Jun 6, 2010.


http://www.2carpros.com/forum/automotive_pictures/535400_1998HondaAccordLXbrakeswitchcropped_1.jpg



Hi KHLow2008,
Thank you for your quick and helpful reply regarding the cruise control problem on my 1998 Honda Accord 4 cyl Two Wheel Drive Automatic 160K miles.

In regards to “The brake switch works on 2 different circuits, one for the brake lights and the other circuit is for the cruise control,” how would I test the two different circuits? The Haynes manual indicates, “The break pedal position (BPP) switch (or stop lamp switch) deactivates the cruise control system. Have an assistant press the brake pedal while you check the stop lamp operation.” If there is more testing that can be done, it may not be covered in the Haynes manual. I will take a closer look at the switch. [Mirror image photo now posted above.] I recall seeing a button (near the mechanical mechanism below the dash) that moves when the brake pedal moves, but did not pay attention to the number of wires connected to the switch.

In regards to, “Have you gone through all the diagnostic steps?” I have followed what is listed in the Haynes manual, with the exception of checking out the “vehicle speed sensor on the mainshaft” as I indicated above. A side thought on that, the tachometer works, and I might be able to try running the engine with and without that connected to demonstrate the sensor works.

While admitting that I am not an auto-mechanic, I am suspicious of the set of controls (RESUME/accel, CANCEL, SET/decel) mounted on the right hand side of the steering wheel. That is directly tied to the function that does not work, and there was no testing of that in the Haynes manual. What are they connected to? Could a wire have come loose when some other work was previously done on this car?

Tiny
Gordon2
Jun 6, 2010.
The Haynes manual is not correct about the brake lights and cruise control circuit for Honda vehicles.

There should be 4 wires for the brake switch, 2 for each circuit.

The brake switch for the brakelights would contact when the brake pedal is depressed to turn the brake lights on while the cruise control circuit is constantly on till the brake pedal is depressed to break the circuit to discontinue the cruise control. If there is too much clearance between the brake pedal and switch, the cruise control would not work.

An easy test would be to insert a thin cardboard between the brake pedal and switch to reduce any clearance and test if the cruise control works.

I will send you the files for testing the Set/Resume/Cancel and brake switch.

KHLow2008
Jun 7, 2010.


http://www.2carpros.com/forum/automotive_pictures/535400_98Accordbrakeswitchterminals_1.jpg



http://www.2carpros.com/forum/automotive_pictures/535400_98Accordbrakeswitchcontinuity_1.jpg



KHLow2008,

To test the break switch, I disconnected the 4P connector and used an ohm meter to test continuity. With the brake pedal released, there is no continuity at all. With the brake pedal pressed, there is continuity between terminal 2 and 3. When I put a small flat shim between the released brake pedal and the switch, I do get continuity between 1 and 4. I believe the problem is as you described, “If there is too much clearance between the brake pedal and switch, the cruise control would not work.”

It turns out that if I had looked in the Haynes manual section focused on the brake switch (rather than cruise control), I would have found some useful information regarding testing, but the adjustment information provided leaves me wondering if there is a smarter, easier way. That was the case with your suggestion regarding an easy test.

Any suggestions on how to adjust this properly will be appreciated. It looks like I should be able to loosen one nut on the brake switch, move the switch toward the brake pedal, test/adjust and tighten the nut. Is it that easy? It seems worth asking because brakes and brake lights are things that I want to work for safety reasons. [Edit: See image below. The adjustment seems to be straight forward.]


http://www.2carpros.com/forum/automotive_pictures/535400_98Accordbrakeswitchadjustment_2.jpg



Thanks so much for your help.
Gordon

[Update: Adjusted the clearance on the brake switch and cruise control now works!!! One odd thing, the (1, 4) and (2, 3) pairings on the diagram above were opposite of what I measured - or I misread the numbering.]

Tiny
Gordon2
Jun 12, 2010.
Sorry for getting back to you late. Was away for a few days.

Glad to know you have fixed the problem.

Have a great day.

KHLow2008
Jun 17, 2010.
Hi KHLow2008,

I have exact issue with my 1998 Honda accord EX. It looks like you have send some files to Gordon2, could you please share with me.

"I will send you the files for testing the Set/Resume/Cancel and brake switch."

Tiny
AbhayP28
Apr 8, 2013.
BRAKE PEDAL POSITION SWITCH TEST

1. Disconnect the 4P connector from the switch (A).

2. Remove the brake pedal position switch.

3. Check for continuity between the terminals according to the table.

4. If necessary, replace the switch or adjust the pedal height.

Gordon2's 12 June reply described the brake switch test. Refer to the diagram in that post.

KHLow2008
Apr 12, 2013.

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