well my cruise control quick working, im pretty pissed about it sence i drive 60 miles one way to work all highway. i have an 04 f150 5.4 fx4. its one of the early 04's so i have all the bugs people dont want to have. up until now, none of them have been bad. but this one i dont like at all. the only info i can find is in tsb 05-6-10. it said my shift interlock could be bad.well i already had the problem with the shifter getting stuck in park and i just wedged a hex pit on the interlock to keep the button down and havent had any problems out if it. its been this way for about 10 months. the cruise control has always worked in this condition. why now would it stop working if the interlock has been bad for some time. please help, the manual doesnt show any fuses or relays for the cruise.

 

If you would like to PM me with your e-mail address, I can e-mail you the troubleshooting info. It's a bit to long to post here. I would have to make 4 or 5 posts to get it all in the thread....

But here's some of it...

Principles of Operation

The speed control system is controlled by the powertrain control module (PCM). The speed control system is designed to maintain a selected vehicle speed between 48 and 200 km/h (30 and 124 mph). The speed control system is controlled by the steering wheel mounted switches (ON, OFF, SET/ACCEL, COAST, and RESUME), the stoplamp switch, clutch pedal position (CPP) switch, and the speed control deactivator switch. The steering wheel mounted switches are hardwired to the PCM through the clockspring.
The speed control functions include:
· turning the speed control system on. /><O></O>
· setting and maintaining the desired vehicle speed. <O></O>
· accelerating the vehicle speed. <O></O>
· decelerating the vehicle speed. <O></O>
· resuming the prior vehicle speed. <O></O>
· turning the vehicle speed control system off. <O></O>

Pressing and releasing the ON switch turns the speed control system on. Pressing and releasing the SET/ACCEL or COAST switch while the vehicle is traveling at the desired speed activates the speed control system.

Tapping the SET/ACCEL or the COAST switch while in the set mode respectively, increases or decreases the maintained vehicle speed by 1.6 km/h (1 mph) per tap. If the respective button is pressed and held, the vehicle speed continues to accelerate or decelerate until the button is released.

Pressing and releasing the OFF switch, or turning the ignition switch to the OFF position, turns the speed control system off. Applying the brake pedal puts the speed control system into the STANDBY mode. Pressing the RESUME button, when the speed control system is in the STANDBY mode causes the vehicle to accelerate to the last set speed. Resume does not function if the OFF button is pressed, the ignition switch is in the OFF position, or if the current vehicle speed is below the minimum operational speed.

The CPP switch is used on vehicles equipped with a manual transmission. When the clutch pedal is applied with the vehicle speed control system engaged, the normally closed switch opens and signals the PCM to deactivate the speed control.
Whenever the speed control system is engaged and active, a speed control icon on the instrument cluster or message center is illuminated.

The speed control deactivator switch is provided as an additional safety feature. Normally, when the brake pedal is applied, an electrical signal from the stoplamp circuit to the PCM deactivates the system. Under increased brake pedal effort, the speed control deactivator switch opens and removes the voltage from the PCM input circuit, releasing the throttle.
The inputs to the PCM are:
· Output shaft speed (OSS) sensor <O></O>
· Digital transmission range (TR) sensor <O></O>
· Speed control switch(es) <O></O>
· CPP switch <O></O>
· Speed control deactivator switch <O></O>
· Stoplamp switch <O></O>
· Accelerator pedal position sensor <O></O>
The outputs of the PCM for the speed control system are:
· Speed control indicator lamp <O></O>
· Throttle command <O></O>

The speed control system throttle position is completely controlled by the PCM through the electronic-controlled throttle body. Speed control electronics are contained entirely within the electronic throttle control (ETC) subsystem.

When the speed control system is active, the PCM corrects for deviations in the actual vehicle by proportionally moving the throttle plate. The PCM modulates the throttle to minimize error between the actual vehicle speed and the desired speed.

The PCM strategy uses the throttle control for smooth accelerations.

The PCM sends a serial message over the controlled area network (CAN) to the instrument cluster to control the operation of the speed control telltale.

In the event of an OFF command or a deactivation request from the speed control deactivator switch, the speed control system carries out a hard deactivation and immediately returns the throttle to the idle position.

The speed control system provides self-diagnostics. The speed control is disabled anytime an error is detected in the system. No cluster telltale or message center messages are displayed when faults occur. Fault codes are logged by the PCM.

An ETC system fault also causes the speed control system to be disabled. In this case, an ETC system warning telltale (wrench light) or a message center message is displayed.

Additionally, the following conditions cause the speed control system to deactivate:
· Transmission gear selector in a position other than D or OD <O></O>
· Clutch pedal is pressed <O></O>
· Speed control set speed is over-ridden with the accelerator pedal for a period longer than 5 minutes <O></O>
· Parking brake is applied <O></O>
· Vehicle speed loss from set speed of greater than 16 km/h (10 mph) occurs <O></O>
· Vehicle speed falls below the minimum allowable limit of 48 km/h (30 mph) <O></O>
· Speed control switch pressed or stuck longer than 2 minutes <O></O>
<O></O>
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