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If you are replacing a digital amplifier, you should swap the reference resistor over to the new amplifier. One frequently-heard complaint is a ticking or clicking sound coming from the actuator, along with the complaint that cruise control is inoperative. This is a symptom of a problem with the feedback potentiometer, where the amplifier believes (inaccurately) the throttle position is too high, causing the amplifier to run the actuator motor in an attempt to bring the throttle linkage to idle position. The clicking is the ratchet in the actuator clutch, since the actuator motor is also disengaged in this situation.
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But as we mentioned, there are other components related to this system which may need to be checked as well. Using your ohmmeter, you can verify that all the switches are switching when they are supposed to, and by actuating them several times (including with more and less force) you can check for intermittent contacts. Because the switch’s connector contacts (down in the steering column) can also contribute to the problem, you might consider also measuring the switch values directly at the amplifier plug.
Installing cruise control on my 10-year-old Suzuki Grand Vitara - Team-BHP
Installing cruise control on my 10-year-old Suzuki Grand Vitara.
Posted: Sat, 16 Jul 2022 07:00:00 GMT [source]
Identity Verification for Mercedes-Benz XENTRY Diagnosis, Programming and Theft Relevant Parts
We have looked at each of the four major components and a few related systems and learned how they function and how they can be tested. We also became aware of a few Service Information bulletins with useful information for this convenience system. And finally we learned about a few of the more common complaints, learned their likely causes and how to correct them. The driver must manually bring the vehicle up to speed and use a button to set the cruise control to the current speed. A governor was used by James Watt and Matthew Boulton in 1788 to control steam engines, but the use of governors dates at least back to the 17th century.
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Pins 9 and 13 are the throttle-position sensor power source and returned position voltage, respectively. The position sensor, which is a high-reliability potentiometer, is grounded at W1 along with the amplifier. Both the brake light switch and the cruise control system get power from Fuse 9, so a fuse failure ensures the system cannot operate.
References
This symptom is often caused by a poor ground to the actuator at Pin 1 of the actuator connector, located in the engine compartment. Originally, the E-Tempomat control amplifier was a purely analog circuit, with a different part number for each vehicle. Since vehicles have different power-to-weight ratios, a different reaction by the amplifier is needed – for example, a 190D 2.2 needs to approach the throttle more aggressively when the speed drops, while the same reaction in a 560SL might be a little scary. Later versions, including the replacements available today, were digitally controlled, and a coding plug was attached to the amplifier to set the specific throttle response and other parameters.
Other ways to switch the system off include tapping the brakes, pressing the clutch pedal (in manual-transmission vehicles), or if the system detects an unreasonable deceleration (about 1.5 m/s2). In 1965, American Motors Corporation (AMC) introduced a low-priced automatic speed control for its large-sized cars with automatic transmissions.[10] The AMC "cruise command" unit was actuated through a push-button on the dashboard once the car's desired speed was reached. The throttle position was automatically adjusted by a vacuum control that opened and closed the throttle based on input from the speedometer cable rather than through an adjustable control on the dashboard.[10][11] The unit would shut off anytime the brakes were applied. The cruise control systems of some vehicles incorporate a "speed limiter" function, which will not allow the vehicle to accelerate beyond a preset maximum; this can usually be overridden by fully depressing the accelerator pedal. Most systems will prevent the vehicle from increasing engine speed to accelerate beyond the chosen speed.
On an engine, the governor uses centrifugal force to adjust the throttle position to adapt the engine's speed to different loads (e.g., when going up a hill). There was a time when superchargers and turbochargers were pretty much limited to race cars and certain high performance applications. Now, with the newer technology and the global drive for fuel efficiency and more power, turbochargers seem to be found on almost... Classic owners are passionate about their cars, and many can’t live without their cruise control.
Classic Mercedes-Benz Cruise Control – E-Tempomat System
Cruise control (also known as speed control, cruise command, autocruise, or tempomat) is a system that automatically controls the speed of an automobile. The system is a servomechanism that takes over the car's throttle to maintain a steady speed set by the driver. Another complaint we’ve heard is that the cruise control system operates more-or less fine, but tends to ‘hunt’, or constantly change throttle position from a little too much to a little too little, almost continuously while in operation. Found especially in higher-mileage vehicles, this is a clear symptom of a worn feedback potentiometer in the actuator. What happens is that the potentiometer resistance surface eventually wears out in just one small spot, and the only solution is a new actuator. That covers all 14 pins of the amplifier, and diagnosis is as simple as taking 14 readings (and 2 of them are grounds!).
An mentioned, vehicle speed is a series of pulses, with increasing frequency indicating increasing speed. In Mercedes-Benz vehicles with a mechanical speedometer cable, there is a sensor on the back of the speedometer that generates these pulses, while in electronic speedometer models the speedo re-forms the pulses received from the inductive sensor at the transmission output shaft. Since several other systems use the vehicle speed signal – CIS-E engine control, fuel pump relay, air conditioning and radio to name a few – there will be other systems affected if the vehicle speed signal is faulty. The cruise control takes its speed signal from a rotating driveshaft, speedometer cable, wheel speed sensor from the engine's RPM, or internal speed pulses produced electronically by the vehicle.
On the latest vehicles fitted with electronic throttle control, cruise control can be integrated into the vehicle's engine management system. Modern "adaptive" systems include the ability to automatically reduce speed when the distance to a car in front, or the speed limit, decreases. With the Tempomat (cruise control, (Distronic without radar)) plus automatic transmission, you can do your right foot a big favor.On longer journeys at constant speed it can hand over to the Tempomat. By means of a lever on the steering wheel you can select any desired speed above 30 km/h//19 mph and the Tempomat will maintain it. If the driver overrides the set speed by pressing the accelerator, for example when passing, upon releasing the pedal the vehicle will coast down and resume the set speed. It is important to avoid shifting into neutral in an automatic transmission vehicle, as this will cause the engine to rev up to the over-rev limiter setting.
Cruise control is less flexible on vehicles with a manual transmission because depressing the clutch pedal and shifting gears usually disengages the cruise control. The "resume" feature has to be used each time after selecting the new gear and releasing the clutch. Therefore, cruise control is most beneficial at motorway/highway speeds when top gear is used virtually all the time. Also note that other systems, notably ABS and the Anti-Theft Alarm, also connect to the brake light circuit, but rarely cause problems with cruise control. The cruise control amplifier, as an electronic control unit, cannot be tested directly, but we can easily say that if all of the inputs and outputs to the unit are correct, either the system is operating correctly or the amplifier needs to be replaced. The unit only has 14 pins, so it is fairly quick and easy to check every one of them and come to a conclusion.
Study shows drivers don't understand how radar cruise control works - Drive
Study shows drivers don't understand how radar cruise control works.
Posted: Mon, 11 Apr 2022 07:00:00 GMT [source]
Not sure if this helps, but for BMW Z3s they made a kit that allowed for you to just basically plug it in. I recommend going to dealership, get estimate, and then see if it has a part number you can cross reference for the kit to see if there are cheaper options online, or just buy the dealers kit. Stack Exchange network consists of 183 Q&A communities including Stack Overflow, the largest, most trusted online community for developers to learn, share their knowledge, and build their careers. 4MATIC is available on virtually every Mercedes-Benz vehicle so you should know the ins and outs, including service and maintenance recommendations. At the heart of the matter, the 4MATIC® system applies power to the front axles through a transfer case in the...
Another inventor named Harold Exline, working independently of Riley, also invented a type of cruise control that he first installed on his car and friends' cars. Again, while these older models probably don’t make up the bulk of your customer base, we all know just how enthusiastic and passionate these classic-model owners can be. Your efforts at keeping their “baby” operating as designed will be appreciated by your customers, and likely profitable for you.
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