How To Install Wide Open Throttle Switch

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Throttle position switch

The purpose of this test is to investigate the operation of the idle and full throttle position switches.

How to perform the test

View connection guidance notes.

1. Utilize manufacturer's data to identify the throttle switch circuit.
2. Connect PicoScope Channel A to the idle switch excursion.
3. Connect PicoScope Aqueduct B to the total load switch circuit.
4. Turn the ignition on, engine off.
5. Minimize the assistance folio. Y'all will see that PicoScope has displayed an example waveform and is preset to capture your waveform.
6. Start the scope to encounter live data.
7. Slowly fully depress then release the accelerator pedal to activate the switches.
8. With your waveforms on screen stop the telescopic.
9. Turn off the ignition.
10. Utilise the Waveform Buffer, Zoom and Measurements tools to examine your waveforms.

Example waveform

Waveform notes

These known practiced waveforms have the following characteristics:

Aqueduct A indicates the operation of the (usually airtight) idle position switch.

• At ignition on, it has a constant, unbroken, output, just above 0 V.
• The output instantly switches upwards to just below five V when the throttle moves from its idle position and remains there until the throttle position returns.
• The output instantly switches back to just higher up 0 V when the throttle returns to its idle (closed) position.

Aqueduct B indicates the operation of the (normally open) total-throttle position switch.

• At ignition on, it has a constant, unbroken, output, just below 5 5.
• The output instantly switches downwardly to just above 0 V when the throttle is at the full load (broad open) position and remains there whilst the throttle position is maintained.
• The output instantly switches back to just below 5 V when the throttle is released from the full load (wide open up) position.

There is no drop-out, racket, or hashing in either output betoken.

Waveform Library

Go to the drop-downwardly carte du jour bar at the lower left corner of the Waveform Library window and select, Throttle position switch.

Further guidance

The throttle position switch signals the movement and position of the throttle valve to the Engine Command Module (ECM). The switch unit is installed at the throttle housing and attached to the throttle butterfly spindle.

Throttle position switches can exist configured in unlike means, so it will be necessary to bank check manufacturer specifications for last and switching data. However, the general principles of operation are similar.

Within the unit of measurement in that location are two sets of contacts, with each having an open or a closed state. This allows it to signal three possible throttle position states, such every bit:

• Throttle closed – idle switch closed and full load switch open.
• Throttle part open – idle switch open and total load switch open.
• Throttle fully open – idle switch open and full load switch airtight.

The throttle position switch is ordinarily a iii-wire device with a v volts supply (12 volts on some very early on systems). A typical pin configuration might be (Hella manufactured switch):

• Pin 1 – voltage supply (5 5).
• Pivot ii – full load signal.
• Pivot three – idle switch signal.

Throttle position switch faults can exist both electrical and mechanical:

• Open up, short and high resistance faults in connectors and circuits.
• Corrosion and stress fractures in the switches.

A faulty throttle valve switch can cause:

• Malfunction Indicator Lamp (MIL) illumination.
• Diagnostic Trouble Codes (DTCs).
• Erratic or out of tolerance idle speeds.
• Stalling.
• Poor or no acceleration.
• Full load driveability issues.
• General erratic running.

Diagnostic trouble codes

Choice of component related Diagnostic Trouble Codes (DTCs):

P0068

P0120

P0121

P0122

P0123

P0124

P0220

P0221

P0222

P0223

P0224

P0225

P0226

P0227

P0228

P0229

P0510

View more

Disclaimer
This help topic is field of study to changes without notification. The information within is carefully checked and considered to exist right. This information is an instance of our investigations and findings and is not a definitive procedure. Pico Engineering science accepts no responsibility for inaccuracies. Each vehicle may exist dissimilar and require unique test settings.

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Source: https://www.picoauto.com/library/automotive-guided-tests/throttle-switch/

Posted by: smithshord1965.blogspot.com

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