Automative diagnostic testing apparatus

• US 5,461,908 A
• Filed: 07/01/1994
• Issued: 10/31/1995
• Est. Priority Date: 03/27/1992
• Status: Expired due to Fees

• Current Assignee: Abes Electronics Center Incorporated
• Original Assignee: Abes Electronics Center Incorporated
• Inventors: Armstrong, Richard W.
• Primary Examiner(s): RAEVIS, ROBERT R
• Application Number:
  US08/269,828
• Time in Patent Office: 487 Days
• Field of Search: 73/118.1, 324/772, 324/503, 324/555, 340/648
• US Class Current: 73/114.61
• CPC Class Codes: F02P 17/02 Checking or adjusting ignition timing
• CPC Class Codes: G01R 31/006 on road vehicles, e.g. automobiles or trucks testing of ignition installations peculiar to internal combustion engines F02P17/00

Abstract

A diagnostic testing apparatus for testing an automotive IAC motor normally controlled by pulse signals from the electronic control module (ECM) of an automotive electrical system, which apparatus is coupled between the ECM and the IAC motor circuits and provides first circuits re-establishing a normal signalling communication therebetween, and second circuits comprising parallel test circuits including indicators and switches constructed and arranged for indicating faults in the component.

Claims

1. A diagnostic testing apparatus for testing the operation of an automotive idle air control (IAC) motor having a pair of operating circuits with positive and negative input signal ports and plural stepper positions for regulating engine idle speed, said operating circuits normally being directly connected to an electronic control module (ECM) of the automotive electrical system and being power controlled only by the ECM, comprising:

first means including coupling means for removably coupling said testing apparatus between the ECM and the operating circuits of IAC motor to be tested, and further including first circuit means constructed and arranged for re-establishing normal series power control connection of the ECM with each of the IAC motor operating circuits; and

second means comprising a plurality of testing circuits, each of which connects across one of the power control connections of the first circuit means in parallel with the associated operating circuit of the IAC motor, each testing circuit being responsive to the ECM power control to the associated operating circuit and including at least one indicator device for indicating an operating condition of the associated operating circuit.

2. The system of claim 1 wherein each indicator device comprises a light emitting diode.

3. The testing apparatus of claim 1 wherein the indicator devices of the testing circuits comprise bipolar pairs of light emitting diodes for indicating faults occurring in the IAC motor, each diode corresponding to one of the signal ports, and wherein the ECM pulse train signals to the signal ports normally energize the respective diodes associated therewith.

4. The testing apparatus of claim 3 wherein the testing circuits further comprise a current limiting resistor connected in series with each bipolar pair of diodes to restrict pulse current flow to a predetermined minimum value.

5. The apparatus according to claim 1, which includes switch means constructed and arranged for selectively disabling at least one of the testing circuits.

6. The testing apparatus of claim 1 wherein the operating circuits comprise a pair of IAC coil windings having at least two bypass air control positions responsive to different pulse train signals generated through the first circuit means by the ECM, and wherein the second means includes a testing circuit associated with each power control connection of the first circuit means including different indicator means for indicating the integrity of the air control positions.

7. The testing apparatus of claim 6 including means for accommodating adjustment of the engine idle speed to a desired level for testing, and comprising at least one switch for each testing circuit and its associated first circuit means.

8. A diagnostic testing apparatus for testing the circuit integrity of an idle air control (IAC) motor having a pair of operating circuits with positive and negative signal ports and at least two bypass air control positions and being controlled in its normal operation in response to different pulse train signals generated at the signal ports by an electronic control module (ECM) of the automotive electrical system, said testing apparatus comprising:

coupling means for removably coupling said testing apparatus between the ECM and the operating circuits of the IAC motor to be tested and including first circuit means for re-establishing normal series pulse train circuit connections of the ECM to the signal ports of said IAC motor operating circuits, and

second means constructed and arranged to provide a testing circuit associated with the series circuit connections of the ECM to each signal port of the operating circuits, each testing circuit being connected across the first circuit means in parallel with an operating circuit of the IAC motor and being responsive to the pulse train signals of the ECM to such associated operating circuit, and each testing circuit including an indicator device for indicating an operating condition in the IAC motor.

9. A diagnostic testing apparatus for testing the operation of the idle air control (IAC) system in an automotive engine where the idle speed is set by a two-coil stepper motor having two IAC coil circuits, the normal operation of which is activated in response to power pulse signals generated by an electronic control module (ECM) of the automotive electrical system, the IAC system being normally directly connected to and power controlled by the ECM, said testing apparatus comprising:

coupling means for removably coupling said testing apparatus between the ECM and the IAC coil circuits to be tested and including first circuit means constructed and arranged for re-establishing normal series power control connections of the ECM to each IAC coil circuit;

second means constructed and arranged to provide a plurality of testing circuits, each of which connects across the first circuit means in parallel with at least one associated IAC coil circuit, each testing circuit being responsive to the ECM power control to the associated IAC coil circuit and including at least one indicator device for indicating an operating condition of such IAC coil circuit; and

switch means constructed and arranged for selectively disabling or connecting the ECM power pulse signals from the individual IAC coil circuits, each switch means controlling the series power control connection to one of the IAC coil circuits and the associated testing circuit.

10. A diagnostic testing apparatus for testing the circuit integrity of an idle air control (IAC) system in an automotive engine wherein the idle speed is set by a two-coil stepper motor having two IAC stepper coil circuits associated plural signal ports, the normal operation of the IAC stepper coil circuits being activated in response to power pulse signals generated by an electronic control module (ECM) of the automotive electrical system and the IAC stepper coil circuits being normally directly connected to and power controlled only by the ECM, said testing apparatus comprising:

coupling means for removably coupling said testing apparatus between the ECM and the IAC stepper coil circuits to be tested and including first circuit means for re-establishing a normal series power control connection of the ECM to the associated signal ports of each IAC stepper coil circuit; and

second means constructed and arranged to provide a plurality of testing circuits, each of which connects across one power control connection of the first circuit means in parallel with an associated IAC stepper coil circuit, each testing circuit being responsive to the power control of the ECM to the associated IAC stepper coil circuit and including at least one light emitting diode with an associated current limiting resistor for indicating the integrity of the IAC stepper coil circuit; and

switch means constructed and arranged for selectively disabling or connecting the ECM power pulse signals from the individual IAC stepper coil circuits, each switch means controlling the series power control connection to one of the IAC stepper coil circuits and the associated testing circuit.