• Topic ID: id_12373355
  • Version: 1.2
  • Date: Jul 5, 2019 10:03:32 PM

Shim Circuit Continuity

Disclaimer

Depending on your service agreement, not all service tools, diagnostics, and utilities referenced in this document may be accessible. Contact your sales person for information on available service license packages.

Diagnostic Description

Diagnostic Path

Diagnostics > Hardware Location > Pen Panel Cabinet > Shim Supply Diagnostics

Diagnostics > System Function > Magnet > Shim Supply Diagnostics

Purpose

This diagnostic ensures each channel can be set to the preset current (100 mA) and that the channel has the desired current; has the proper polarity; and is isolated (meaning there is no crosstalk) between other channels.

This diagnostic is part of the Shim Supply Diagnostics, that comprise a series of tests that verify and display various shim supply values by communicating from the SCP to the shim supply via the CAN link.

Components Tested

  • Shim supply

  • Coil channels

  • RTD channels

Requirements

Software configuration:

  • Standard software

  • CAN communications NOT emulated

Hardware configuration:

  • CAM Chassis: SCP and AGP processor boards and bridge board

  • Shim supply, cabling, etc.

Block Diagram

Figure 1. Shim Supply Block Diagram

Test Sequence

  1. Set the Test Duration to the number of seconds desired.

  2. Select Shim Circuit Continuity Check, then press Run.

  3. The diagnostic conducts the following tests in sequential order:

    • Issues a command that turns the shim supply’s fault monitoring off.

    • Loops through each channel, setting a single channel to 100 mA and all others to 0.0 mA. For each iteration (corresponding to setting a channel to 100 mA), the diagnostic issues a command that sets the current for each of the shim supply’s channels.

    • Issues a command that instructs the shim supply to return the present current for each coil channel.

    • Issues a command that sets the current on each channel to zero.

      note:

      The shim supply is first checked to ensure it is in the proper state. Commands to the shim supply are issued via the CAN interface on the SCP.

  4. The diagnostic displays the results

Expected Results

Example test output is shown in the illustration below. On the actual display, input, shim supply state, and test condition errors are shown in red.

The table displays the channels’ current measurements and a text description of good and bad channels. In this sample, channel 2 failed to read back ~100 mA.

Figure 2. Sample Test Output

Finalization

Before scanning, perform a TPS reset.