Project Start Prompt

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The mechanical placement repair is still running; it is rebuilding the 220-part board against actual footprint geometry rather than accepting the earlier invalid placement. The completion gate remains zero overlaps, zero out-of-bounds parts, and verified CMC/USB access.
Received notification from "PCB Placement Repair" that it finished — picking the work back up.

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The project files were updated successfully:
  • Saved the ECU PCB Layout Checklist, including the four proposed 3.2 mm M3 holes and 8 mm keepouts.
  • Updated the architecture and connector notes for the external GM-style 40–304 kPa MAP sensor.
  • Recorded MAP wiring as A = SENSOR_GND, B = MAP_IN, C = SENSOR_5V.
  • Removed onboard MAP sensor, hose-barb, and pressure-port requirements from the documentation.
The placement executor completed, but I could not retrieve and independently reconcile its final report before tool access ended. The last verified pre-repair state had many components outside the 180 × 120 mm outline and 375 unrouted connections, so the repaired placement is not yet approved for routing.
Remaining work:
  • Verify the MAP reservation graphics were actually removed.
  • Confirm all four mounting holes exist at the specified coordinates.
  • Check overlaps, board bounds, mounting-hole keepouts, CMC access, Teensy USB access, and analog isolation.
  • Resolve schematic/ERC issues before routing.
  • Route and run final DRC, thermal, transient, and manufacturability reviews.
Execution stopped because your ACUs ran out.
Verify repaired placement
Check mounting holes
Review schematic issues
Validate MAP cleanup
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Files

Schematic

Layout

Preview

ECU PCB Layout Checklist
Mechanical baseline
  • Board: 180 × 120 mm, 4 copper layers, 3 mm corner radius.
  • Remove the obsolete onboard MAP sensor, vacuum port, and MAP edge reservation.
  • External MAP sensor uses the main 80-way Molex CMC harness.
  • Add four non-plated 3.2 mm finished M3 mounting holes at board coordinates relative to the lower-left corner:
    • MH1: (7, 7) mm
    • MH2: (173, 7) mm
    • MH3: (7, 113) mm
    • MH4: (173, 113) mm
  • Maintain an 8 mm diameter keepout around every mounting hole, free of components, copper, traces, vias, and silkscreen text.
External MAP interface
  • Sensor: external GM-style 40–304 kPa absolute MAP sensor, suitable for typical applications up to approximately 25 psi boost.
  • Pin A: SENSOR_GND.
  • Pin B: MAP_SIGNAL.
  • Pin C: +5V_SENSOR.
  • Sensor supply: nominal 5.1 V ratiometric interface.
  • Input circuit must safely scale and clamp the published possible 5.044 V maximum output below the Teensy 4.1 3.3 V ADC limit.
  • Firmware must use the sensor’s published transfer curve rather than a generic 3-bar calibration.
Placement priorities
  • Keep the Molex CMC connector accessible at an enclosure-facing edge.
  • Keep the Teensy USB connector accessible at the opposite enclosure-facing edge.
  • Preserve vertical and lateral clearance to remove and replace the socketed Teensy.
  • Group battery protection, regulators, injector drivers, relay drivers, and high-current returns in the noisy power/output zone.
  • Group knock, ADC/reference, MAP/TPS/temperature inputs, and crank/cam conditioning in the quiet analog zone.
  • Place connector protection components directly behind the corresponding connector pins.
  • Place every decoupling capacitor immediately beside its IC supply pin.
  • Completion gate: zero body overlaps, zero out-of-bounds components, zero keepout violations, and verified connector/USB service access.
Stackup and routing order
  • L1: components and critical/local signals.
  • L2: continuous ground plane.
  • L3: power distribution and secondary signals.
  • L4: remaining signals.
  • Route in order: battery/protection/regulators; grounds and power; injectors and relays; knock; crank/cam; analog sensors; CAN; coil/tach/speed outputs; SPI and remaining digital nets.
  • Keep high-current return paths out of the sensor-ground area and do not split the ground plane beneath critical signals.
Final validation
  • Run schematic ERC before routing release.
  • Remove dangling traces before autorouting.
  • Verify all footprints, connector cavity mapping, and Teensy pin allocation.
  • Run placement DRC before routing.
  • Finish with zero unintentional airwires and zero blocking DRC errors.
  • Review voltage/current ratings, thermal paths, automotive transient protection, enclosure clearances, and manufacturability before export.

  • Mechanical baseline

  • External MAP interface

  • Placement priorities

  • Stackup and routing order

  • Final validation