Project Start Prompt

Thought for 12 sec

flux

I’m reconciling the completed schematic/ERC work against the live project now. If the schematic gate is genuinely clear, I’ll continue through placement cleanup and pre-routing checks without pausing.

Thought for 10 mins 38 sec

Thought for 11 sec

Checking FKNRUN Schematic ERC progress…

Thought for 11 sec

Reading FKNRUN Schematic ERC's report…

Thought for 14 sec — Revising configuration plan

Checking Placement and Mechanical Cleanup progress…

Thought for 11 sec — Considering execution processes

Awaiting 1 background task

"PCB Placement Repair" completed.

Thought for 7 sec

flux

The schematic executor reduced ERC from 218 floating pins and 8 single-pin nets to 2 floating pins and 1 single-pin net. It completed most supply, ground, ADC, connector, CAN, protection, and unused-pin wiring.

Two electrical decisions remain before routing:

Select the MAX9926 crank/cam threshold mode for U10.
Remap VSS_GPIO; the current Teensy symbol exposes GPIO0–41, so the planned GPIO42 assignment is unavailable.

The placement-repair executor also completed, but I could not retrieve and reconcile its final report. Therefore the four overlap/access repairs, mounting-hole keepouts, CMC clearance, and Teensy service access are not yet independently accepted.

Routing has not started. Next session should reconcile placement, resolve the two schematic items, rerun ERC/DRC, remove stale traces, and then begin routing. Execution stopped because your ACUs ran out.

Waiting for input

Files

Schematic

Layout

3D View

ECU Connector and Teensy 4.1 Pin Map

Connector selection

Use the project’s 80-position Molex CMC sealed automotive connector J1 (Molex 5022250801). The former DEUTSCH DRC 64-way proposal is obsolete. Existing implemented cavity assignments on J1 are the source of truth; unused positions remain reserved for expansion and must be sealed in the harness.

ECU PCB header: DRC23-64PAA
Right-angle, through-hole PCB mounting
64 positions in four rows on 4.42 mm centers
Gold-plated contacts
Active TE product
DRC family operating range: -55 C to +125 C
DRC size-20 contacts are rated up to 7.5 A; size-16 contacts are rated up to 13 A where supported by the selected insert

A 40-position connector is too small once separate power grounds, sensor grounds, configurable VR/Hall inputs, eight injectors, eight coils, three relays, and useful expansion are included. The 64-position header provides 51 assigned/reserved functions and 13 unused cavities.

Mechanical hold point: the mating plug housing, backshell, terminal series, cavity numbering viewed from the harness side, key code, and exact PCB footprint must be confirmed from the selected TE drawing before schematic capture or PCB placement. The electrical allocation below numbers cavities 1-64 but does not assume a physical row orientation.

Molex CMC cavity allocation

Power, grounds, and sensor supplies

Table

Cavity	Net	Function	Harness guidance
1	VBAT_RAW	Permanent battery input	Fused near battery, 18-16 AWG
2	IGN_SW	Ignition-switched wake input	Protected sense input, not main ECU power
3	PWR_GND_A	Injector-driver power ground	18-16 AWG to engine/head ground
4	PWR_GND_B	Injector-driver power ground	18-16 AWG to engine/head ground
5	PWR_GND_C	Power-entry and relay-driver ground	18-16 AWG
6	LOGIC_GND	Logic and coil-trigger reference	Keep separate in harness from noisy loads
7	SENSOR_GND_A	TPS/MAP sensor return; external MAP pin A	Do not connect to chassis in harness
8	SENSOR_GND_B	Temperature/O2 sensor return	Do not connect to chassis in harness
9	SENSOR_5V_A	Protected 5 V sensor supply	TPS, MAP, Hall sensors
10	SENSOR_5V_B	External MAP pin C, protected 5 V reference	Sensor supply

Analog and timing inputs

Table

Cavity	Net	Teensy pin	Function
11	TPS_IN	14 / A0	Throttle-position input
12	MAP_IN	15 / A1	External GM-style MAP pin B; 40-304 kPa absolute, protected/scaled for 3.3 V ADC
13	CLT_IN	16 / A2	Coolant-temperature input
14	IAT_IN	17 / A3	Intake-air-temperature input
15	WBO2_IN	18 / A4	External wideband controller 0-5 V input through divider/protection
16	VBAT_SENSE	19 / A5	Protected and divided battery measurement
17	AUX_AN1	20 / A6	Spare protected analog input
18	AUX_AN2	21 / A7	Spare protected analog input
19	CRANK_POS	0	Conditioned crank input from selectable VR/Hall front end
20	CRANK_NEG	-	VR return or Hall sensor return into conditioner
21	CAM_POS	1	Conditioned cam input from selectable VR/Hall front end
22	CAM_NEG	-	VR return or Hall sensor return into conditioner
23	VSS_IN	42	Protected vehicle-speed sensor pulse input
24	AUX_DIG1	-	Spare protected switched/digital input

Crank and cam connector pins go to their conditioning circuits, not directly to the Teensy. For Hall mode, POS is the signal and NEG is the dedicated sensor return; SENSOR_5V_A provides Hall power. For VR mode, POS and NEG are the differential sensor pair.

Injector outputs

Table

Cavity	Net	Teensy pin	Driver channel
25	INJ_1	2	TLE9104 A, channel 1
26	INJ_2	3	TLE9104 A, channel 2
27	INJ_3	4	TLE9104 A, channel 3
28	INJ_4	5	TLE9104 A, channel 4
29	INJ_5	6	TLE9104 B, channel 1
30	INJ_6	7	TLE9104 B, channel 2
31	INJ_7	8	TLE9104 B, channel 3
32	INJ_8	9	TLE9104 B, channel 4

The table lists the Teensy command pin associated with each output. The connector cavity is physically connected to the TLE9104 power output, never directly to the Teensy.

Smart-coil trigger outputs

Table

Cavity	Net	Teensy pin	Buffer channel
33	COIL_TRIG_1	24	AHCT244 channel 1
34	COIL_TRIG_2	25	AHCT244 channel 2
35	COIL_TRIG_3	26	AHCT244 channel 3
36	COIL_TRIG_4	27	AHCT244 channel 4
37	COIL_TRIG_5	28	AHCT244 channel 5
38	COIL_TRIG_6	29	AHCT244 channel 6
39	COIL_TRIG_7	30	AHCT244 channel 7
40	COIL_TRIG_8	31	AHCT244 channel 8

These are protected 0-5 V logic outputs for smart coils with internal igniters. They must not be connected to dumb coil primaries.

Relay and expansion outputs

Table

Cavity	Net	Teensy pin	Function
41	FUEL_PUMP_RELAY	32	Low-side external relay-coil control
42	FAN_RELAY_1	33	Low-side fan-relay control
43	FAN_RELAY_2	34	Low-side fan-relay control
44	AUX_LS_OUT1	-	Spare protected TLE8108 low-side output
45	AUX_LS_OUT2	-	Spare protected TLE8108 low-side output
46	AUX_LS_OUT3	-	Spare protected TLE8108 low-side output
47	AUX_LS_OUT4	-	Spare protected TLE8108 low-side output
48	AUX_LS_OUT5	-	Spare protected TLE8108 low-side output

Spare low-side channels are initially disabled and may later control relays or small solenoids within the driver's current and clamp-energy limits.

Future interfaces and reserved cavities

Table

Cavity	Net	Function
49	CAN_H	Protected external CAN high line from TJA1049T/3 transceiver
50	CAN_L	Protected external CAN low line from TJA1049T/3 transceiver
51	TACH_OUT	Protected configurable tachometer pulse output
52	SPEEDO_OUT	Protected configurable speedometer pulse output; Teensy GPIO43 command
53	AUX_AN3	Reserved analog input
54	AUX_AN4	Reserved analog input
55	SENSOR_5V_SPARE	Reserved protected 5 V supply contact
56	SENSOR_GND_SPARE	Reserved sensor-ground contact
57	LOGIC_GND_SPARE	Reserved logic-ground contact
58	PWR_GND_D	Additional power-ground contact
59	NC	No connection
60	NC	No connection
61	NC	No connection
62	NC	No connection
63	NC	No connection
64	NC	No connection

Unused cavities must be fitted with the correct sealing plugs in the harness connector.

Teensy 4.1 pin allocation

Pins 0-41 use the normal socket rows. GPIO42 and GPIO43 are allocated as the two additional exposed outer-edge solder pads for the VSS and speedometer signals; the ECU carrier/socket footprint must bring these two pads out with spring contacts, castellated capture, or short soldered jumpers. Inner expansion pads 44-54 remain reserved and unused. GPIO42/43 are digital interrupt-capable, and both expose FlexPWM1.1 timer capability; firmware should use a GPIO interrupt/capture path for VSS and a timer-driven output compare or scheduled GPIO toggle for SPEEDO_OUT so CAN1 remains fixed on GPIO22/23.

Table

Teensy pin	Assignment	Type / reason
0	CRANK_CAPTURE	Conditioned crank timing input; all Teensy digital pins support interrupts
1	CAM_CAPTURE	Conditioned cam timing input
2-9	INJ_CMD_1 through INJ_CMD_8	Eight direct injector timing commands
10	TACH_OUT_CMD	Tachometer pulse command to protected low-side output stage
11	SPI_MOSI	Shared output-driver diagnostic SPI bus
12	SPI_MISO	Shared output-driver diagnostic SPI bus
13	SPI_SCK	Shared output-driver diagnostic SPI bus; onboard LED interaction must be considered
14 / A0	ADC_TPS	Protected 0-3.3 V ADC input
15 / A1	ADC_MAP	Protected 0-3.3 V ADC input
16 / A2	ADC_CLT	Thermistor-divider ADC input
17 / A3	ADC_IAT	Thermistor-divider ADC input
18 / A4	ADC_WBO2	Divided/protected wideband input
19 / A5	ADC_VBAT	Divided/protected battery monitor
20 / A6	ADC_AUX1	Spare protected analog input
21 / A7	ADC_AUX2	Spare protected analog input
22	CAN1_TX	FlexCAN1 transmit to TJA1049T/3 TXD; definitive net `CAN1_TX_GPIO22`
23	CAN1_RX	FlexCAN1 receive from TJA1049T/3 RXD; definitive net `CAN1_RX_GPIO23`
24-31	COIL_CMD_1 through COIL_CMD_8	Eight smart-coil timing commands to 5 V buffer
32	FUEL_PUMP_CMD	Relay-driver input
33	FAN1_CMD	Relay-driver input
34	FAN2_CMD	Relay-driver input
35	COIL_ENABLE_N_CMD	Requests coil-buffer enable through safety gating
36	INJECTOR_ENABLE_CMD	Requests both injector IC enables through safety gating
37	DRIVER_RESET_N	Resets output-driver diagnostics and forces safe state
38	SPI_CS_INJ_A	Injector driver A chip select
39	SPI_CS_INJ_B	Injector driver B chip select
40	SPI_CS_RELAY	Relay driver chip select
41	DRIVER_FAULT_N	Hardware-combined active-low fault input from output stages
42	VSS_CAPTURE	Vehicle-speed sensor frequency input after conditioning; interrupt/capture input
43	SPEEDO_OUT_CMD	Speedometer pulse command to protected low-side output stage; timer-capable output

CAN 2.0 interface allocation and resolved pin map

Transceiver: NXP TJA1049T/3 (AEC-Q100), powered from 5 V with VIO at 3.3 V for direct Teensy logic compatibility.
External harness nets: cavity 49 = CAN_H; cavity 50 = CAN_L. These reuse the two previously reserved CAN cavities and do not alter any existing connector function.
Protection: Nexperia PESD2CANFD27V-UX (AEC-Q101) is connected from both bus lines to ground and must be placed at the Deutsch connector.
Termination: R48 is 120 ohm in series with normally-open solder jumper JP1 between CAN_H and CAN_L. Leave JP1 open unless this ECU is at a physical end of the CAN bus; bridge JP1 only when local termination is required.
Safe state: R47 pulls CAN_STANDBY high to 3.3 V, so the transceiver defaults to Standby while the MCU is absent or resetting. Firmware must drive STB low for Normal mode.

The conflict is resolved without changing CAN hardware: FlexCAN1 stays on GPIO22 TX and GPIO23 RX. VSS_CAPTURE moves to GPIO42 and SPEEDO_OUT_CMD moves to GPIO43. Pins 42/43 are the selected exposed outer-edge pads and provide the required GPIO interrupt and timer behavior; no injector, coil, crank/cam, diagnostic SPI, relay, tach, USB, or reserved inner-expansion allocation is displaced. The schematic endpoint nets are definitively CAN1_TX_GPIO22 and CAN1_RX_GPIO23. No Teensy/socket component is present in the current schematic, so these nets currently terminate at the transceiver; physical connection from those named nets to socket GPIO22/23 remains part of the later MCU block. Likewise, the later MCU block must connect the conditioned VSS endpoint to GPIO42 and the protected speedometer command stage to GPIO43.

Safety and electrical rules

Teensy 4.1 I/O is not 5 V tolerant. Every external input must be conditioned and clamped to the 3.3 V domain.
The selected external MAP sensor may produce up to 5.044 V. Its cavity-12 input network must attenuate and clamp this safely below 3.3 V at the Teensy ADC under tolerance and transient conditions.
Remove all onboard MAP sensor, hose-barb, vacuum-port, and MAP edge-keepout requirements from the PCB layout.
Teensy VIN accepts 3.6-5.5 V. Power it from the ECU's protected 5 V rail, not directly from vehicle battery.
Cut the Teensy VUSB-to-VIN link so USB can be connected while the ECU is externally powered without back-feeding the computer.
The Teensy 3.3 V output has a 250 mA recommended external-load limit. Driver logic and sensor loads should be included in the rail budget; use a separate automotive 3.3 V regulator if margin is inadequate.
Hardware pull-downs must hold all injector and relay commands OFF while the Teensy is absent or resetting.
The smart-coil buffer output-enable pins must default disabled with pull-ups and be controlled through watchdog/reset safety logic, not firmware alone.
DRIVER_FAULT_N may combine open-drain fault outputs. SPI is still used to identify the individual device and channel fault.
VSS input conditioning must support configurable Hall/open-collector sensors and a protected 12 V pulse input; no vehicle signal connects directly to GPIO42.
TACH_OUT and SPEEDO_OUT use protected low-side/open-collector stages so their pulse rate and scaling can be configured in firmware for different dashboards.
USB remains a separate board-accessible connector and is not routed through the Deutsch harness connector.
CAN termination is normally disconnected. Bridge JP1 only at a bus endpoint; never enable more than two 120 ohm terminators on one CAN segment.

Sources and verification status

PJRC Teensy 4.1 official pinout and pulse/PWM documentation: digital GPIO interrupt capability; GPIO42/43 FlexPWM1.1 capability; VIN 3.6-5.5 V; 3.3 V external load recommendation; VUSB isolation instruction; and no 5 V-tolerant I/O.
Allocation audit: expanding the ranges in the Teensy table yields exactly one assignment per GPIO0-43; GPIO44-54 remain reserved, with no duplicate GPIO assignments.
TE Connectivity DRC23-64PAA product data: active 64-position, four-row, right-angle, through-hole, sealed DRC PCB header with gold contacts and 4.42 mm centerline.
TE DRC family data: environmentally sealed family, -55 C to +125 C range, high-pin-count wire-to-board options.

The logical allocation is ready for schematic capture. Exact connector footprint and cavity orientation remain blocked until the TE customer drawing and chosen mating plug/key code are fixed.

Connector selection
Molex CMC cavity allocation
Power, grounds, and sensor supplies
Analog and timing inputs
Injector outputs
Smart-coil trigger outputs
Relay and expansion outputs
Future interfaces and reserved cavities
Teensy 4.1 pin allocation
CAN 2.0 interface allocation and resolved pin map
Safety and electrical rules
Sources and verification status