CAN adapter for proper operation of Chrysler / Jeep / Dodge HEMI engine and transmission when swapped
Adapter for swapping a Chrysler / Dodge / Jeep HEMI 5.7 or SRT 6.1 engine (2005–2010) with a 545RFE or Mercedes NAG1 transmission into a vehicle with an analog instrument cluster — GAZelle, Nissan Patrol, Mitsubishi Delica, Pajero 2, L200 and others. It gives the engine and transmission everything they need over the CAN bus to run properly, and drives the stock cluster: speedometer, tachometer and the CHECK ENGINE, oil pressure, charging and reverse lamps. Set up in the GoSwap configurator from a phone over a USB cable: gear ratios, wheel circumference, where speed comes from — the transmission output shaft or a separate sensor, fine-tuning of the speedometer and tachometer. With NAG1, the configurator reads the gear ratios and wheel circumference from the transmission control unit by itself.
Red
+IGN — +12 V from the ignition switch — positive with the ignition on
Black
GND — chassis ground
White
CAN L — to CAN L of the HEMI engine control unit
Green
CAN H — to CAN H of the HEMI engine control unit
Gray
SPD — to the speedometer wire of the instrument cluster
Low-side output. If needed: if the stock speedometer runs from its own sensor — for example, on a Nissan Patrol from the transfer case — SPD is not connected.
Yellow
TACH — to the tachometer wire of the instrument cluster
Low-side output.
Orange
CHECK — to the CHECK ENGINE lamp of the cluster
Low-side output — switches to ground. Output polarity can be changed with a jumper.
Gray
OIL — to the oil pressure lamp of the cluster
Low-side output — switches to ground. Output polarity can be changed with a jumper.
Light gray
GEN — to the charge lamp of the cluster
No need to connect the alternator. Low-side output — switches to ground. Output polarity can be changed with a jumper.
Pink
R — to the reverse circuit (lights, camera)
Connect through a relay!
Low-side output — switches to ground. Output polarity can be changed with a jumper.
Light gray
SPD IN — to the speed sensor on the transmission output shaft
Optional: connected only if speed is taken from a separate sensor rather than over CAN. Active-high input. The input is enabled with the CAPT jumper.
Brown
GND — speed sensor ground
Optional: connected only together with a separate speed sensor SPD IN [11].
[—] — output switches to ground · [+] — input triggers from +12 V
Not used: 2, 4, 14, 16–24.
OUT [+] / [—] jumpers change the polarity of the output signal: [+] — the output supplies +12 V, [—] — it pulls the pin to ground.
From the factory all four outputs are soldered low-side: CHECK [7], OIL [8], GEN [9] and R [10] switch to ground. Resolder an output to high-side only if your lamp or relay is switched by positive.
Tap a channel and [+] / [—] — the photo shows where to solder
Do not solder both jumpers on the same channel!
Pin 11 works in one of two ways, chosen by a three-pad jumper on the bottom side of the board. CAPT is a frequency input: engine speed, vehicle speed. +5V is a 5 V output to power sensors. The middle pad is the pin itself: it is soldered either to the pad by the “+5V” label or to the other one. It is soldered at assembly for the specific adapter. The jumper is on boards from revision v5.1; v5 does not have it.
From the factory the jumper is in the CAPT position: SPD IN [11] is the speed sensor input. No need to change it.
The CAPT input is positive-triggered [+]: it captures the frequency of a signal that supplies a voltage. It does not see the wire being switched to ground.
From the factory the terminator is not soldered. The adapter connects to the HEMI engine bus — if the measurement shows 120 Ω, solder the CAN1 jumper.
The adapter is set up in the GoSwap app from a phone over a USB Type-C cable. Changes are sent to the adapter with the “APPLY” button at the bottom of the screen — the number on it shows how many settings have changed.
Connect the phone.
Install the GoSwap app — app page. Turn on the ignition, connect the phone and the adapter with a USB Type-C cable, choose “USB” in the app and tap “Connect”.
Open larger Transmission — EGS tab.
NAG1 transmission (Mercedes 722.6): at the bottom of the tab tap “Read settings from EGS”. The adapter reads the final drive ratio, wheel circumference, transfer case and speed source from the transmission control unit. New values are marked with an orange dot — check them and tap “APPLY”.
545RFE transmission: the final drive ratio and wheel circumference can be left as they are, speed source — CAN.
Speed source ANALOG — only with a separate output shaft sensor on the SPD IN [11] contact: a Hall sensor, 3 wires, 16 pulses per revolution. After “APPLY” the app restarts the adapter by itself.
Open larger Tachometer — TACH tab.
Start with a typical value: 33 for the cluster of a 4- or 8-cylinder car, 50 for a 6-cylinder one. Tap ▶ at the bottom of the screen — the “RPM” tile shows the engine speed. If the needle reads lower — “+”, higher — “−”, then “APPLY”.
Open larger Speedometer — SPD tab.
Only while driving: accelerate to a steady speed, 80–100 km/h, and compare the needle with the “GPS speed” tile above the setting — this is the speed from the phone's GPS. If the needle reads lower, tap “+”, higher — “−”, then “APPLY” and compare again.
If the cluster speedometer runs from its own sensor and SPD [5] is not connected — skip this step.
Open larger Check — LIVE tab.
The tiles show what the adapter receives and sends right now:
Open larger Hover or tap an element to see its function
The app is connected over the USB cable. Blue is on but red is not — the cable is in, the app is not connected.
On — speed is taken from the SPD IN [11] sensor (ANALOG source), off — over CAN. 10 flashes in a row — no connection to the engine or transmission: the CHECK and OIL lamps flash together, the needles are at zero, blue and red are off.
A USB cable is plugged in.
USB Type-C — for a phone with the GoSwap app: setup, firmware update, CAN bus recording for support. No CAN interface is needed.
Polarity of outputs OUT1…OUT4: [+] or [—].
Built-in 120 Ω resistor for the CAN1 or CAN2 bus. When to solder it — see “Jumpers”.
LED PWM1 and LED PWM2 are yellow, on v5.1 boards: they flash with the speedometer (PWM1) and tachometer (PWM2) signal. They light only if there is a pull-up on the cluster side. During a firmware update red, orange and blue light up in turn, in a circle.
