Jeep Diagnostic Scanners and Adapters

Written by the YOUCANIC technicians in Towson, Maryland, from the UCAN-II Pro coverage database and our own shop work. Updated October 24, 2026.

A 2018 or newer Jeep hides most of its control units behind a Security Gateway Module, so a parts store scanner sees engine codes and little else. The tools below are what we use in our own shop in Maryland to get behind that gateway, reach every module on a Jeep, bleed the brakes, relearn the transmission and clear the codes the dealer charges an hour of labor to read. The coverage database behind the UCAN-II Pro lists the JL, JK and J8 Wrangler, JT Gladiator, KL Cherokee, KK and KJ Liberty, WK Grand Cherokee, WS Wagoneer, MP and MK Compass and Patriot, BU and BV Renegade and XK Commander, with a basic engine, transmission, ABS and airbag set for Jeeps up to 2003. Pick by what you need to do, then read the gateway rule.

Which Scanner Do I Need For A Jeep?

CHECK ENGINE LIGHT ONLY

UCAN-GO

Reads and clears engine codes from your phone and gives you a live gauge dashboard. It does not see ABS, airbag, transmission or body modules, and it cannot get behind the gateway on a 2018 or newer Jeep. Right if the only light you care about is the engine one.

EVERY MODULE, EVERY SERVICE FUNCTION

UCAN-II Pro, new or open box

Full system, bidirectional, lifetime free updates, with the FCA 12+8 gateway adapter in the box. Reads and clears every control unit, runs active tests and the Jeep service functions: brake bleeding, transmission Quicklearn, throttle learn, tire size, occupant classification test, 4WD control and the body customizations. The tool to own if you keep a Jeep running.

ONE JOB THIS MONTH

Rent the UCAN-II Pro for a week

Same scanner, shipped both ways free, with a refundable deposit that comes back when the scanner does. For the one brake bleed, transmission relearn or airbag code you need done once. On a 2018 or newer Jeep add the 12+8 adapter to the rental order.

What The UCAN-II Pro Does On A Jeep

• ✓ Reads and clears codes in every control unit: 37 modules on a 2022 KL Cherokee and 38 on a 2022 WS Wagoneer, from the ABS, EPB and EPS to the air suspension, sway bar and hybrid control processor (the table below lists them)
• ✓ Bleed brakes in 2WD, 4WD and ABS only modes from the ABS module after a line, caliper or hydraulic unit replacement
• ✓ Quicklearn for the RFE transmissions and the non RFE routine, Clear Variable Line Pressure counters, Torque Converter Clutch break in, PCM Replaced
• ✓ Learn Electronic Throttle Control after a throttle body cleaning or battery disconnect, Reset Memory, Check PCM VIN and Check PCM Odometer
• ✓ Program Tire Size after a lift and bigger tires, 4WD Control, Trailer Tow Relay Outputs, Occupant Classification Module system verification test after seat work
• ✓ Body customizations: Activate DRL, Activate Front Fog Lamp Output, Horn Chirp Duration, Sound Horn On Lock, Illuminated Entry Time, Headlamps On With Wipers, Auto Door Lock and Unlock, Tilt Mirrors In Reverse, Easy Entry and Exit
• ✓ Diesel and heater routines: Compression Test, EGR Positioner, Fuel Leakage Quantity Test, High Pressure Pump and Boost Pressure Regulator on the engine module, Dosing Pump Prime and Output, Combustion Fan and Glow Pin on the cabin heater module
• ✓ ECU configure information and active tests on 30 plus modules each, from the ABS and PCM to the HVAC, sunroof and heated seats, plus event data and misfire data
• ✓ Live data with graphing and recording, plus TPMS: triggers the sensors and programs the U360 replacement sensor from the tablet

Service Functions By Job On A Jeep

On the tablet you pick the control unit, then the function category, then the routine. These are the routines the coverage database lists for Jeep, grouped by the job you are doing. Names are as they appear on the tablet. Coverage varies by platform and year, so check yours before you order.

What The Scanner Sees On A Jeep

Three entries pulled from the coverage database, with the control units the UCAN-II Pro lists on each. Every unit gets fault codes, live data and, where the database shows it, active tests, ECU configuration information and special functions.

Symptom, Then The Routine That Fixes It

• Spongy pedal after a brake line, caliper or hydraulic unit job: Bleed brakes ABS only, or the 2WD and 4WD routines, in the ABS module.
• Harsh or delayed shifts after a fluid and filter service on an RFE transmission: Quicklearn (RFE) in the TCM, then the Torque converter clutch (TCC) break-in where listed.
• High idle or stalling after a throttle body cleaning or a battery disconnect: Learn electronic throttle control (ETC) in the PCM.
• Speedometer and ABS off after a lift and bigger tires: Program tire size.
• Airbag light after seat or seat track work: Occupant classification module (OCM) system verification test.
• Fog lamps or daytime running lights dead after a retrofit: Activate front fog lamp output and Activate DRL in the BCM.

Frequently Asked Questions

I have a 2020 Wrangler JL. Do I need anything besides the scanner?

The FCA 12+8 adapter, and it is already in the UCAN-II Pro box. It plugs in behind the Security Gateway Module under the dash and the scanner then reaches every module. Without it, any aftermarket tool sees engine codes and nothing else on a 2018 or newer Jeep.

Will it relearn the transmission on my Grand Cherokee after a fluid service?

Yes. Quicklearn for the RFE transmissions and the non RFE routine are in the transmission module function list, along with the torque converter clutch break in and the variable line pressure counter reset. The transmission adaptation guide walks through it.

Can it bleed the ABS on my JK after I replaced a brake line?

Yes. Bleed Brakes 2WD, 4WD and ABS Only are listed for the ABS module, which cycles the valves so the air trapped in the hydraulic unit comes out. The ABS bleeding guide explains the sequence.

Does it program keys?

No. Key programming needs the Stellantis server through wiTECH. The UCAN-II Pro does diagnosis, live data, active tests, relearns and the service functions listed above.

Can I rent it for one job?

Yes. The rental is a one week rental plus a refundable deposit that comes back when the scanner does, shipped free both ways. The rental kit does not include the 12+8 adapter, so on a 2018 or newer Jeep add the adapter to the order and keep it. Most Jeep renters want a brake bleed, a transmission relearn or an airbag light cleared.

How do I know my exact Jeep and function are covered?

Use the coverage checker by year, platform and module, or call 1-888-959-4265, Monday to Friday 9 AM to 4 PM Eastern, and a technician will tell you plainly. If it does not do what you need, we will say so. Every scanner also comes with 31 day returns, no questions asked.

Working on a different make? See the scanners by make hub, the service functions explained one job at a time, and the step by step repair guides on youcanic.com.