The THINKDIAG 2 is a genuine, confirmed upgrade over the original THINKDIAG, not just a refreshed model number. It adds CAN-FD protocol support the original does not have, a faster Bluetooth 5.0 connection, and a first-year software policy that is actually more generous than the original’s. For a modest premium, the THINKDIAG 2 is the better-documented choice for almost every buyer; the only reason to consider the original is if you find it at a meaningfully lower price and your vehicles predate CAN-FD entirely.

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The Short Answer

Best Overall for Almost Every Buyer: THINKCAR THINKDIAG 2, a confirmed upgrade with CAN-FD support and a faster Bluetooth 5.0 connection.

Best Budget Pick: Thinkcar THINKDIAG, the lowest entry price in Thinkcar’s bidirectional/coding lineup.

Two Buyer Scenarios

Any of your vehicles are 2020 or newer, especially GM: the THINKDIAG 2 is the only one of the two that can read them fully, via its confirmed CAN-FD support.

You work mostly on one brand and want the lowest ongoing software cost: the THINKDIAG 2’s single-brand renewal option makes its total cost of ownership potentially lower than the original THINKDIAG’s stacked renewal requirements, despite the higher upfront price.

Thinkcar THINKDIAG

The Thinkcar THINKDIAG confirms bidirectional control and ECU coding at the lowest entry price in Thinkcar’s coding-capable lineup, reading across twelve vehicle systems including ECM, ABS, SRS, and BMS through a compact Bluetooth dongle. IMMO key matching and AutoVIN identification come included. It lacks CAN-FD protocol support, which the THINKDIAG 2 confirms, and its two manufacturer software packages each require separate paid renewals after the first year, worth weighing against the small price gap to its successor.

Pros	Cons
Priced lower than the THINKDIAG 2	No CAN-FD protocol support, which the THINKDIAG 2 confirms
Bidirectional control and ECU coding confirmed, same core capability as the THINKDIAG 2
Lowest entry price in Thinkcar's bidirectional/coding lineup	Two separate manufacturer software packages each require their own paid renewal after year one, plus a separate renewal for reset-service software
IMMO key matching and AutoVIN included
Compact Bluetooth dongle, works with a standard phone app	Older Bluetooth v4.0, versus the THINKDIAG 2's Bluetooth 5.0
Reads across ECM, TCM, ABS, SRS, BCM, IMMO, BMS, TPMS, SAS, fuel, lighting and wiper systems

THINKCAR THINKDIAG 2

The THINKCAR THINKDIAG 2 adds confirmed CAN-FD protocol support for late-model GM and other post-2020 vehicles the original THINKDIAG can’t fully read, over a faster Bluetooth 5.0 connection. Named, specific active-test functions cover the radiator fan, throttle, windows, mirrors, and lights, with a full year of free software and functions included at activation. It’s priced somewhat higher than the original and remains phone-app dependent with no standalone screen, but a lower-cost single-brand renewal option is available once that first free year ends.

Pros	Cons
CAN-FD protocol support confirmed, covering late-model GM and other post-2020 vehicles the original cannot fully read	Priced somewhat higher than the original THINKDIAG
Bluetooth 5.0 for a faster, more stable connection
Named, specific active-test functions (radiator fan, throttle, windows, mirrors, lights)
1 year of free full software and functions with activation	Phone-app dependent, no standalone screen, same limitation as the original
Lower-cost single-brand renewal option available after the first free year
Vehicle compatibility with 120+ brands

THINKDIAG vs THINKDIAG 2 at a Glance

Specification	Thinkcar THINKDIAG	THINKCAR THINKDIAG 2
Price	$100-$150 range	$100-$150 range, at the higher end
Connectivity	Bluetooth v4.0	Bluetooth 5.0
Vehicle compatibility	1996+, up to 115 manufacturers	1996+, 120+ brands
CAN-FD support	Not offered	Confirmed, supports late-model GM and other post-2020 CAN-FD vehicles
Bidirectional control	Confirmed	Confirmed, named tests: radiator fan, throttle, windows, mirrors, lights
ECU coding	Confirmed, adaptive data for windows, lighting, HVAC	Confirmed, adaptive data after part replacement
Reset functions	15+ documented	15+ documented
Software policy	Two manufacturer packages free for year one; each requires a separate paid renewal, plus a separate paid renewal for reset-service software	1 year free full software/functions with activation; paid renewal after, with a lower-cost single-brand option available

CAN-FD: The Clearest Reason to Choose the THINKDIAG 2

This is the single biggest functional difference. The THINKDIAG 2 confirms CAN-FD protocol support, explicitly covering late-model GM and other post-2020 CAN-FD vehicles. The original THINKDIAG does not offer this at all. If any of your vehicles are 2020 or newer, particularly GM, this alone can decide the comparison.

Bluetooth Version: A Real, if Smaller, Upgrade

The THINKDIAG 2 uses Bluetooth 5.0, versus the original’s Bluetooth v4.0. In practice this means a faster, more stable connection, particularly in a shop environment with multiple wireless devices nearby.

Software and Subscription Policy: The THINKDIAG 2’s Terms Are More Favorable

This is a detail worth reading carefully rather than assuming both work the same way. The original THINKDIAG gives you two manufacturer software packages free for the first year, but each requires its own separate paid renewal afterward, and the reset-service software needs yet another separate paid renewal on top of that. The THINKDIAG 2 offers one year of free full software and functions with activation, and critically, its paid renewal includes a lower-cost option if you only need single-brand coverage going forward. For a DIYer who mostly works on one make, the THINKDIAG 2’s ongoing cost can end up lower even though the upfront price is somewhat higher.

Bidirectional Control: Both Confirmed, THINKDIAG 2 More Specifically Documented

Both devices confirm bidirectional control. The THINKDIAG 2’s documentation names specific active tests (radiator fan, throttle, windows, mirrors, lights); the original THINKDIAG’s bidirectional confirmation is not broken down into as many individually named functions, though the capability itself is equally confirmed.

ECU Coding: Confirmed on Both, Slightly Different Framing

Both support ECU coding. The original THINKDIAG’s coding is documented for adaptive data on windows, lighting and HVAC specifically. The THINKDIAG 2’s coding is documented more generally as adaptive data after part replacement. Neither documentation suggests one is meaningfully more capable than the other on coding specifically; the real difference between the two products remains CAN-FD.

Vehicle Compatibility: A Modest Increase

The original covers up to 115 manufacturers; the THINKDIAG 2 covers 120+. This is a small difference and unlikely to be decisive on its own for most buyers.

Reset Functions: Effectively Identical

Both document 15+ reset and maintenance functions (oil reset, ABS bleeding, TPMS reset and others). Neither has a documented advantage over the other here.

Frequently Asked Questions

Is the THINKDIAG 2 worth the extra cost over the original THINKDIAG?

For most buyers, yes. It adds confirmed CAN-FD support the original does not have, a faster Bluetooth 5.0 connection, and potentially lower ongoing software costs if you only need single-brand coverage.

Does the original THINKDIAG support CAN-FD?

No. CAN-FD support is confirmed only on the THINKDIAG 2.

Do both support ECU coding?

Yes, both confirm ECU coding, though documented with slightly different framing (windows/lighting/HVAC adaptive data on the original; general adaptive data after part replacement on the THINKDIAG 2).

Which has cheaper ongoing software costs?

Potentially the THINKDIAG 2, since it offers a lower-cost single-brand renewal option. The original THINKDIAG requires separate paid renewals for two manufacturer packages plus its reset-service software.

Which is better for a DIYer working on a single brand?

The THINKDIAG 2, mainly because of its single-brand renewal pricing option after the first free year.

Bottom Line

Choose the THINKCAR THINKDIAG 2 for the confirmed CAN-FD support, faster Bluetooth and better-structured renewal pricing, unless your vehicles are all pre-2020 and you find the original Thinkcar THINKDIAG at a meaningfully lower price. For more budget-focused bidirectional options, see our budget bidirectional scanner buying guide.

Affiliate Disclosure

SCG links to Amazon product pages for the scanners discussed above. SCG earns a commission on qualifying purchases made through these links.

Editorial Note

Every specification and capability claim above is sourced directly from the manufacturer’s own product pages, cross-checked against Amazon’s listing where applicable.