Home › Tuning › Swap tune checklist

LS swap tune checklist

What has to change in a donor computer before the swap will run and drive right, and the parts that have to match it.

What does my tune need? →

In the tune

• VATS: delete it, or the engine won't start.
• Injectors and MAF: match the injector size and MAF scaling to what's installed.
• Transmission: match the transmission settings to what's bolted on.
• Donor leftovers: emissions monitors and speed limiters from the donor are still there.
• AFM: PCM must be recalibrated to stop commanding deactivation; aftermarket cams also need idle, fuel, spark and torque-model changes.

Source summary: Every donor PCM needs reprogramming: delete VATS (or the engine will not start), match injector size and MAF scaling, and match transmission settings; emissions monitors and speed limiters from the donor are also present.

Parts that must match the computer

• Crank reluctor: 24x (Gen III: LS1, LS6, LQ4, LQ9, Vortec trucks through 2006) uses a 1x cam sensor; 58x (Gen IV: LS3, LS7, L76, L92, 2007+ Vortec trucks, 2007+ LS2) uses a 4x cam sensor. Exception: 2005–06 LS2s are 24x, so they need a 24x harness and computer. PCM, harness and sensors must match; a Gen III PCM on a 58x engine needs a conversion box.
• How to tell: Crank reluctor is 24x or 58x; the ECU must match. Tell by the crank sensor (behind the starter): early black 24x, later gray 58x.
• Sensors: Gen III: black crank sensor, cam sensor at the rear of the block. Gen IV: gray crank sensor, front-mounted cam sensor, EV6-style injectors, six-pin drive-by-wire throttle.
• Throttle: Drive-by-cable: throttle opened mechanically (early Gen III trucks, Camaro LS1). Drive-by-wire: PCM opens the throttle from a pedal-position sensor (all Gen IV). A DBW swap needs the pedal wired and calibrated. (PSI also says "most LS1/LS6" are DBW; C5 Corvette LS1 was DBW while F-body LS1 was cable; treat per-application)
• Not an LS: Gen II LT1/LT4 (1992–1996) are not LS engines: cable throttle, EV1 injectors, different harnesses.

What the computer does

The PCM reads crank, cam, MAF, coolant, IAT and O2 sensors to control fuel, spark and idle (and shifts on automatics); on drive-by-wire engines it also controls the throttle.

What the sources say

Paraphrased from the linked sources (30 points). Specifics depend on your computer and operating system.

Show all

• E92; LT4; 2015-2020: The Chevrolet Performance LT4 E-Rod instruction sheet specifies a tachometer output of four pulses per engine revolution as a square wave, and notes a 5,000-ohm pull-up resistor may be needed for compatibility with some tachometers. Chevrolet Performance
• E92; LT4; 2015-2020: The LT4 E-Rod controller provides a vehicle-speed output intended for self-scaling speedometers, but it requires a variable-reluctance speed sensor on the transmission to function. Chevrolet Performance
• 0411, 1181; LM7, LQ4, LQ9, LS1; 1999-2007: The official segment swapper copies transmission calibration data from a donor file to a recipient file only when both files share the same main operating-system number, and the full write is what installs the transferred transmission data. HP Tuners
• 0411, 1181; LM7, LQ4, LQ9; 1999-2007: A proper 4L60E-to-4L80E segment swap moves both the transmission segment and the transmission-diagnostics segment from the donor file. HP Tuners
• 0411, 1181; LM7, LQ4, LQ9; 1999-2007: The segment-swapped transmission calibration requires a full write to the controller to take effect; a calibration-only write does not install it. HP Tuners
• 0411, 1181; LM7, LQ4, LQ9; 1999-2007: The donor file for a segment swap should come from a factory application similar to the swap, and its operating system should already support the desired transmission. HP Tuners
• E38; LS2, LS3, L96; 2006-2015: On the E38, a VATS removal uses the Write-VIN/Tunerlock/VATS flash routine, which differs from other modules where a write-entire generally handles tuner-lock and VATS changes. HP Tuners
• 0411; LM7, LQ4, LQ9, L31; 1999-2002: The 12200411 service-number PCM is the P01-generation Gen III controller; 0411 units sourced from different factory applications can function once loaded with a calibration matched to the swap. GM Truck Central (archived)
• 0411; LM7, LQ4, LQ9; 1999-2002: No single donor application of the 0411 is inherently better; any 0411 can run a swap when flashed with the right tune. GM Truck Central (archived)
• 0411; LM7, LQ4, LQ9, LS1; 1999-2002: The 0411 hardware can operate both drive-by-cable and drive-by-wire throttles, but the calibration must be configured to match the throttle type installed. Chevy Hardcore
• 0411, 1181; LM7, LQ4, LQ9; 1999-2007: A calibration written for a cable-operated engine cannot operate a drive-by-wire throttle; the PCM needs a complete operating-system reflash matching the throttle architecture. LSX Magazine
• 0411; LM7, LQ4, LQ9, LS1; 1999-2002: The 0411 requires the matching 1999-2002 truck Throttle Actuator Control module for drive-by-wire; the visually identical 1997-2004 Corvette TAC module carries a different part number and is not interchangeable. LS Engine DIY / CarTech
• 0411, 1181; LM7, LQ4, LQ9; 1999-2007: 1999-2002 truck electronic-throttle systems use all three accelerator-pedal position signals, while 2003 and later systems use only two of the three pedal sensors. LS Engine DIY / CarTech
• 0411, 1181; LM7, LQ4, LQ9; 1999-2007: The 2003-up Gen III throttle body, TAC module and PCM are not backward compatible with 1999-2002 equipment, so pedal, module and throttle must come from a matched year range. LS Engine DIY / CarTech
• 0411; LM7, LQ4, LQ9, LS1; 1999-2002: Not every Gen III PCM carries idle-air-control driver hardware; the 12200411 is the recommended service number for cable-throttle swaps because its hardware and availability are known. LSX Magazine (Power Automedia)
• 0411; LS1; 1999-2003: 0411 PCMs found in 1999-2003 Corvettes left the factory set up for drive-by-wire only, so they must be reprogrammed before use in a cable-throttle swap. LSX Magazine (Power Automedia)
• 0411; L31; 2002: A 2002 Chevrolet Express van operating system 12212156 is a common 0411 base file for Vortec L31 conversions because it was factory-built for the van application. GM Truck Central (archived)
• 0411; L31, LM7, LQ4; 1999-2002: A typical 0411 swap base calibration disables VATS, suppresses alternator/generator fault codes that the swap harness does not wire, adjusts fuel-tank-pressure and post-catalyst O2 diagnostics to the installed hardware, and carries the correct VIN. GM Truck Central (archived)
• 0411, 1181; LM7, LQ4, LQ9, LS1; 1999-2007: A swap tune must correct the calibration for the actual injector flow rates, volumetric efficiency, spark advance, axle ratio and the presence or absence of EGR, EVAP and secondary-air devices. GM Truck Central (archived)
• 0411; LM7, LQ4, LQ9, L31; 1999-2002: Example 0411 swap base files exist for 4L60E 2WD and 4WD, 4L80E 2WD and 4WD, and manual-transmission combinations. GM Truck Central (archived)
• E40; LS2; 2005-2006: The E40 is the short-lived 2005-2006 Gen IV controller for 24x-reluctor engines; it integrated throttle-actuator control into the ECM itself, eliminating the separate TAC module of Gen III. LSX Magazine (Power Automedia)
• E40; LS2; 2005-2006: The E40 pairs only with the 90mm silver-blade four-bolt throttle body; the visually similar gold-blade units are not electronically compatible. LSX Magazine (Power Automedia)
• E40; LS2; 2005-2006: The E40 carries tall black plus short blue/gray connectors and the controller appeared only in a narrow set of 2005-2006 applications such as the SSR, GTO, early Corvette, TrailBlazer SS and midsize SUVs, making used units comparatively scarce. LSX Magazine (Power Automedia)
• E40; LS2; 2005-2006: The E40 only controls the engine; transmission control moved to the separate T42 controller, an architecture that continues through Gen IV. LSX Magazine
• E40; LS2; 2005-2006: E40 hardware retains 24x crank triggering and is incompatible with later 58x hardware, so the engine's reluctor generation must match the controller. LSX Magazine (Power Automedia)
• E38, E67; LS2, LS3, LS7, L96, L92; 2006-2015: Gen IV engines generally moved to a 58-tooth crank wheel controlled by the E38 or E67, and the physical identifier is the crank sensor: black connectors on 24x sensors, gray on 58x. LSX Magazine
• 0411, 1181, E38, E67; LS2, LS3, LS7; 1999-2015: A Gen IV engine cannot be run by a Gen III controller without converting the reluctor wheel and adapting the cam sensor and throttle hardware. LSX Magazine
• E38, E67, E78; LS2, LS3, LS7, L96; 2006-2015: Gen IV controllers communicate over CAN bus, and the separate engine and transmission controllers must run compatible operating systems to exchange torque and speed data. LSX Magazine
• E38, E67; LS2, LS3, LS7, LS9, LSA, L96; 2006-2015: The E38 is a two-connector engine controller and the E67 a three-connector engine controller; the E67 offers wider capability and was used on factory-supercharged LS9 and LSA engines, making it attractive for boosted swaps. LSX Magazine (Power Automedia)
• E38, E67; LS3, L96, LS7, LSA; 2006-2015: E38/E67 gold-blade throttle bodies share a four-bolt pattern and six-pin connector but have different electronics: the LS truck 87mm and car 90mm bodies are not interchangeable with each other. LSX Magazine (Power Automedia)

← Do I need a tune? · Next: Tuning fundamentals → · What does my tune need?