Engine · GM

GM LS: what the engine asks of an ECU

Page data last updated 2 October 2026

The LS is the default swap engine for a reason: it is compact, plentiful and the aftermarket has made its peace with it. For an ECU, the badge matters less than the generation, because Gen III and Gen IV are triggered differently.

Gen III engines run a 24x crank wheel with a 1x cam. Gen IV engines run 58x with a 4x cam, apart from a few early LS2s that left the factory with the older pattern. The variants below say which is which, and each row says where the fact came from.

Where this comes from

Some items on this page are cited from Wikipedia and from ECU manufacturers such as Haltech, not from the engine's maker. Each row names its source, and a † marks a row that is crowdsourced. Always check your specific sensors and manuals where you have them.

A figure like 58x is pulses per crank revolution from one sensor. It is a rate, not a sensor count, and it does not say whether the sensor is VR or Hall. The planner reads sensor type, cam sensor count and variable cams from the cited text. Where the text does not settle one, the row says so: check your sensor.

What GM says about the trigger pattern

  • Gen IV with electronic throttle (GM: typically 2006 and newer)4, 5

    Crank wheel 58xCam 4x indexing, sensor at the front, grey crank connector

  • Earlier engines5

    Crank wheel 24xCam 1x, sensor at the rear, black connectors

  • Early LS25

    Crank wheel 24xCam 1x, sensor at the front, black connectors

What GM wires to the engine

GM's harness list for its crate control kit is the plainest statement of what an LS needs wired. Counted from it:4

Fuel injectors8, two-pin connectors, one per cylinder
Ignition coilsOne coil per cylinder, on two eight-pin coil blocks
Crankshaft position sensorOne, three-pin connector (power, ground, signal)
Camshaft position sensorOne, three-pin connector (power, ground, signal)
Electronic throttleOne six-pin throttle body, plus a six-pin accelerator pedal
Knock sensors2, two-pin connectors
MAP and MAFMAP on three pins, MAF on five
Oxygen sensors2, five-pin connectors

GM's engine figures

LS3 LS7
Type6.2L Gen IV small block V87.0L Gen IV small block V8
Displacement376 cu in427 cu in
Bore x stroke4.065 x 3.622 in4.125 x 4.0 in
Compression10.7:111.0:1
Maximum engine speed6,600 rpm7,000 rpm
Firing order1-8-7-2-6-5-4-31-8-7-2-6-5-4-3
Fuel pressure58 psi (engine sheet), 60 psi (control kit)58 psi
Source1, 23

Variants

LS1 (Gen3 5.7 alum)

Engine
8 cylinders, V layout6
Aspiration
Naturally aspirated6
Fuel injection
Port injection, sequential7
Ignition
COP, smart coils (igniter built in)7
Crank trigger
24x reluctor (Hall-digital, 12V)8
Cam trigger
1x Hall8
Cams and variable timing
1 camshaft; variable timing: none6
Firing order
1-8-7-2-6-5-4-36
Factory ECU
411/P01 PCM †
Notes
Gen III. The coils are smart, with the igniter built in.7

† Crowdsourced. This figure comes from builder and parts-supplier pages, not from the engine's maker or an ECU manufacturer. Treat it as a lead, then check your specific sensors and manuals.

How the planner reads the trigger text

Crank sensor type
Hall
Cam sensor type
Hall
Cam position sensors
1
Variable cams
0

Wire-in ECUs that cover it: 9 as they come, 20 more with add-on modules. The count is the planner's, worked out from the pin tables.

Fits as it is 9
Fits with add-ons 20

Plan a build around the LS1 (Gen3 5.7 alum)

LS6 (Gen3 5.7 alum)

Engine
8 cylinders, V layout6
Aspiration
Naturally aspirated6
Fuel injection
Port injection, sequential7
Ignition
COP, smart coils (igniter built in)7
Crank trigger
24x reluctor (Hall-digital, 12V)8
Cam trigger
1x Hall8
Cams and variable timing
1 camshaft; variable timing: none6
Firing order
1-8-7-2-6-5-4-36
Factory ECU
411 PCM †
Notes
Gen III. Electrically identical to the LS1.6

† Crowdsourced. This figure comes from builder and parts-supplier pages, not from the engine's maker or an ECU manufacturer. Treat it as a lead, then check your specific sensors and manuals.

How the planner reads the trigger text

Crank sensor type
Hall
Cam sensor type
Hall
Cam position sensors
1
Variable cams
0

Wire-in ECUs that cover it: 9 as they come, 20 more with add-on modules. The count is the planner's, worked out from the pin tables.

Fits as it is 9
Fits with add-ons 20

Plan a build around the LS6 (Gen3 5.7 alum)

LQ4/LQ9 (Gen3 6.0 iron)

Engine
8 cylinders, V layout6
Aspiration
Naturally aspirated6
Fuel injection
Port injection, sequential7
Ignition
COP, smart coils (igniter built in)7
Crank trigger
24x reluctor (Hall-digital, 12V)8
Cam trigger
1x Hall8
Cams and variable timing
1 camshaft; variable timing: none6
Firing order
1-8-7-2-6-5-4-36
Factory ECU
411 PCM †
Notes
Iron truck block. The LQ9 is a higher-compression LQ4, and the two are electronically identical.6

† Crowdsourced. This figure comes from builder and parts-supplier pages, not from the engine's maker or an ECU manufacturer. Treat it as a lead, then check your specific sensors and manuals.

How the planner reads the trigger text

Crank sensor type
Hall
Cam sensor type
Hall
Cam position sensors
1
Variable cams
0

Wire-in ECUs that cover it: 9 as they come, 20 more with add-on modules. The count is the planner's, worked out from the pin tables.

Fits as it is 9
Fits with add-ons 20

Plan a build around the LQ4/LQ9 (Gen3 6.0 iron)

LS2 (Gen4 6.0 alum)

Engine
8 cylinders, V layout6
Aspiration
Naturally aspirated6
Fuel injection
Port injection, sequential9
Ignition
COP, smart coils (igniter built in)9
Crank trigger
58x reluctor (Hall, 12V)9
Cam trigger
4x Hall9
Cams and variable timing
1 camshaft; variable timing: none6
Firing order
1-8-7-2-6-5-4-39
Factory ECU
E40 (2005) / E38 (2006+) †
Notes
The first Gen IV car engine. One Hall cam sensor. †

† Crowdsourced. This figure comes from builder and parts-supplier pages, not from the engine's maker or an ECU manufacturer. Treat it as a lead, then check your specific sensors and manuals.

How the planner reads the trigger text

Crank sensor type
Hall
Cam sensor type
Hall
Cam position sensors
1
Variable cams
0

Wire-in ECUs that cover it: 9 as they come, 20 more with add-on modules. The count is the planner's, worked out from the pin tables.

Fits as it is 9
Fits with add-ons 20

Plan a build around the LS2 (Gen4 6.0 alum)

LS2 (Gen4 6.0 alum, early 24x/1x)

Engine
8 cylinders, V layout6
Aspiration
Naturally aspirated6
Fuel injection
Port injection, sequential9
Ignition
COP, smart coils (igniter built in)9
Crank trigger
24x reluctor (Hall-digital)10 still to verify
Cam trigger
1x Hall (front cover)10 still to verify
Cams and variable timing
1 camshaft; variable timing: none6
Firing order
1-8-7-2-6-5-4-39
Notes
A few early LS2s left the factory with a 24x crank wheel and a 1x cam wheel instead of 58x and 4x. On these the cam sensor may sit in the front cover rather than at the back of the block, so a Gen III-style harness needs its cam sensor lead extended (Holley 199R10555 rev 17, p12, section 8.1). Check which wheel your engine has before wiring: the 24x and 58x sensors are not interchangeable.10

How the planner reads the trigger text

Crank sensor type
Hall
Cam sensor type
Hall
Cam position sensors
1
Variable cams
0

Wire-in ECUs that cover it: 9 as they come, 20 more with add-on modules. The count is the planner's, worked out from the pin tables.

Fits as it is 9
Fits with add-ons 20

Plan a build around the LS2 (Gen4 6.0 alum, early 24x/1x)

LS3 (Gen4 6.2 alum, car)

Engine
8 cylinders, V layout6
Aspiration
Naturally aspirated6
Fuel injection
Port injection, sequential9
Ignition
COP, smart coils (igniter built in)9
Crank trigger
58x reluctor (Hall, 12V)9
Cam trigger
4x Hall9
Cams and variable timing
1 camshaft; variable timing: none6 †
Firing order
1-8-7-2-6-5-4-39
Factory ECU
E38 †
Notes
Car engine, no VVT. The L99 sibling, fitted to automatic cars, adds VVT and AFM and has its own preset. †

† Crowdsourced. This figure comes from builder and parts-supplier pages, not from the engine's maker or an ECU manufacturer. Treat it as a lead, then check your specific sensors and manuals.

How the planner reads the trigger text

Crank sensor type
Hall
Cam sensor type
Hall
Cam position sensors
1
Variable cams
0

Wire-in ECUs that cover it: 9 as they come, 20 more with add-on modules. The count is the planner's, worked out from the pin tables.

Fits as it is 9
Fits with add-ons 20

Plan a build around the LS3 (Gen4 6.2 alum, car)

L76 (Gen4 6.0 alum)

Engine
8 cylinders, V layout6
Aspiration
Naturally aspirated6
Fuel injection
Port injection, sequential9
Ignition
COP, smart coils (igniter built in)9
Crank trigger
58x reluctor (Hall, 12V)9
Cam trigger
4x Hall9
Cams and variable timing
1 camshaft; variable timing: 1 (single-phaser (int+exh together)); cylinder deactivation6 †
Firing order
1-8-7-2-6-5-4-39
Factory ECU
E38/E67 †
Notes
VVT and AFM (also called DoD) on the truck version. On Holden builds (VE Commodore, G8 GT) AFM was disabled, except on the 2008 G8 GT and the 2009 Holden cars with the 6L80 automatic. Cam phasing is credited to the truck version.6

† Crowdsourced. This figure comes from builder and parts-supplier pages, not from the engine's maker or an ECU manufacturer. Treat it as a lead, then check your specific sensors and manuals.

How the planner reads the trigger text

Crank sensor type
Hall
Cam sensor type
Hall
Cam position sensors
1
Variable cams
1

Wire-in ECUs that cover it: 9 as they come, 20 more with add-on modules. The count is the planner's, worked out from the pin tables.

Fits as it is 9
Fits with add-ons 20

Plan a build around the L76 (Gen4 6.0 alum)

L92 (Gen4 6.2 alum)

Engine
8 cylinders, V layout6
Aspiration
Naturally aspirated6
Fuel injection
Port injection, sequential9
Ignition
COP, smart coils (igniter built in)9
Crank trigger
58x reluctor (Hall, 12V)9
Cam trigger
4x Hall9
Cams and variable timing
1 camshaft; variable timing: 1 (single-phaser)6
Firing order
1-8-7-2-6-5-4-39
Factory ECU
E38 †
Notes
VVT, no AFM. Fitted to the Escalade, Denali and Tahoe. The L94 sibling adds AFM. †

† Crowdsourced. This figure comes from builder and parts-supplier pages, not from the engine's maker or an ECU manufacturer. Treat it as a lead, then check your specific sensors and manuals.

How the planner reads the trigger text

Crank sensor type
Hall
Cam sensor type
Hall
Cam position sensors
1
Variable cams
1

Wire-in ECUs that cover it: 9 as they come, 20 more with add-on modules. The count is the planner's, worked out from the pin tables.

Fits as it is 9
Fits with add-ons 20

Plan a build around the L92 (Gen4 6.2 alum)

LY6/L96 (Gen4 6.0 iron)

Engine
8 cylinders, V layout6
Aspiration
Naturally aspirated6
Fuel injection
Port injection, sequential9
Ignition
COP, smart coils (igniter built in)9
Crank trigger
58x reluctor (Hall, 12V)9
Cam trigger
4x Hall9
Cams and variable timing
1 camshaft; variable timing: 1 (single-phaser)6 †
Firing order
1-8-7-2-6-5-4-39
Factory ECU
E38 †
Notes
Iron 6.0 litre truck engine with VVT. The L96 (2010 on) adds FlexFuel. †

† Crowdsourced. This figure comes from builder and parts-supplier pages, not from the engine's maker or an ECU manufacturer. Treat it as a lead, then check your specific sensors and manuals.

How the planner reads the trigger text

Crank sensor type
Hall
Cam sensor type
Hall
Cam position sensors
1
Variable cams
1

Wire-in ECUs that cover it: 9 as they come, 20 more with add-on modules. The count is the planner's, worked out from the pin tables.

Fits as it is 9
Fits with add-ons 20

Plan a build around the LY6/L96 (Gen4 6.0 iron)

LSA (Gen4 6.2 alum, S/C)

Engine
8 cylinders, V layout6
Aspiration
Supercharged6
Fuel injection
Port injection, sequential9
Ignition
COP, smart coils (igniter built in)9
Crank trigger
58x reluctor (Hall, 12V)9
Cam trigger
4x Hall9
Cams and variable timing
1 camshaft; variable timing: none6 †
Firing order
1-8-7-2-6-5-4-39
Factory ECU
E67 †
Notes
Eaton 1.9 litre four-lobe Roots supercharger. CTS-V and ZL1. No VVT or AFM.6

† Crowdsourced. This figure comes from builder and parts-supplier pages, not from the engine's maker or an ECU manufacturer. Treat it as a lead, then check your specific sensors and manuals.

How the planner reads the trigger text

Crank sensor type
Hall
Cam sensor type
Hall
Cam position sensors
1
Variable cams
0

Wire-in ECUs that cover it: 9 as they come, 20 more with add-on modules. The count is the planner's, worked out from the pin tables.

Fits as it is 9
Fits with add-ons 20

Plan a build around the LSA (Gen4 6.2 alum, S/C)

Pairing the engine with a gearbox? BoxSelector has the ratios for the boxes that bolt up to it, and works out road speed and tyre size before the money goes: gearbox ratios.

Sources

  1. GM Chevrolet Performance: LS3 EFI Crate Engines Specifications, part 19419889, rev 15AP20 Engine maker
  2. GM Chevrolet Performance: LS3 crate engine, tech specs Engine maker
  3. GM Chevrolet Performance: LS7 EFI Crate Engines Specifications, part 19329268, rev 16OC14 Engine maker
  4. GM Chevrolet Performance: LS Series Crate Engine Control System, part 19171935, rev 19MY16 Engine maker
  5. GM Service Parts Operation: LS Ignition Controller 19355418 sheet Engine maker
  6. Wikipedia: General Motors LS-based small-block engine Wikipedia · Generation III (1997–2007) infobox, Generation III infobox, Design, Generation IV (2005–2020), Generation III (1997–2007), LS6, LQ9, Generation IV (2005–2020) infobox, Generation IV infobox, L76, L92 / L9H / L94, LY6, L96, LSA, Gen IV (LSA)
  7. Haltech: LS1 engine Haltech (ECU maker) · Injection, Ignition Coils
  8. Haltech: LS1 trigger Haltech (ECU maker) · Crank Trigger, Cam Trigger
  9. Haltech: LS2 LS3 gen 4 engine Haltech (ECU maker) · Injection, Ignition Coils, Crank Sensor (pin C 12V+), Cam Sensor, General Information
  10. Holley: TECHLIBRARY199R10555REV17 Holley (ECU maker) · p12, section 8.1 (standing ruling)

Always verify against the manufacturer's manual and your tuner before wiring.