LS1 (Gen 3) Engine
Information on the General Motors LS1 Gen III engine
Holden Commodore LS1 engine
Number of Cylinders | 8 |
Capacity | 5665cc (346ci) |
Firing Order | 1,8,7,2,6,5,4,3 |
Cylinder Orientation | (1357 RHS) |
Injection System
All LS1 engines operate under sequential injection with an injector located in the inlet manifold spraying directly onto the intake valve. Injectors are High Impedance. The fuel system is of a non-returning type run at a fixed fuel pressure.
Early models used 230cc injectors
Later models used 250cc injectors.
Sensor Information
Trigger System
The LS1 engine has a trigger system mounted on the crankshaft that has a 24x tooth pattern. The camshaft has a half-moon style tooth.
LS1 Crankshaft showing crank trigger system
LS1 camshaft sprocket showing half moon trigger system
Crank Sensor
The crank sensor is unique in that it is a reluctor sensor that has internal signal conditioning to convert the signal into a digital Hall Effect style. As such the ECU should be configured as a Hall Effect crank sensor. It uses the Falling edge of the signal which has a common timed edge. The Rising edge of the signal has unique timed signals that cannot be used by the Haltech Elite ECU range. It is located above the starter motor towards the rear of the engine block. Gen 3 sensors are black, Gen 4 sensors are grey and cannot be used with a gen 3 crankshaft trigger pattern.
| Crank Sensor Pin | Haltech Connection |
| A | Trigger + (Yellow) |
| B | Signal Ground (Blue) |
| C | 12V+ (Red) |
Cam Sensor
The LS1 Cam Sensor is of a normal Hall Effect type. For Gen 3 engines it is located at the back of the engine at the top of the V.
| Cam Sensor Pin | Haltech Connection |
| A | Trigger + (Yellow) |
| B | Signal Ground (Blue) |
| C | 12V+ (Red) |
Trigger Configuration
Ignition System
LS1 engines operate as Direct Fire with a coil per spark plug mounted on the rocker covers of the engine. These coils have internal igniters and can be wired directly to the Haltech ECU.
Ground both pins A and B to the Cylinder Head
Set to Constant Charge with Falling edge. Using Rising edge will damage the coils.
Dwell Time
Drive By Wire (DBW) Throttle System (for models so equipped)
The LS1 uses a single Drive By Wire throttle body. This can only be controlled by an Elite 2500 or 1500 model ECU.
The VZ Commodore LS1 does not have the DBW Throttle and Pedal wired to the ECU. They are instead wired to what is called a TAC Module which is in turn controlled by the ECU.
VZ Commodore DBW throttle body
| Pin | Description | Haltech Connection |
| A | Motor Control 1 | DBW 1 (Brown/Black) |
| B | Low Reference | Signal Ground (Black/White) |
| C | Motor Control 2 | DBW2 (Brown/Red) |
| D | Low Reference | Signal Ground (Black/White) |
| E | 5V | 5V+ (Orange) |
| F | TPS 2 Signal | AVI-3 (Orange/Red) |
G | TPS 1 Signal | AVI-2 (Orange/Black) |
H | 5V | 5V+ (Orange) |
DBW Accelerator Pedal Position
VZ Commodore Pedal
Throttle Position Sensor (Cable Throttle Models)
| Pin | Description |
| A | 5V+ |
| B | Signal Ground |
| C | Signal |
MAP Sensor
The LS1 engine comes with a MAP sensor located on the inlet manifold.
| Pin | Description |
| A | Signal Ground |
| B | Signal |
| C | 5V+ |
Calibration: Use "MAP - GM 1 Bar.cal"
Idle Control
Models that have a DBW Throttle use the throttle for Idle Control. Models with a Cable throttle body use a Stepper Motor idle control system.
The stepper motor idle control is only supported on the Elite 1000 and higher ECU models.
It is not supported on Elite 550, 750, or 950 ECU models.
| Pin | Haltech Connection |
| A | Stepper 4 |
| B | Stepper 3 |
| C | Stepper 2 |
| D | Stepper 1 |
Drive Type: Both
Steps:240
Speed:75
Coolant Temperature
Located on the LHS cylinder head near cylinder 2 exhaust pipe.
Uses Delphi connector that requires the wire to be fed through the connector first, the pin crimped, and then pull back to lock the pin in place.
Wiring is not polarity sensitive
Calibration: Use "Temperature - Holden VP V8 Coolant Sensor.cal"
Created for Haltech ECUs using a 1k pullup to 5V
Air Temperature
Located on airbox
Uses Delphi connector that requires the wire to be fed through the connector first, the pin crimped, and then pull back to lock the pin in place.
Wiring is not polarity sensitive.
Calibration: Use "Temperature - Holden VP V8 Air Sensor.cal"
Created for Haltech ECUs using a 1k pullup to 5V
Oil Pressure Sensor
The LS1 comes with a 130psi rated Oil Pressure Sensor.
Pin | Description | Haltech Connection |
A | Signal Ground | Signal Ground (Black/White) |
B | 5V+ | 5V+ (Orange) |
C | Signal | Spare AVI |
O2 Sensor
The LS1 comes with 4-wire narrowband O2 sensor. It is strongly recommended to replace the front O2 sensors with a wideband O2 kit such as the Haltech WB2.
| O2 Sensor Wire Colours | Haltech Connection |
| Black (Signal) | AVI 1 or AVI 6 |
Grey | Signal Ground (Black/White) |
White | 12V+ Switched |
White | Chassis Ground (not Signal Ground) |
The heater wires are not polarity dependent. The heater ground can be pulsed with an ECU output. Use an Injector, Stepper, or DPO for this. DO NOT USE an Ignition output.
Knock Sensor
The LS1 has 2x older design resonant style knock sensors located in the valley of the engine.
They can be used however they are prone to failure. They are also oriented to read front to back, not bank to bank. For better results switching to the more modern non-resonant "donut" style sensors and locating them on the outside of the block allows better bank control of knock.
MAF Sensor
Commonly deleted when a Haltech ECU is installed, however it can be used if preferred.
There are 3-wire and 5-wire MAFs available on LS1 engines. The 5-wire type incorporates an Air Temperature Sensor
3-pin type
| MAF Connection | Haltech Connection |
| A - Yellow (Signal) | Any spare AVI |
| B - Black/White (Ground) | Sensor Ground (Black/White) |
| C - Pink (12V+) | 12V+ Switched (Grey/Red) |
5-pin type
| MAF Connection | Haltech Connection |
| A - Purple (Air Temp Signal Ground) | Sensor Ground (Black/White) |
| B - Tan (Air Temp Signal) | Any Spare AVI (AVI 7 Typical) |
| C - Black/White (MAF Ground) | Sensor Ground (Black/White) |
D - Pink (12V+) | 12V+ Switched (Grey/Red) |
E - Yellow (MAF Signal) | Any spare AVI |
OEM ECU Information
Automatic Transmission
4L80E
The 4L80E transmission requires ECU control of shifting and lock up converter.
Unique Information
Common Issues
Trigger Errors
With a cam swap it is common to have issues with the cam sensor signal occurring too close to a crank sensor edge. If the cam sensor edge swaps from before to after the crank sensor edge, or vice versa, an engine position error will occur. Monitoring the Home Percentage of Valid Travel channel shows how close the edges are to each other. If it is too close to either 0 or 100% then this can occur with a running engine.
Possible solutions are:
1. Try a different cam edge. This requires a TDC Offset change of 360, so either adding or subtracting this amount while keeping the value between 0 to 720.
2. Try adding filtering to the Home. Increasing to 2 or 3 can delay the Falling edge enough to keep it away from the crank sensor edge. The higher the rpm, the high the Home % channel will report.
Incorrect Trigger Pattern
Mixing of Gen 3 and 4 parts can be common when a custom engine is assembled. Most combinations will work however there is one combination that cannot work.
Crank Trigger Pattern | Cam Trigger Pattern | Will it Work | Configuration Trigger Type |
24x Gen 3 | 1x Gen 3 | Yes | General Motors - LSx Gen III (24x + 1x) |
24x Gen 3 | 4x Gen 4 | No | --- |
60-2 (58x) Gen 4 | 1x Gen 3 | Yes | Generic Missing Tooth Single Tooth Home Trigger Signal Location = On Crank Number of Teeth = 60 Number of Missing Teeth = 2 |
60-2 (58x) Gen 4 | 4x Gen 4 | Yes | General Motors - LSx Gen IV (58x + 4x) |
If the engine is yet to be built and a decision is to be made as to which trigger system is best, the Gen 4 trigger is a better option that allows a wider range of cam position movement before trigger errors are an issue. The missing tooth crank trigger also provides a higher level of redundancy as well as faster sync and engine startup.
No Crank Trigger Input
It is possible to have an incorrect crank position sensor installed. The grey sensor from the Gen 4 motor cannot be used with a Gen 3 crank trigger wheel. The trigger pattern and sensor type must both match.
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