The Lambda measurement system
AiM LCU-2 CAN has been designed in the first instance for the connection with AiM displays and data loggers. In the CAN-network with the MXL you can use 12 LCU’s at the same time. LCU-2 can also be used for engines that are not driven with fuel but with methanol, gas, diesel, etc. because the configuration software allows changing the 1 parameter.
LCU-2 is a control unit for the broadband lambda sensor of the BOSCH LSU 4.9. Its function is to control and supervise the correct operation of the lambda sensor and its heater and to output the calculated lambda data of the remaining oxygen contend of the exhaust gas digital over CAN.
The ideal air-fuel ratio (AFR) for Otto-engines, the so called stoichiometric ratio, is approx. 14.7. Meaning if one mixtures homogeneously 1 kg fuel with 14.7 kg air (approx. 11 m³), its combustion makes for the fewest emissions in its exhaust gas, because the chemical compound of the therein available hydrocarbon molecules (HC) with the adequate oxygen molecules of the air fits optimal. One speaks of a Lambda = 1-ratio. When the AFR = 14.7 one speaks about a thin ratio and if it’s smaller than 14.7 one says it’s a rich ratio. With Otto-engines one tries to reach an AFR value between 12.8 and 13.4, that is lambda = 0.88 and lambda = 0.92, at full load, not only because of the highest power at that point but also in order to save it from overheating.
LCU-2 the lambda-value in the exhaust gas between 0.65 and mere air.
In the communication over the CAN-bus (MXL Pista, MXL Pro, MyChron 4) it informs over the Lambda –value, AFR, temperature of the sensor and the self-diagnostics parameters. All measurement values are then indicated and recorded by the respectively Master.
CAN-Bus Technology
Special features LCU-2
- AiM CAN Bus Network (EXP)
- Lambda value
- AFR value
- Sampling rate up to 100 Hz
- external 12V input
- Lambda parameters adjustable
- Status LED
Connection example LCU-2
The inputs on the LCU-2
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| 1 |
Connection for LSU 4.9 Lambda sensor |
2 |
12V connection to the on-board net of the vehicle |
3 |
CAN connection to the Master |
Accessory for LCU-2
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| Data Hub |
Cable |
Temperature |
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