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LPG and CNG. Sequent Plug & Drive. Sequent Plug & Drive is the new system for LPG/CNG conversion developped by BRC. Designed on the basis of the previous Sequent systems but characterised by a totally new approach of gas flow management.
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Sequent Plug & Drive • Sequent Plug & Drive is the new system for LPG/CNG conversion developped by BRC. • Designed on the basis of the previous Sequent systems but characterised by a totally new approach of gas flow management. • Main innovation is in the software for engine management. Thanks to its new algorithms, it allows an optimised feeding of gas fuel, in a simply and intuitive way. • Some of more advanced functions have been integrated and others have been added in order to simplify the calibration procedure.
SEQUENT PLUG & DRIVE – LPG KIT • Into the kit • LPG Solenoid valve ET98 • Genius MB/Max reducer (water temperature sensor 2 poles) • Fuel Rail with BRC injectors and PTS sensor (brown connector) • MAP Sensor with integrated connector (grey) • ECU • Harness • Change-over switch one-touch with buzzer • Gas filter FJ1 HE • Out of the kit • Harness for petrol injector cutting (dx, sx, etc.) • High pressure pipe (copper or flexible at choice)
SEQUENT PLUG & DRIVE – CNG KIT • Into the kit • VM A3/E solenoid valve • Zenith reducer (water temperature sensor 2 poles) • Fuel Rail with BRC injectors and PTS sensor (black connector) • MAP Sensor with integrated connector (grey) • ECU • Harness • Change-over switch one-touch with buzzer • Out of the kit • Harness for petrol injector cutting (dx, sx, etc.) • High pressure pipe (copper or flexible at choice) • Filling nozzle
HARNESS • To connect • Power • Ignition on • Optional • Connection to OBD plug depending on type of connection • Lambda oxygen sensor IN • “In case of need” • Lambda oxygen sensor OUT • External timing advancer(for CNG) • RPM signal
NEW GAS ECU • HARDWARE INNOVATION • Communication with new change-over switch and PC on same K line • Communication with petrol OBD on K line or dedicated CAN • Output for timing advancer external unit (for CNG) • SOFTWARE INNOVATION • Totally revised • Injection Control • Self-mapping • Leaning in Open Loop • Tip-in / Tip-out and Setup already activated New functions thanks to communication to OBD.
WHAT’S NEW: what you CAN’T see • Improvement in Fuel Control management • Improvement in RPM reading from petrol injector’s Ton: consequently, RPM signal is no more necessary • A new grafic for the interface sw has been created with same lay-out with all other Sequent systems
BASIC CONCEPTS Sequent PLUG & DRIVE system
INSTALLATION AND CALIBRATIONPROCEDURE FOR SEQUENT PLUG & DRIVE INSTALLATION SEQUENT PLUG & DRIVE IS VEHICLE OK? DRIVEABILITY À : REFINE TIP-IN, TIP-OUT, RETURN TO IDLE YES SELF MAPPING NO IS VEHICLE OK? (TIP-IN, TIP-OUT, RETURN TO IDLE) NO DRIVEABILITY: O.L. STRATEGY CHECK MECHANICAL INSTALLATION CHECK THE MAP AND VEHICLE PERFORMANCE NO IS VEHICLE OK? (OPEN LOOP condition) YES DELIVER THE CAR TO CUSTOMER YES
BRC injectors characteristics P1 T gas Step3 Step2 Step1 TonP reading Ton G calculation GAS flow calculation TonG TonP Gas flow Petrol flow MAP Injection: Calculation Petrol INJECTOR +12 V GAS EQUIPMENT CARACTERISATION +12 V Gas INJECTOR +12 V Orange Violet PETROL flow calculation GAS ECU Petrol ECU
SELF-MAPPING PROCEDURE SEQUENT PLUG & DRIVE START PROCEDURE SELECT TYPE EQUIPMENT (Step 1) SETUP EQUIPMENT AND TYPE OF INJECTORS (Step 2) SAVE FILE .FPD (Step 3) SELF-MAPPING (Step 4) SAVE FILE .FPD (Step 5) END OF PROCEDURE
SELF-MAPPING Start procedure … what’s 1st Correction Gas Map? Idle in petrol 3 accelerations Sequential Change-over Automatic from Petrol to Gas: 1st Correction Gas Map
1st Correction Gas Map Gas Injectorswitched Gas maperror 1° STEP 2° STEP 3° STEP 4° STEP
SELF-MAPPING Startprocedure End procedure 3° Correction Gas Map OK Idle in petrol CHECK DATA GAS MAP KO 3 accelerations Switch to gas: 2° Correction Gas Map Sequential Change-over Automatic from Petrol to Gas: 1° Correction Gas Map Switch to Petrol
CLOSE LOOP = Map refinement Correction at idle Correction at medium and high power OBD parametersbank 1 OBD parametersbank 2
CLOSED LOOP = Map refinement Gear correction Correction at idle “Easy Refinement” OBD parameters bank 2 OBD parameters bank 1
CLOSED LOOP = Map refinement CNG map parameter Ton at idle (in Gas operation)
Warning! • Important concepts Map Refinement – Close Loop • Idle control: taking into consideration MAP variation and checking Lambda sensor trend, check that, when switching from petrol to gas, TonP is still the same. When possible, connect EOBD tester to check self-adapting parameters • Gear control: check the map with TonP more than that at idle. I.e. 9-10 ms • If connection to EOBD plug is present, check the self-adapting parameters • Ton Min Gas = value of TonP at idle during gas mode • Map parameters: after map refinement, always check that numeric value of Q is negative (<0). If positive, some flow will be delivered by gas injectors even when petrol ECU is in cut-off (TonP=0)
BEFORE STARTING A DRIVEABILITY SETUP, BE SURE THAT GAS FLOW IS CORRECT CHECKING IT BY MAP REFINEMENT.
OPEN LOOP = Leaning in O.L. In the Closed Loop management, the petrol injection supplies the optimal fuel quantity in order to obtain a stoichiometric mixture (QPStoich.). The gas flow (QG) is calculated starting exactly from this petrol quantity. QPStoich. QG In the Open Loop management of the petrol injection, the stoichiometric conditions are usually abandoned in favour of a mixture richer in petrol (QBStoich.+ ENO.L.), of considerable percentages too (for instance 30%). QPStoich. + ENO.L. QG + ENO.L. For instance: QPStoich. + 30% QG + 30%
OPEN LOOP = Leaning in O.L. Working of the leaning in O.L. strategy The aim of the leaning in O.L. strategy is to limit the enrichment with which the petrol setup is calibrated for the working in Open Loop. QPStoich. + ENO.L. QG On the basis of the parameters acquired during the self-mapping, the strategy recalculates in a independent way the optimal petrol quantity(QPoptimal) needed to keep a rich calibration for the Open Loop condition, but limited compared to the original one. However, enrichment is always possible if needed. (EN LIMIT). = QPOptimal (Rich) QPStoich + EN LIMIT
OPEN LOOP = Leaning in O.L. When the leaning in O.L. strategy is enabled, system compares the Real Petrol Flow to the Optimal Limited one (recalculated by Plug&Drive system) to select on which one calculate the Gas flow. • When petrol ECU, working on gas, requires an higher enrichment compared to the Optimal Limited one, Sequent P&D will calculate gas flow starting from the Optimal Limited. > QPStoich. + ENO.L. QPOptimal (Rich) QG • If the Real Petrol Flow required by petrol ECU is lower than the Optimal Limited one, Sequent P&D will not make any cutting and gas flow will be calculated on the Real Petrol Flow < QPStoich. + ENO.L. QPOptimal (Rich) QG
OPEN LOOP = Leaning in O.L. • Description: • Vertical line is RPM indication. • BLUE line is the calculated amount of petrol without “Wall Wetting” strategy (Optimal Limited) • red points are values of lambda oxygen sensor, acquired during self-mapping • green points are actual fuel quantity required by petrol ECU. • If green points are above the blue line, strategy actually leans, down taking the fuel quantity to the blue points level, instead of level of green points • For RPM in which green points are below of the blue line, leaning is not done and gas quantity is the same required by petrol ECU, that of green point
EOBD Parameters • Connection to EOBD PLUG is not necessary for the good working of the vehicle in gas. • Some parameters read by EOBD plug are used by Sequent PLUG & DRIVE for further refinement of the fuel control. • In addition, these parameters make it easier the manual refinement of gas map, showing the value of the self-adapting parameters in the Map Refinement page. • EOBD parameters are also shown and should be recorded during the normal acquisition of gas paramenters in Data Monitoring page.
