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Electronic |
Electronics Probably
the challenging part of the VE swap |
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Engine Electronic Control Unit (ECU) This is the Original ECU (below) that came with the Primera: Nissan Primera P11 1997 SR20DE ECU (no solenoid control) Bosch 0 261 203 857 - 23710 3J501 - 3J501-85800 CHIPs A19-257027 & A19-257045 Crystal - 7998.0 6HT AMQ-26
This is the Original ECU (bel;ow) that came with the imported SR20VE motor (engine). The Electronic Control Unit for the engine (ECU) This is a source of major headache for the install. I asked for n ECU with the motor, the engines don't always come that way. The original ECU's have the solenoid cam switching controls built in to them, they also have a 7,200 rev limiter and and 112mph speed limiter. The cam switching points are 5200 (inlet) & 5700 (exhaust) a staggered arrangement best suited to the CVT station-wagon. This one is made by the UNISIA JECS corporation of Japan probab;y dating from around 1999. Nissan Primera P11 circa 1999 SR20VE ECU (solenoid control and CVT restrictions) Unisia JECS (circa 1999) 23710 5J000 - A18-G60 C85 CHIP A12-212750 718B100 CB1E135J Crystal - 15996.0 7ET AMQ-28
Another example of an SR20VE ECU, probably older (circa 1997) note the lower level of component integration Unisia JECS (circa 1997) CHIP A12-212600 M37790STJ 522A100
I successfully ran the VE ecu for some weeks, the engine was very smooth and responsive however the limiters really annoyed me. The cut-offs at both revs and speed are very aggressive, the engine just blows nil power -- quite disconcerting. I contacted a USA VE dealer for an uncommon solution, I bought an SR16VE ECU, thats the 1600cc version of the engine, that ECU has a very much higher RPM limit due to the fact it carries lower movement inertia and was fitted to a manual gearbox. This ECU then had a higher rev limit but still a 112mph speed limiter, I fitted a proprietary GREDDY part to remove the speed limiter, I think that it "fools" the ECU into believing that the car is still doing 111mph when you infact surpass that speed, an in-line device fitted on the road speed sender.UK built Primeras come with a German made BOSCH ECU, quite different in circuit design to the Japanese even though the loom interface connector is identical. That is why I went for the Japanese VE ecu, I did not think that my BOSCH ecu would be servicable to JWT. WIRING LOOM & CONNECTORS The installation demands that you remove both harness from each engine. The DE harness has to go on to the VE engine, there are a number of reasons for this: 1)The VE harness is complicated by CVT controls that have no purpose and could cause complication 2) The DE chassis has it's own instrument binnacle relationship and related sensor feeds, namely DE temp sendor, DE O2 sender, DE gearbox speed sender
Getting the harnesses off is a pain, very difficult when the motor is in the bay, the DE is a "stretch" onto the VE engine especially across the front for alternator but luckliy many of the supplementary harness lie un-disturbed (ABS, Lighting etc). Its only the engine control harness that you swap.The Japanese ECU relies on inputs from various engine parameters. You cannot use the VE wiring loom because of the extra CVT loom confusion (3 more unidentifiable plugs and 50 wires). You have to remove both DE & VE looms, compare the pinouts on the connector and the termination destinations. Then fit the DE loom to the VE engine. The vast majority of engine parameters are identical; eg knock sensor cooling fans, throttle position, starter, generator etc BUT there are some differences: 1) The Distributor - The Japanese usually more recent engine (mine is a 1999 VE going into a 1997 Primera) have a better distributor (more electronic less mechanical) The wiring is different. I fitted the VE distributor after trialling different wire splice combinations! 2) The water Thermometer - This feature is twinned with your cockpit instrument panel, the meter in the dash is tuned to the sensor output. I moved my DE temp sender across to the VE block to get meaningful readings 3) The Mass AirFlow Sensor (MAF) - The VE ECU is twinned with the VE MAF, you don't usually get the VE MAF when you buy the motor. Altough you can use the DE MAF ont he VE its very sub-optimal. You have to source a VE MAF from the USA or somewhere! 4) The Cruise Control plug - there is no cruise control on my DE, therefor nothing to plug into the VE throttle body socket but it doesn't seem to matter. Wiring Diagrams: You need to be surre that you've got the correct engine control pin-outs in your swap, to be sure that you've got it right you need to be organised and adopt a degree of sleuth-like deduction. I used a combination of wiring diagrams, Excel spreadsheets and "side by side" harness circuit checking, all very laborious especially when you expressly CANNOT rely upon wire colours! I attach my lists and diagrams but you must make your own calculations for satisfaction in your own install: You'll need to save these images to your computer to take a closer look!
Here is the source of the VE data, an ECU circuit diagram in Japanese version, translated by me.
You will see some pinouts highlighted in red on the spreadsheets, these were problem clashes, the worst being PIN 106 which needs to be swapped around otherwise your car will have the fuel pump switched on and off instead of the cam solenoid!! I stripped out the entirety of the solenoid wires from the VE loom and wove them into the DE loom, keeping the wires and connector receptacle intact. Solenoid Triggers, Rev limits and Speed Limits VE ECU in position with wires The VE ECU comes with pre-set triggers, a 7,200 rev limit and 112mph speed limit. I developed a good "spade and receptacle" adaptor for the two solenoids, a smart way to drop the exhaust solenoid trigger value is to wire it to the same trigger as the inlet, see the red coloured 2to1 harness. The modern way to trigger the solenoids is using a Greddy Switching module (MSS) (see detail further below), in this shot I've abandoned the VE ECU entirely for Switching. Instead of the ECU you'll notice how the two solenoid wires are now connected to a yellow and green trigger wire from the MSS. You will also see the Greddy Speed limit controller wired into the speed signal wire (modifying its output).
Engine Bay Solenoids Here you can see the two solenoid connectors, brown cap with orange and black signal wire is nearest the cam cover and the inlet bank, the green cap with the pale green and red stripe signal wire is the exhaust bank. The connectors are not interchangeable. Measuring the signals and switching points in real time is quite difficult. The signal wires give electrical ground to the solenoids, the other wires provide a constant 12VDC when the engine is running. You must ensure that a good current pull is possible through this circuit or you could get the cams faltering on activation.
Greddy Multi-Switching System (MSS) http://www.greddy.com/prod_multi_switching_sys.htm This is a universal controller that can be turned to any purpose, its both sophisticated and durable for the cam switching exercise. I did get a translation of the Japanese user guide but it's still incomprehensible. This is my recommended configuration, and I learnt the hard way how to set htis up.
White wire - Analog Voltage signal from the Throttle Position Sensor (TPS) solder piggyback to the ECU pin 20 Grey wire - Ground (-12VDC) Brown wire - RPM feed from the ECU to the Instrument Cluster solder piggyback to ECU pin 2 Blue wire - Speed Sensor (MPH/KMH) from the gearbox sensor solder piggyback to ECU pin 32 Red wire - +12VDC ignition feed (on when engine is on) Orange wire - +12VDC accessory feed (on when Ignition key is in barrel) Black wire - -12VDC Ground Yellow wire - Inlet Solenoid, Orange Black wire ECU pin 102 Green wire - Exhaust Solenoid, Green Red wire ECU pin 106 The MSS comes supplied with a twin black fuse unit (popularly mis-understood as a relay) You do not need to use the relay but I guess good installs would have one to protect your soleniods and MSS. I learnt that hard way that the MSS gives ground (not +ve supply) when its switches. In frustration one day I experimented with an un-fused 12 VDC feed and burnt out the power transistor inside the MSS unit (bang and smoke! - not recommended) However the unit did prove repairable witht he correct part!
Setting-up the MSS This controller is sophisticated, if you've followed my wiring recommendations above then you can do all kinds of tricks around the three sensor parameters. You've got an RPM feed, a throttle feed and a speed feed, the MSS can switch two circuits separately and independently using any one or combination of the the sendor feeds. In addition you can observe the real-time sensor feeds and watch the trigger points happen on the MSS lcd screen! For this application the RPM feeds are most important and the setup will show that feed however if you add another sensor feed then that will become a "conditonal'" "and" operator (If your RPM settings say switch-on but your second sensor setting says NO! then the cams won't switch) I recommend that you keep it simple especially when you factor in the ability of the unit to switch in and out at different values whether a rising or falling! You can see that I've mounted the unit in a cockpit view position by my right knee (RH drive), it was convenient for electrical power feeds and the wires reach across to the ECU at a stretch. I can easily make adjustments from the drivers seat and glance at the real-time function whilst driving.
Basic Appearance Screens - You can move the gas pedal up and down and watch the TPS voltage rise and fall, note the low and high settings for interest only
There's a warning bell feature for every sensor, here I've set it at 4.2V TPS, 150MPH and 7,450rpm - really the RPM is the only useful one here although I guess it would be nice to know if I exceed 150MPH!
The mode button allows you to watch each sensor in real-time when the engine is running, typically when parked you could expect these: 0.43V TPS, 0.00 MPH and 830RPM, interestingly the MSS will give you more honest accurate and lower RPMs than your tachometer.
You can set the brightness of the LCD and the loudness of the warning beep. Pressing the mode screen will put you into sensor configuration screens.The MSS is designed for many applications so you will see menu choices for all kinds of parameters irrelevant to this application, Boost, temp & pressure - just ignore these setup screens:
I chose to use two parameters for my configuration TPS and RPM, that's two different channels with two dependencies at both a rising and falling value ie. I want the solenoid to kick ON once my pedal position rises above aTPS value AND once a certain RPM is reached. Setting the values is as easy as spinning the rotational dial for your required value and saving the value with a button press. Channel 1 inlet cam setting: Solenoid is ON once TPS > 3.00V AND RPM rises past 5400, switching off as the RPM drops back past 5400RPM AND 3.00V on the way down.
Channel 2 Exhaust cam setting: Solenoid is ON once TPS > 3.00V AND RPM rises past 5600, switching off as the RPM drops back past 5600RPM AND 3.00V on the way down.
Thats the setup done, you can now run it and change the settings according to your driving needs or at the rolling road for performance.
The Speed Cut, there's a well proven device to remove the 112mph limit http://www.greddy.com/prod_cut_controller.htm
Wiring instructions for the Profec Speed Cut device Red wire - +12VDC positive supply or ECU PIN 47 Black Wire - -12VDC or Earth - ECU PIN 48 Blue wire - Speed Sensor - signal from gearbox, spliced into wire to ECU PIN 32 (in this case mated with MSS blue wire as well) Brown wire - Modified output speed signal goes to ECU PIN 32 Yellow wire - unused (probably an additonal speed triggered feature)
fHere it is finished! An SR16VE ECU running an 8,500 rev limit, no Speed limit and infinitely variable user determined cam-switching. |
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www.sr20ve.co.uk - documenting a UK install and tune-up |
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A
resource for Nissan fans the world over
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