Lockhart Phillips/70-30 Racing
'07 Aprilia SXV 5.5
- Rebuilt Motor
- New Starter
- New Tires
- Hand guards
- New brakes pads
- New relay
- New Battery
'05 Aprilia Mille R
450 Husky SMR
If you like examining the schematics, then you'll love reading this...
I'm trying to fully understand the ramifications of stopping the engine using the Ignition Switch vs. Run/Stop Switch vs. a stall. So...
The Ignition Switch (8) is a 3PST (3-pole, single throw) switch separated from the wiring harness by the ignition switch connector (1). Turning the ignition switch to the ON position connects the following three circuits:
- Grounds the Run/Stop & Start controls - shorting the Yellow (G) and Green/Brown (V/N) wires, through the ignition switch connector (1), causes the Blue (B) chassis ground wire to be connected to the Light Blue/Gray (Az/Gr) wire which supplies ground to the Run/Stop & Start controls (10), a.k.a. RH Dimmer Switch, via another connector (1).
- Supplies power to the Instrument Panel (4), Parking Light (46), Flasher, a.k.a. Repeater, (5), Horn & Scroll switches on the Left Handlebar Controls, a.k.a., LH Dimmer Switch (6), Tail Light (14), Number Plate Light (15), and through the Resistor (50) to the Fuel Level Sensor (20) via a connector (1) and the Fuel Level (CARBURANTE) terminal #9 on the Instrument Panel (4). This power originates from the Battery (26) + terminal Red (R) wire which connects to Auxiliary Fuse (19) #2. A Red/Brown (R/M) wire connects the fuse to both the Instrument Panel (4) Battery Power input terminal #14 and the ignition switch connector (1) leading to the Ignition Switch via a Green (V) wire. Turning ON the ignition switch connects the Green (V) wire to the Orange (Ar) wire which passes through the ignition switch connector (1) to a Green/Orange (V/Ar) wire which supplies power to all of the above.
- Supplies power to the Light Relay (9) coil, Speed Sensor (3), and ECU (44) terminal #8 (appears to be ECU power connection). This power originates from the battery (26) + terminal Red (R) wire which connects to Auxiliary Fuse (19) #1. A Red/Gray (R/Gr) wire connects the fuse to both the ECR Relay (27) coil and the ignition switch connector (1) which connects to the Ignition Switch (8) via a White/Red (Bi/R) wire. Turning ON the ignition switch connects the White/Red (Bi/R) wire to the Red (R) wire which passes through the ignition switch connector (1) to a Yellow/Pink (G/Ro) wire supplying power to all of the above.
Energizing the ECR Relay (main power):
The ECR Relay energizes under control of the ECU and powers most all systems. The following circuit energizes the ECR Relay: Current flows from the battery (26) + terminal to the auxiliary fuse #1 (19), then via the Red/Gray (R/Gr) wire to the ECR Relay (27) coil. The other side of the ECR Relay coil is the Blue/Black (B/N) wire which connects to the ECU (44) terminal #26. Thus, when the ECU connects terminal #26 to ground, the ECR Relay is energized by current flowing through this circuit. From experience, the ECR Relay is energized by the ECU a few moments after the ignition switch is turned to ON.
ECR Relay Power Distribution:
Power from the battery (26) + terminal feeds auxiliary fuse #4 (19), then via the Red/Green (R/V) wire to the ECR Relay (27) contacts. When energized by the ECU (see above), power flows across the contacts to the Red/Blue (R/B) wire which connects power to all of the following:
- ECU (4) terminal 9. As the ECU activates the ECR Relay, it is likely that this terminal is simply feedback that the ECR Relay is energized.
- Auxiliary Fuse (19) #5 - Supplies power via Orange/Red (Ar/R) wire to Ignition Coils 1 and 2 (35/33); and via Red/Yellow (R/G) wire through a connector (1) to Injectors 1 and 2 (41/40). Actual activation of the ignition coils/injectors occurs when the ECU shorts the opposite lead to ground.
- Auxiliary Fuse (19) #6 - Supplies power via Red/White (R/Bi) wire through a connector (1) to the Fan (18). The fan activates when the ECU shorts the opposite lead to ground.
- Auxiliary Fuse (19) #7 - Supplies power via Violet/White (Vi/Bi) wire through a connector (1) to Fuel Pump (21) + terminal. The fuel pump operates when the ECU shorts the opposite terminal to ground.
- Starter Relay (24) coil. The starter relay coil is energized when the ignition switch is on, AND, the Run/Stop switch is set to Run, AND, the Start switch is depressed.
Run/Stop & Start Controls:
The Run/Stop & Start controls (10), a.k.a. RH Dimmer Switch consists of two separate switch controls: a locking Run/Stop switch, and a momentary Start switch. None of these controls function unless the Ignition Switch (8) is turned to ON which provides a ground connection to the Run/Stop switch (see Ignition Switch above) via the Red/Green (R/V) wire.
- Locking Run/Stop Switch - In the Stop position the Red/Green (R/V) wire is shorted to the Yellow/Light Blue (G/Az) wire which leads to the wiring harness connector (1). A Gray/Black (Gr/N) wire then leads to the ECU (44) terminal #4. Presumably, a ground signal here notifies the ECU when the switch is in the Stop position. In the Run position the Red/Green (R/V) wire is shorted instead to the Red/Black (R/N) wire which provides a ground circuit to the Start Switch.
- Momentary Start Switch - Depressing the Start Switch shorts the Red/Black (R/N) wire to the Yellow/Red (G/R) wire leading to the wiring harness connector (1). A Blue/Black (B/N) wire in the wiring harness then leads to the Starter Relay (24) coil. A ground signal is thus transmitted to the starter relay coil when the ignition switch is ON, the Start/Run switch is set to Run, and the Start switch is depressed.
The Starter Relay (24) is energized when it is supplied power by the ECR Relay (27) (see ECR Relay Power Distribution above), AND, is provided with a ground signal from the Start Switch (see Run/Stop & Start Controls above). A Safety Diode (22) installed across the starter relay coil shunts potentially damaging inductive reverse-currents.
The Starter Motor (25) is supplied power when the Starter Relay (24) is energized. Power is supplied directly from the Battery (26) + terminal via Red (R) wire to the Starter Relay (24) contacts. When energized, power flows through the contacts via Red (R) wire to the Starter Motor (25) which is directly connected to chassis ground.
Now, for the FUN part...
Stopping the Engine: Ignition Switch or Run/Stop Switch?
From the discussion above it can be seen that the Run/Stop switch does the following:
- Provides a signal to the ECU when in the Stop position
- Provides a ground path to the Start switch when in the Run position
Only the first point is relevant to stopping the engine because the Start switch circuit does not come into play.
Circuits affected: The Run/Stop switch ONLY effects a signal to the ECU to stop the engine. This leaves the ECU entirely in control.
The more lengthy discussion of the Ignition Switch reveals it controls power for nearly every system:
- Run/Stop & Start Controls
- Instrument Panel, Parking Light, Flasher, Horn and Scroll buttons
- Light Relay, Speed Sensor, ECU terminal #8
Of interest in this list is that the Ignition Switch disables the Run/Stop control. Therefore, it is evident that stopping the engine using the Ignition Switch does AT LEAST the same action as using the Run/Stop switch, if not more.
We are not interested in the lights and horn, and can probably (somewhat safely) assume that the instrument panel (and Scroll switch) don't have any effect on stopping the engine. The speed sensor could leave a bit of doubt open, however.
Of prime interest, though, is that the Ignition Switch seems to supply power to the ECU via terminal #8. Upon examining the schematics, it seems this is the only terminal that supplies power to the ECU other than terminal #9. But terminal #9 is supplied through the ECR Relay which is controlled by the ECU! So, it's obvious that terminal #9 is not a power connection because then the ECU would also turn itself off in addition to the ECR Relay!
Therefore (albeit inconclusively), we can feel somewhat comfortable in concluding that the Ignition Switch controls ECU power; and, that stopping the engine with the Ignition Switch results in total shutdown yielding a "free-wheeling" engine without ECU control.
Circuits affected: If we conclude that using the Ignition Switch cuts power to the ECU, then it's pointless to worry about the Stop signal from the Run/Stop switch or the Speed Sensor signal. Simply, all engine control is cut-off because the ECU loses power.
CONCLUSION: It's impossible to determine from the schematic that using the Ignition Switch to stop the engine is harmful; however, it appears nearly obviously that using the Run/Stop switch simply signals the ECU to stop, while using the Ignition Switch likely completely cuts power to the ECU. If harm is, in fact, possible, then leaving the ECU powered, in control of the engine, and signaling a stop definitely seems preferable to simply cutting power to the ECU abruptly. Therefore, using the Run/Stop switch appears to be prudent. Bolstering this with the fact that undesirable mechanical noises emanate when using the Ignition Switch, there appears to be more than just prudence in justifying use of the Run/Stop Switch as an exclusive engine stopping procedure. Lacking further technical knowledge of the ECU and/or origins of the mechanical noises, it would make sense to specify use of the Run/Stop switch as an exclusive mandate. Is there any evidence that a "controlled" stop includes continuing spark/fuel or some other sort of "ramp-down" control by the ECU? Also, is there any good explanation why a sudden loss of spark/fuel would cause whatever sort of backlash or damage is claimed? My car always stops safely....??
What about stalling the bike (or cold-start stalls)?
I simply have no idea on this one... But, it's not exactly preventable...
The positive: Since the ECU remains powered during a stall, the ECU should be able to correctly handle the condition without invoking damage or harm.
The negative: The noises emanating from a stall (which are similar, by possibly not identical, to stopping the bike using the ignition switch) aren't positive sounding. Repeated stalls cause over-use of the starter and drain the battery.
CONCLUSION: Inconclusive. But, I still don't like it!
I have talk about with Aprilia Germany and Racing Team. They all said only stop over kill switch. I have read your schematic. Thats all right. But Aprilia said that the problems on starter and freewheel only comes from this Phenomenon.
Probably very amusingly this problem remains, why, why and how...