VVC Information

2010-02-07T20:12:08Z

Benjam: added s1 vvc swap info

The Elise S1 143bhp EU2 VVC is controlled by the MEMS 2J ECU common with the early VVC MGFs

The Elise S2 156bhp EU3 VVC is controlled by the Lotus K4 ECU (which looks the same as the MEMS 3 but is *NOT*).

==EU2 & EU3 Differences==

The mechanicals which are different from the EU3 to EU2 engine:

1. 52mm TB as standard (EU2 48mm)

2. Wasted spark coil packs on top of the plugs (EU2 under induction)

3. KTM plate oil/water cooler under the induction (EU2 none)

4. Dark blue 192cc/min injectors (EU2 cream 218cc/min)

5. TF160 pistons with marginally higher compression and expanded ring belt to strengthen ring lands, indentifiable by '160' engraved on the crown

6. Machining of the head around the inlet and exhaust valves (triple-angle valve seats) both in the valve throats and combustion chamber to improve low lift flow

7. VVC control connectors are differnt colours and have different keyways

8. IACV MDQ100170 is PWM (EU2 is Stepper)

9. Cam Position Sensor NSC000010 has a longer pickup (EU2 is NSC100380)

==VVC Failure Modes==
ECT Sensor Error Limits to 6K RPM

MAP Sensor Error limits to 6K RPM

VVC Solenoid low resistance (should be 6.6 to 8.8 Ohms) Limits to 5.5K RPM

Cam Position Sensor Limits to 5.5K RPM (The VVC CPS is NSC000010 variable reluctance, different to the standard K16 Hall effect)

Excellent write up on the S1 EU2 VVC MEMS 2J logic and failure modes here * http://www.mgfcar.de/library/ENGINE_MANAGEMENT_SYSTEM_VVC_MEMS_2J.htm

Excellent write up on the S2 EU3 VVC MEMS 3 logic (which the K4 is based on) and failure modes here *
http://www.mgfcar.de/library/ENGINE_MANAGEMENT_SYSTEM_%20MPi_VVC_MEMS_3.htm

Note: Connecting the battery on wrong polarity can blow the K4 ECU VVC control circut, as can running with a low resistance solenoid. Lotus issued a service note on this.

==Lotus S2 K4 ECU VVC Connections==
{|
| K4 Pin || Wire || Function || Connector
|-
| 06 || Blue || VVC Oil Temp Earth || BLACK
|-
| 10 || Green Orange || VVC Oil Temp Signal || BLACK
|-
| 12 || Black Yellow || VVC Decriment || BLUE
|-
| 49 || Brown Black || VVC Increment || BROWN
|-
|}

The S2 Connector order is LEFT < Blue - Brown - Black > RIGHT VVC Actuator

The S1 connector order is LEFT < Blue - Black - Brown > RIGHT VVC Actuator

[img]http://gallery.seloc.org/albums/userpics/24232/S2_VVC_Engine_Sensors.JPG[/img]

==Lotus S2 K4 ECU VVC DTC Codes==
The S2 ECU is ODB2 compliant (ISO9141/KWP2000) so can be read by most scantools. Of course the S1 MEMS isn't OBD2 so no idea what that spits out ...

{|
| Code || Description ||
|-
| P1336 || S2 Crankshaft Position System Variation Not Learned ||
|-
| P1480 || S2 Exhaust flap relay open ||
|-
| P1481 || S2 Exhaust flap short circuit ||
|-
| P1490 || S2 VVC brown increment solenoid open circuit (Black Yellow) ||
|-
| P1491 || S2 VVC brown increment solenoid short circuit (Black Yellow) ||
|-
| P1492 || S2 VVC blue decrement solenoid open circuit (Black Brown) ||
|-
| P1493 || S2 VVC blue decrement solenoid Short circuit (Black Brown) ||
|-
| P1494 || S2 VVC black oil temp sensor LOW open circuit (Green Orange + Blue) ||
|-
| P1495 || S2 VVC black oil temp sensor HIGH short circuit (Green Orange + Blue) ||
|-
|}

==VVC and Emerald ECU==
Emerald K3 ECU needs to be firmware revision 1.13 to filter out Cam Position Sensor noise that can cause VVC cam control issues at high RPM.

==External Resources==
VVC Sensors * http://homepage.swissonline.ch/TomsSeven/Navigation2/Map.htm

VVC Sensors * http://www.mgfcar.de/sensor/index.htm

VVC Mechanism Assembly * http://www.davebence.co.uk/mods_10.htm

VVC Timing * http://forums.mg-rover.org/showthread.php?p=1940938

[[Category:Engine]]
[[Category:Lotus Elise]]
[[Category:S1]]
[[Category:S2]]

==Fitting an EU2 VVC Engine to a non-VVC S1 Elise==
Lotus didnt make any changes to the car's wiring loom between their standard 120bhp S1 and the 143bhp VVC powered 111S. This means that you can easily fit an EU2 VVC K-Series engine (eg. from an MGF) and run it using the Rover MEMS J2 ECU. All you'll need is a donor VVC engine, engine loom and a matching Lucas 5AS module (sits behind the Stack dashboard) to make the swap.

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VVC Information