K12 Loss of Power/Rev Limiting/Holding Back
- Check the charging voltage throughout the rev range. Should be 14 volts approx, with load headlamps /rear screen heater on and/or off. Note that many vehicles built after 2004 have the regulator built into the ECU module and not the alternator.
- If out of normal voltage range than disconnect alternator and test drive a short distance to see if any improvement in rev range is obtained. If no improvement, reconnect alternator and move to test 3.
- Isolate unplug the front and tail lamp clusters one at a time and test drive, turn the main lights on and off looking for any improvement change due to each lamp cluster being disconnect isolated.
- If no improvement found, then isolate each front and rear lamp cluster via the fuses and repeat test procedure item 3. above.
With reference to and read the whole threads to the end;
With reference to;
http://www.micra.org.uk/threads/very-slow-acceleration-k12.59307/
http://www.justanswer.com/uk-nissan/6o13w-nissan-micra-k12-lights-causing-power-los
ECU limits engine power automatically if it has input indication that any brakes are on. This may be due to an electrical fault such as wet/condensation in wiring and electrical can-bus assemblies anywhere, as well as ABS brakes and electronic stability control circuits. Common sources are loose /corroded/waterlogged rear tail lamp cluster PCB can bus assemblies, fog lamps, number plate lamps, & indicators. Also firewall bulkhead rainwater leaks, possibly from incorrectly installed pollen filters, leaking down onto ECU modules located under the dashboard area.
Reference:
http://www.honestjohn.co.uk/forum/post/index.htm?t=64231
Cars stuck in limp mode-check reverse & brake lights are working-check cruise control as it is linked to brake light/reverse switches and fuses.
Reference:
http://www.efispares.com.au/tradetips.aspx
All of the above test sequence, to reveal possible sources of
on load engine control ECU errors, can be carried out by a competent DIY person with minimal equipment and at little or no cost, just time, perseverance & motivation to save money.
You appear to have tried all the obvious related items to e
ngine control and rev limiting, however the ECU is connected to many circuits, both directly and indirectly via can-bus data coms, and a fault in any one or combination of them anywhere on the vehicle can interfere with normal ECU operation and thus engine control performance.
Let us know how this control ECU enigma pans out?