Knock Sensor/ Failure

[phatty]

So i got the 21 code which according to my chart is knock sensor failure, which then proceeded to put my sled in code 23 which is limp mode, which really sucked in 4 feet of fresh snow...

Anyone know what causes the sensor failure? Bad gas? Or am i really getting close to detonation? Do these sensors just go out sometimes?

Need to know where to look to identify the actual problem! Thanks guys!

 

[Dam Dave]

Mine has done it a time or 2, but would clear and run fine if I shut it off and restarted it, 2009 M8, my 08 M8 did it twice to. but it has always cleared

 

[PowderBrad]

Not to hijack,

but anyone have a handy dandy sheet of all the codes that may be flashed? (something I can print out)

Thanks,

 

[MUZBOMB]

Hey buddy has a 07 M8 and his code comes up to, but same thing if he shuts it off it will go away for the rest of the day. It only comes once then if you shut if off it will be good for the whole day. Is this a concern will something happen if he doesn't get it fixed? Thanks guys:beer;

 

[phatty]

Not to hijack,

but anyone have a handy dandy sheet of all the codes that may be flashed? (something I can print out)

Thanks,

the codes are listed on the clutch side of the airbox.

i also have the 09 M8... sounds like the sensors are sketchy at best for reliability... maybe i will just replace the sensor and hope for the best

 

[RACINSTATION]

Running lean will cause this. They are really touchy on the pump gas turbos and seem to be set off a lot there. Unscrew it from the head and tie it up out of the way and see if you still get the code running it under a heavy load. If not, then you are detonating or running lean. If you still get the code, then the sensor is bad. I have seen a lot of them go off, and only a few of them were bad sensors.

 

[m8magicandmystery]

Not to hijack,

but anyone have a handy dandy sheet of all the codes that may be flashed? (something I can print out)

Thanks,

Check Engine Light
(Crossfire/F-Series/
M-Series Models)
The Check Engine Light is controlled by the ECU and
may illuminate for a number of reasons. The light
should illuminate each time the key is turned to RUN
or START, and it should go out when the engine starts.
If the light stays illuminated or it illuminates while the
engine is running, the ECU is receiving input that is
outside of its established parameters.
Diagnostic Codes/
Check Engine
(Crossfire/F-Series/
M-Series Models)
These diagnostic codes are flashed by the check engine
light incorporated within the speedometer/tachometer.
Refer to the following chart for diagnostic code
sequences.
NOTE: On single-digit codes (2, 4, etc.), the number
indicated will flash in an uninterrupted
sequence. On double-digit codes (1-2, 1-6, etc.), the
first number indicated will flash in an uninterrupted
sequence, there will be a short pause, and the second
number indicated will flash in an uninterrupted
sequence.
If the coolant temperature is at or above 80° C (176°
F), the coolant temperature light will flash a warning
(alert). If the coolant temperature is at or above 93° C
(200° F), the coolant temperature light will cease flashing
and will remain constantly illuminated.
Number of Flashes Trouble
1-2
(Check Engine Light)
Failure in ignition coil.
1-6
(Check Engine Light)
Incorrect adjustment/failure in
APV cable.
1-7
(Check Engine Light)
Failure in exhaust temperature
sensor.
1-8
(Check Engine Light)
Failure in servomotor.
2
(Check Engine Light)
Failure in injector(s).
2-1
(Check Engine Light)
Failure in knock sensor.
2-3
(Check Engine Light)
Failure in knock control system.
4
(Check Engine Light)
Open or short circuit in barometric
pressure sensor.
5
(Check Engine Light)
Open or short circuit in intake air
temperature sensor.
6
(Check Engine Light)
Open or short circuit in water
temperature sensor.
7
(Check Engine Light)
Open or short circuit in throttle
position sensor.
Steady Flash
(Coolant Temperature Light)
Coolant Temperature Above 80°
C (176° F).
Constant On
(Coolant Temperature Light)
Coolant Temperature Above 93°
C (200° F).



Diagnostic Codes/
Chassis Control Unit
(Crossfire/F-Series/
M-Series Models)
These diagnostic codes are flashed by the wrench icon
light incorporated within the speedometer/tachometer.
Refer to the following chart for diagnostic code
sequences.
NOTE: On these double-digit codes (3-1, 3-2, etc.),
the first number indicated will flash in an uninterrupted
sequence, there will be a short pause, and
the second number indicated will flash in an uninterrupted
sequence.
Number of Flashes Trouble
3-1
(CCU Icon)
Stator failure
(input open or shorted).
3-2
(CCU Icon)
High power DC output deactivated
(headlight/handwarmer).
3-3
(CCU Icon)
High power DC output shorted
(headlight/handwarmer).
3-4
(CCU Icon)
Low power DC output deactivated
(gauge/taillight/APV valves).
3-5
(CCU Icon)
Low power DC output shorted
(gauge/taillight/APV valves).
3-6
(CCU Icon)
System under voltage
(below 11 volts).
3-7
(CCU Icon)
System over voltage.
(above 15.5 volts).
3-8
(CCU Icon)
Gear shift actuator failure
(over current or over temperature).
4-2
(CCU Icon)
Tachometer input failure (engine running
- no tachometer
signal present).
4-3
(CCU Icon)
Gear position switch failure (did not
change - no (or invalid)
position input).
4-4
(CCU Icon)
CCU over temperature
(above 105° C - 221° F).