Not sure about the 20 part, but here's the list of codes from the '07 service manual...
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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.
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.
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Number of Flashes
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).
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Engine Codes
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.
Number of Flashes
1-2 = Failure in ignition coil.
1-6 = Incorrect adjustment/failure in APV cable.
1-7 = Failure in exhaust temperature sensor.
1-8 = Failure in servomotor.
2 = Failure in injector(s).
2-1 = Failure in knock sensor.
2-3 = Failure in knock control system.
4 = Open or short circuit in barometric pressure sensor.
5 = Open or short circuit in intake air temperature sensor.
6 = Open or short circuit in water temperature sensor.
7 = 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).
