21
UnclassifiedSpeed
What This Code Means
Possible engine misfire; Fuel and spark calculations not made while ECU attempts to resynchronize
Possible Causes
- •24 Pin (MSE 1.0) Plastic-Cased ECU: Pin circuits 9 and/or 10 routed near noisy electrical signals (coils, spark plug lead, plug connector)
- •24 Pin (MSE 1.0) Plastic-Cased ECU: Pin circuits 9 and/or 10 wiring or connectors problem
- •24 Pin (MSE 1.0) Plastic-Cased ECU: Shielding for pin circuits 9 and/or 10 damaged or not properly grounded
- •32 Pin (MSE 1.1) Plastic-Cased ECU: Pin circuits 9 and/or 10 routed near noisy electrical signals (coils, spark plug lead, plug connector)
- •32 Pin (MSE 1.1) Plastic-Cased ECU: Pin circuits 9 and/or 10 wiring or connectors problem
- •32 Pin (MSE 1.1) Plastic-Cased ECU: Shielding for pin circuits 9 and/or 10 damaged or not properly grounded
- •35 Pin (MA 1.7) Metal-Cased ECU: Pin circuits 3 and/or 21 routed near noisy electrical signals (coils, spark plug lead, plug connector)
- •35 Pin (MA 1.7) Metal-Cased ECU: Pin circuits 3 and/or 21 wiring or connectors problem
- •35 Pin (MA 1.7) Metal-Cased ECU: Shielding for pin circuits 3 and/or 21 damaged or not properly grounded
- •ECU-to-harness connection problem
- •Engine Speed Sensor / RPM Signal Failure
- •Engine speed sensor connector or wiring problem
- •Engine speed sensor loose or incorrect air gap
- •Flywheel key sheared
- •Non-resistor spark plug(s) used
- •Poor or improper grounds in system (battery, ECU, oxygen sensor, shielding, fuel pump, ignition output)
- •Speed sensor ring gear damaged teeth
- •Speed sensor ring gear varying gap (gear loose or out of alignment)
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