Engine-Codes - Generic - P121C

P121C - Cylinder Balance Test Injector Leaking

Repair Importance Level: 3/3
Repair Difficulty Level: 3/3  What is this?
Table of contents

P121C Possible Causes

  • Faulty Fuel Injector
  • Fuel Injector harness is open or shorted
  • Fuel Injector circuit poor electrical connection

How is the P121C code repair?

Start by checking the "Possible Causes" listed above. Visually inspect the related wiring harness and connectors. Check for damaged components and look for broken, bent, pushed out, or corroded connector's pins.

What is the cost to diagnose the P121C code

Labor: 1.0

The cost to diagnose the P121C code is 1.0 hour of labor. The auto repair labor rates vary widely across the country, and even within the same city. Most auto repairs shops charge between $75 and $150 per hour.

Possible Symptoms

  • Engine Light ON (or Service Engine Soon Warning Light)

P121C Meaning

The Powertrain Control Module (PCM) monitors the Fuel Injector. The PCM sets the OBDII code when the Fuel Injector is not to factory specifications.

More Information

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Information for specific makes

  • P121C BMW Nitrogen Oxide Sensor Heating Activation Short Circuit
  • P121C FORD Cylinder Balance Test Injector Leaking
  • P121C MINI Nitrogen Oxide Sensor Heating Activation Short Circuit

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