P120B Possible Causes
- Faulty secondary fuel injector, bank 1
- Secondary fuel injector harness 1 is open or shorted
- Poor electrical connection in secondary fuel injector circuit bank 1
How to Fix Code P120B?
Start by checking the “possible causes” listed above. Visually inspect the corresponding cable harness and connectors. Look for damaged components and check for broken, bent, pushed out, or corroded connector pins.
Possible Symptoms
- Engine light on (or engine service warning light soon)
P120B Meaning
The Powertrain Control Module (PCM) monitors the secondary fuel injector bank 1. The PCM sets the OBDII code when the secondary fuel injector bank 1 does not meet factory specifications.