Powertrain, generic (extended)

P2652 "B" Rocker Arm Actuator System Stuck On (Bank 1)

Check engine lightOn
EmissionsRelevant
Drive cycleRequired
Limp modePossible

P2652 means the controller thinks stage B of the bank 1 rocker switching stays engaged after release was commanded, usually because the confirming oil pressure switch still signals pressure. Honda documents it in two ways. For the 2017 Odyssey, Pilot and Ridgeline and the 2017 Acura MDX, RDX, RLX and TLX, Honda dealer messages from 2021–22 describe it as a stuck-on fault of rocker arm oil pressure switch B on bank 1, often stored together with P3400 for the cylinder-pausing Valve Pause System; owners may notice uneven running, and Honda asked dealers to hold such cars for inspection. Bulletin 13-021 for older four-cylinder i-VTEC models instead treats P2647/P2652 as a high-voltage fault in the switch circuit. A solenoid leaking oil while off also fits.

Likely causes

Rocker arm oil pressure switch B reporting pressure permanently
Solenoid B lets oil through in its closed position
Locking pin stuck in the engaged position
Switch signal line shorted to voltage (Honda four-cylinder meaning)

Symptoms

  • MIL on, possibly together with P3400 on Honda V6
  • Rough or uneven running, especially at low load
  • Cylinder deactivation no longer works

Repair estimate

DifficultyMediumDIY possible
Parts and labour€40–900
Time0.3–4 h

Typical range across vehicles; the real cost depends on what the testing finds.

Parts involved

rocker arm actuator b b1oil control valveoil pressure switch

Related codes

P2651P2650P2647P2662P3400

References: static.nhtsa.gov, static.nhtsa.gov, static.nhtsa.gov, law.cornell.edu.