Powertrain, generic · Vehicle speed, idle control and auxiliary inputs

P054B Cold Start B Camshaft Position Timing Over-Retarded Bank 1

Check engine lightOn
EmissionsRelevant
Drive cycleRequired
Limp modeNo

Camshaft B is the exhaust camshaft. During catalyst heating after a cold start some engines set it to a specific position; CARB requires such commanded elements to be monitored with their own codes, separate from the normal cam codes. Ford watches the deviation with an averaged variance index for each direction; GM (Saab 9-4X V6) uses only the retard codes, above 6° for 1 s or 4 s cumulative, type B. The commonest cause is oil pressure building too slowly when cold. P054B means bank 1 stayed too far retarded. GM's test procedure checks oil level and pressure, a phaser sweep from 0 to 40° and the control valve at 7–12 Ω.

Likely causes

Oil pressure building too slowly when cold (oil level, viscosity, pick-up, pump)
Exhaust oil control valve sticking or screens clogged
Module software (threshold too tight)
Cam phaser defective, locking pin
Timing chain stretched or misassembled

Symptoms

  • Check engine light on, usually without noticeable symptom
  • Brief rattle on cold start
  • Rough idle while warming up

Repair estimate

DifficultyMediumWorkshop job
Parts and labour€80–1,200
Time0.5–8 h

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

Parts involved

exhaust camshaft phaservct oil control valveengine oilengine control module

Related codes

P054AP054DP0015P052BP0013P0521

References: saabwisonline.com, newtonnet.co.uk, law.cornell.edu.