Fault Family System: Powertrain (P-Codes) 20 SAE Codes

Cylinder Deactivation Valve Performance

Diagnostic & Technical Explanation

Code P2CDB (Cold Start Cylinder 1 Deactivation/Intake Valve Control Performance) sets when a deactivation-capable cylinder's intake valve does not follow its commanded active/deactivated state within the expected time, whether reported per cylinder, as a whole-system check on a bank, or during the cold-start window when oil is thickest and switching pressure builds slowest. Because the valve's own control circuit tests fine when this code sets, the fault points at the mechanical or hydraulic side: aerated or degraded oil that cannot build switching pressure quickly, a lifter pin sticking partway through its travel, or oil gallery varnish slowing the response.

These 20 diagnostic trouble codes share one detection mechanism and one repair path, which is why MechanicDB groups them into a single authored fault family rather than repeating the same explanation 20 times.

Codes in this family (20)

Code	Definition	Repair coverage
P2CDB	Cold Start Cylinder 1 Deactivation/Intake Valve Control Performance	4 ranked fixes
P2CDC	Cold Start Cylinder 2 Deactivation/Intake Valve Control Performance	4 ranked fixes
P2CDD	Cold Start Cylinder 3 Deactivation/Intake Valve Control Performance	4 ranked fixes
P2CDE	Cold Start Cylinder 4 Deactivation/Intake Valve Control Performance	4 ranked fixes
P2CDF	Cold Start Cylinder 5 Deactivation/Intake Valve Control Performance	4 ranked fixes
P2CE0	Cold Start Cylinder 6 Deactivation/Intake Valve Control Performance	4 ranked fixes
P3400	P34C8	4 ranked fixes
P3497	Cylinder Deactivation System Bank 2	4 ranked fixes
P3498	Cylinder 1 Deactivation/Intake Valve Performance	4 ranked fixes
P3499	Cylinder 2 Deactivation/Intake Valve Performance	4 ranked fixes
P349A	Cylinder 3 Deactivation/Intake Valve Performance	4 ranked fixes
P349B	Cylinder 4 Deactivation/Intake Valve Performance	4 ranked fixes
P349C	Cylinder 5 Deactivation/Intake Valve Performance	4 ranked fixes
P349D	Cylinder 6 Deactivation/Intake Valve Performance	4 ranked fixes
P349E	Cylinder 7 Deactivation/Intake Valve Performance	4 ranked fixes
P349F	Cylinder 8 Deactivation/Intake Valve Performance	4 ranked fixes
P34A0	Cylinder 9 Deactivation/Intake Valve Performance	4 ranked fixes
P34A1	Cylinder 10 Deactivation/Intake Valve Performance	4 ranked fixes
P34A2	Cylinder 11 Deactivation/Intake Valve Performance	4 ranked fixes
P34A3	Cylinder 12 Deactivation/Intake Valve Performance	4 ranked fixes

What this page does not show

This page publishes the fault mechanism and the code index. The licensed dataset adds, for every one of the 15,886 codes, the full authored repair set (56,729 procedures in total) with the fields deliberately withheld here:

Procedures 2..n after the first-listed procedure
Aftermarket parts cost ranges in USD (est_parts_cost_min/max_usd)
Professional labor-hour estimates (est_labor_hours)
Step-by-step diagnostic and repair instructions
Replacement-part mappings and catalog lookups
6,637 manufacturer-specific OEM codes across 32 makes ($149 tier)

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