Powertrain, generic · Fuel and air metering

P01C8 Fuel Rail/System Pressure - Too Low Bank 2

Check engine lightOn
EmissionsRelevant
Drive cycleRequired
Limp modePossible

Some V engines have a separate high-pressure fuel circuit per bank, each with its own pump or rail – for example Audi's 4.0 TFSI V8 with a second high-pressure pump for bank 2. These codes are the bank 2 counterparts of the system pressure codes for bank 1. P01C8 is the bank 2 counterpart of P0087: the actual pressure stays below target over time. Typical causes are a weak high-pressure pump on bank 2, a faulty volume control valve, low supply pressure or a leak. No manufacturer using exactly this code was found; the logic follows P0087 and CARB's requirement for pressure control. Not every two-rail engine uses them: GM's LT6 reports bank 2 pressure problems under other codes.

Likely causes

High-pressure pump of bank 2 weak or worn
Volume control valve faulty or its control disturbed
Supply pressure too low (lift pump, filter)
Leak in the bank 2 high-pressure circuit

Symptoms

  • Check engine light on
  • Loss of power or limp mode
  • Hard starting, misfires on bank 2

Repair estimate

DifficultyHardWorkshop job
Parts and labour€150–1,500
Time1–4 h

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

Parts involved

high pressure fuel pump bank2fuel volume control valvefuel rail bank2

Related codes

P0087P01C9P01CAP01BF

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