P01CA: Fuel Rail Pressure Too Low - Engine Cranking Bank 2

What does P01CA mean?

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. P01CA is the bank 2 counterpart of P00C6: during cranking the rail pressure on bank 2 does not rise quickly enough to the minimum needed to release injection. For bank 1 GM checks once per start that pressure exceeds about 3 MPa and does not fall below 2 MPa, with two trips. No manufacturer using exactly this code was found; GM's two-rail LT6 reports the same situation with the bank-neutral P00C6.

The code tells you which monitor failed, not which part is broken. Test before replacing parts.

Symptoms

• Check engine light on
• Long cranking or no start
• Rough running right after start

Common causes

• High High-pressure pump of bank 2 or its drive weak
• Medium Low supply pressure at start (lift pump, check valve)
• Medium Leak or leaking injector on bank 2
• Low Bank 2 rail pressure sensor or connector

Likelihood is a general estimate across vehicles; your make and model may differ.