Back to 1999 BMW 540iT E39

1999 BMW 540IT E39

4.4L V8RWDAUTOMATICgas
Repairs0Labor593Torque2592Fluid7DTC649Battery0Maintenance0Recalls0
P1415moderate severityPowertrain

Secondary Air System Bank 1

on 1999 BMW 540iT E39 4.4L V8 · RWD

What this code means

The DME detected a malfunction in the secondary air injection system for Bank 1. The secondary air system pumps fresh air into the exhaust manifold during cold starts to reduce hydrocarbon emissions.

Symptoms

  • Check Engine Light
  • Failed emissions test
  • Rough cold start idle
  • Unusual noise from air pump on startup

Common causes

  • Faulty secondary air pump
  • Secondary air valve stuck closed
  • Clogged air passages in exhaust manifold
  • Faulty secondary air pump relay
  • Check valve failure

Diagnostic steps

  1. Listen for air pump operation during cold start
  2. Test air pump relay
  3. Check for voltage at air pump connector
  4. Inspect air passages for carbon blockage
  5. Test air pump by direct power application

Repair notes

Replace faulty secondary air pump or clean clogged air passages in the exhaust manifold.

Other Powertrain codes on this vehicle

Building an app?
Free API access to all this data — 50 requests/day, no card required.
Get an API key →
Run a shop?
Manage repairs, estimates, and customers with ShopBase — $249/mo, all features included.
Try ShopBase →