Crankcase Vent Valve, Fault codes P2187 P2189 BMW 5 Series 2004 - 2010

Fault codes stored in vehicle

P2187 (29EF) Fuel mixture adaptation, sum check error

P2189 (29F0) Fuel mixture adaptation 2, sum check error

29E7 Fuel mixture adaptation, idling, per time unit

29E8 Fuel mixture adaptation 2, idling, per time unit

After a control unit interrogation using a BMW scan tool, we located high additive (5.0 both banks) numbers. The multiplicative numbers were great, both around 1.0.

High additive numbers indicate a problem at idle.

Since the engine was hot (at operating temperature) we chose not to perform a smoke leak test but connected our monometer (Slack Tube Tester), the crankcase vacuum was very high, (off the scale). We disconnected both vacuum vent valves on top of the valve covers and blocked the vacuum pipes to the throttle body eventually determining bank #1 to be the cause. We removed the suspect faulty bank #1 vacuum vent valve, it was torn (arrow).

You can buy just the vacuum vent valves (repair kit) PN 11.12.7.547.058 separately (low cost) from BMW. Now the crankcase vacuum reading is normal at around 7.75" of water.

We watched the additive numbers recover, reset the fault codes and then test drove the vehicle resetting the fuel trim adaptations.
After replacing the parts we test drove the vehicle and monitored Additive fuel trim. The numbers started to return to normal (0.1). Then we cleared fault codes and reset fuel trim adaptations.