28C8

28C8 - P054B

Information saved in
DME

Fault code
28C8 - P054B

Fault text
VANOS, exhaust: Actuator movement

Fault description
During the catalyst-heating phase the diagnostic function
monitors the exhaust camshaft for adequately precise
angular positioning in accordance with the specified angle.

Condition for fault identification
Test condition:
Engine running in catalyst warmup phase
Terminal condition: Terminal 15
Voltage condition:
none

Condition for fault memory entry
2.5 sec.

Action in service
1. If a fault related to the camshaft sensor is present, repair
this first
2. Check the connections (contact resistance, corrosion)
between camshaft actuator and DME. Determine whether
UBatt is present at actuator and conduct system test with
tester
3. Check oil level/oil pressure
4. Check camshaft valves for contamination
Camshaft solenoid valves mutual position switch
If this is successful: Replace exhaust-side solenoid valve
5. No improvement after 4.: Switch positions of VANOS
units. If this is successful: Replace exhaust-side VANOS
unit

Fault effect and breakdown warning
None
Engine runs poorly

Driver information
Warning light:
MIL ON (US only)
CC message: Electronic reduction in engine output (ID 29)
VVT in emergency default mode and no boost

Service instruction
None