T8 / P0030 00
Read the instructions below then
start the fault diagnostic procedure.
Symptom: CHECK ENGINE
O2S 1 Preheater Circuit Performance Problem

Fault symptom
CHECK ENGINE
On-board diagnosis
Type of diagnosis:
Enable criteria:
Battery voltage must be between 11 - 16 V. |
NONE of the following DTCs must be detected: |
Fault criteria:
When current is below 300 mA for more than 10 s. |
Dependent:
System reaction to a fault:
Preheating of oxygen sensors 1 and 2 is stopped. |
Fuel adaption is blocked. |
Adaption of rear oxygen sensor is blocked and reset. |
OK report:
When fault criteria NOT fulfilled for 11 s. |
Fault handling:
(See section Fault handling III, "Other emission-related components and functions" for more information.) |
Checking the wiring harness
Move the wiring harness at several spots and in several directions to reveal intermittent breaks and short-circuits. Check switches, connectors and crimp connections for oxidation, retracted pins and pin clamping force.
Diagnostic help
Diagnosis regards:
Electrical fault in connecting leads or component. |
Functions in the diagnostic tool related to the fault:
(See also description of readings/activations in diagnostic tool) |