E39 / P0121 00

Read the instructions below then start the fault diagnostic procedure.

Symptom: Malfunction Indicator Lamp Performance loss.

P0121 00

Fault symptom

Malfunction Indicator Lamp

Performance loss.

On-board diagnosis

Type of diagnosis:

Continuous

Enable criteria:

The following diagnostic trouble codes may not be generated:

P0102, P0103

P0107, P0108

P0112, P0113

P0117, P0118

P0335, P0336

Engine running.

Fault criteria:

ECM registers that the signal from the throttle position sensor 1 has jammed.

System reaction to a fault:

Limp home

OK report:

Fault criteria NOT fulfilled.

Fault handling:

Type III

(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.

The total of sensor 1 & 2 should be ~5 V.

Functions in the diagnostic tool related to the fault:

Test value:

•	Throttle Position Sensor 1

•	Throttle Position Sensor 2

(See also description of readings/activations in diagnostic tool)