P0638

P0638 00

Throttle Mechanical, Throttle Position Deviation from Demanded







Fault symptom
Check Engine
Cruise control not working.
Limp home

On-board diagnosis

Type of diagnosis:
Continuous

Enable criteria:
Ignition ON.

Fault criteria:
When current throttle position deviates 10% from the requested position.

Dependent
None

System reaction to a fault:
Correction of mass air flow/combustion for fuel calculation is blocked.
Limited acceleration and idle function.
Cruise control blocked.
Secondary air switched off.

OK report:
Fault criterion not fulfilled and vehicle speed over 0 km/h for more than 60 s.

Fault handling:
Type III
(See Description of On-Board Diagnostics/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.

IMPORTANT:
- The diagnostic trouble code can also be generated due to fault in connector H42-2 (pin 13, 14, 17, 18, 19 and 20).

Functions in the diagnostic tool related to the fault:
Test value:
- Throttle Position Sensor 1
- Throttle Position Sensor 2

Activation:
- Throttle Position Test