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EMRSR, Certified Service Manager
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Experience:  30 years dealership experience
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2005 Saab 9-3 Arc: My local mechanic..DTC..position sensor..throttle

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My local mechanic tells me my 2005 Saab 9-3 Arc is throwing a P2135 DTC, which means either the acclerator pedal position sensor or the throttle plate position sensor is kaput. Most of what I garner from various forums is that P2135 points more to the TB than the pedal. Can you enlighten me?
Thanking you.

I go with his diagnostics at this point if he looked at the data.



P2135 00

Throttle Position Sensor Circuit, Plausibility Fault between Circuit 1 and 2

Fault symptom

  • Check Engine
  • Cruise control not working.
  • Limp home

On-board diagnosis

Type of diagnosis:

  • Continuous

Enable criteria:

  • When the ECM is awake, diagnosis is active (even with the ignition off).
  • NONE of the following DTCs must be detected:
  • P0122, P0123, P0222, P0223

Fault criteria:

  • When the difference in voltage between throttle position sensors 1 and 2 is 4 - 8%, depending on the position of the throttle (4% for unactuated pedal, 8% for fully depressed pedal).


  • 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 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:

  • Throttle Position Sensor 1
  • Throttle Position Sensor 2 (See also description of readings/activations in diagnostic tool)
Customer: replied 6 years ago.

Perhaps I did not ask my question correctly.

The mechanic tells me it could be the accelerator pedal assembly, for which he wants about $100 to remove, inspect, clean and reinstall...OR...the throttle body with integral plate position sensor, for which he wants me to get rid of the car, stating that even dealers cannnot obtain this part anymore (two Saab dealers, one in Maryland and one in Delaware, will not give me a straight answer). Does P2135 point specifically to one or the other?

Thanking you again.

Ok, I did not interperet it correct either, if he has not done the inspection or testing I would point more to the ETB, or wiring to the TP sensors, thats where the discrepancy is.... between the sensors. If it turns out to be the ETB, there are plenty of used units out there. Go to and do some shopping, you can look local or regionally, they have the largest locater for used parts. I have included a couple of screen captures for you as well.





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Customer: replied 6 years ago.
Thank you for exemplary service.
You are welcome ...thanks !

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