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Discussion Starter · #1 ·
I have a 2009 Scion tC and it will start and idle but doesn't respond to me pushing on the gas pedal. We plugged in an ECU and the only codes we got were C1238 C1329 C0215 C0210 and C1249 None of which seem to have anything to do with acceleration. Any help would be greatly appreciated I would rather not take it to a shop as I am strapped on cash!
 

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Have you checked the Throttle Cable (from accelerator pedal to the throttle on the engine to make sure it's not broken?).
Also, I would think that the Throttle Position sensor could be part of the picture here.
I have a 2005 TC, so it may be a bit different... but looked in the 2005 Toyota/Scion factor service manual for those codes.
All of the codes you listed are Chassis Codes (for things like wheel speed sensors for ABS, and open stop light circuit.
I find it odd that a vehicle would have so many chassis codes set.
Did you check your scan tool to make sure you are reading ECU codes correctly through the OBD port?
 

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Discussion Starter · #3 ·
I actually had a friend that had a scanner so he came over and did it but I believe we had the correct port. I will check the cable and see about the sensor when its a little less snowy. thank you
 

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Actually my mistake, I looked through the 2005 TC service manual some more.
It turns out, there is actually no throttle cable after all. (See information below from part of the manual).
Most generic OBD scan tools should allow you to monitor the Throttle Position Sensor (TPS) voltage.
That's where I would start .. by trying to monitor the voltage of the TPS for different Accelerator pedal positions.

Related Codes appear to be something like P2119, P2120-P2123, P2125,7,8, P2138.
It's interesting to see that there is a Fail-Safe mode as well.

Of course, it would be useful to have the service manual. it steps through the diagnostics flow...

from the manual:
This ETCS (Electronic Throttle Control System) does not use a throttle cable.

The Accelerator Pedal Position (APP) sensor is mounted on the accelerator pedal bracket and has 2 sensor
circuits: VPA1 (main) and VPA2 (sub). The voltage, which is applied to terminals VPA1 and VPA2 of the ECM,
varies between 0 V and 5 V in proportion to the operating angle of the accelerator pedal (throttle valve). A
signal from VPA1 indicates the actual accelerator pedal opening angle (throttle valve opening angle) and
is used for engine control. A signal from VPA2 conveys the status of the VPA1 circuit and is used to check
the APP sensor itself.
The ECM monitors the actual accelerator pedal opening angle (throttle valve opening angle) through the
signals from VPA1 and VPA2, and controls the throttle actuator according to these signals.

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FAIL–SAFE
When any of DTCs P2120, P2121, P2122, P2123, P2125, P2127, P2128 and P2138 are set, the ECM enters
fail–safe mode. If either of the 2 sensor circuit malfunctions, the ECM uses the remaining circuit to calculate
the accelerator pedal position to allow the vehicle to continue driving. If both of the circuits malfunction,
the ECM regards the accelerator pedal as being released. As a result, the throttle valve is closed and the
engine idles.
Fail–safe mode continues until a pass condition is detected, and the ignition switch is turned to OFF.
 

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CIRCUIT DESCRIPTION
The Electronic Throttle Control System (ETCS) is composed of the throttle actuator, Throttle Position (TP)
sensor, Accelerator Pedal Position (APP) sensor, and ECM. The ECM operates the throttle actuator to regulate
the throttle valve in response to driver inputs. The TP sensor detects the opening angle of the throttle
valve, and provides the ECM with feedback so that the throttle valve can be appropriately controlled by the
ECM.

Also, looking on parts web sites, I see that this vehicle lists "accelerator pedal position sensor" (inside the car, senses position of the pedal) to give you more idea of what that looks like.
Getting a OBD Scan "P" (powertrain) rather than Chassis codes would be a big help here as well as a scan of the TPS voltage.
 
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