Throttle Valve Control Module -J338-, CHECKING: Notes

2012 Volkswagen Jetta TDI, 4D Sedan, Standard TransSECTION Notes

Observe all safety precautions: SAFETY PRECAUTIONS 

View clean working conditions: CLEAN WORKING CONDITIONS 

Use only gold-plated terminals when servicing any component with gold-plated electrical harness connector terminals.

For wiring diagrams, component locations, and connector views, Refer to the applicable wiring diagram.

Special tools and workshop equipment required 

  • Multimeter
  • Wiring diagram

Test requirements 

  • The fuses OK
  • The battery voltage at least 12.5 V
  • All electrical consumers switched off
  • A/C switched off
  • The ignition switched off
  • Vehicles with automatic transmission, shift selector lever in park or neutral
  • Ground connections between engine/transmission/chassis OK
  • Throttle valve must not be damaged or dirty

Test procedure 

-- Perform a preliminary check to verify the customers complaint. Refer to PRELIMINARY CHECK 

Start diagnosis 

-- Connect the scan tool.

-- Switch ignition on.

-- Using the scan tool, check the throttle valve position (absolute) at idle stop:

Diagnostic text Specified value
Throttle valve position (absolute)  
  • Idle stop
3.0 to 25.0%

-- Slowly depress the accelerator pedal to Wide Open Throttle (WOT) stop while observing the percentage display. The percentage display must increase uniformly.

-- Using the scan tool, check the throttle valve position (absolute) at Wide Open Throttle (WOT) stop:

Diagnostic text Specified value
Throttle valve position (absolute)  
  • Wide Open Throttle (WOT) stop
84.0 to 97.0%

-- Switch ignition off.

If specified values are obtained: 

-- Fault may be intermittent.

-- Check for loose or corroded connections and any leaks in the Intake system.

-- Check Freeze Frame data for conditions when the DTC set.

-- Go to Final procedures

If the specified values are not obtained: 

-- Remove the throttle valve control module far enough so that the electrical connector can be reached.

-- Disconnect the Throttle Valve Control Module -J338- electrical connector.

-- Using a Multimeter, Check the Throttle Valve Control Module -J338- electrical harness connector terminal 1 to 2 to for voltage.

Specified value: Battery Voltage

-- Switch the ignition OFF.

-- Continue test according to the following table:

Value Cause Test
If the specified value was not obtained: Open or shorted circuit Checking wiring 
If the specified value was obtained: Check reference signal circuit Checking wiring 
RENDER: 1.0x

NO RELATED

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When to See a Mechanic

Stop DIY work and contact a certified mechanic immediately if any of the following apply:

  • You smell fuel, burning insulation, or see smoke.
  • Brakes feel soft, pull hard to one side, or make grinding noises.
  • The engine overheats, stalls repeatedly, or misfires under load.
  • You are missing required tools, torque specs, or safe lifting equipment.
  • You are not confident in the next step or safety outcome.