Electronic Throttle Control Module: Testing and Inspection
Throttle Valve Control Module, Checking
Observe all safety precautions: => [ Safety Precautions ] Safety Precautions
View clean working conditions: => [ Clean Working Conditions ] Clean Working Conditions
Prior to repair work, perform a preliminary check to verify the condition. Refer to => [ Preliminary Check ] Preliminary Check.
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, testers and auxiliary items required
• Multimeter
• Wiring diagram
Test requirements
• The engine control module 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
- Connect the scan tool.
- Switch ignition on.
- Using the scan tool, check the Throttle valve position (absolute) at idle stop:
- Switch ignition off.
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 electrical connector.
Checking internal resistance
• The correct polarity of the ohm meter leads MUST be maintained or the results of the Throttle Valve Control Module diagnosis will be incorrect.
- Using a multimeter, connect the Black lead to terminal 1 and the Red lead to terminal 2 of the Throttle Valve Control Module (J338).
- Measure the internal resistance of the throttle valve control module.
Specified value: 2.6 - 3.0 M ohms
- Using a multimeter, connect the Black lead to terminal 4 and the Red lead to terminal 3 of the Throttle Valve Control Module (J338).
Specified value: 10.8 - 12.9 M ohms
If any of the specified values were not obtained or the valve is binding or sticking:
- Replace the Throttle Valve Control Module (J338).
If the specified values were obtained:
Checking voltage supply and wiring
- Switch the ignition on.
- Using a multimeter, measure the voltage between terminal 1 and 2 of the Throttle Valve Control Module (J338) electrical harness connector.
Specified value: 11.91 V (+/- 1.2 V)
- Using a multimeter, measure the voltage between terminal 1 and 3 of the Throttle Valve Control Module (J338) electrical harness connector.
Specified value: 3.47 V (+/- 1 V)
- Using a multimeter, measure the voltage between terminal 1 and 4 of the Throttle Valve Control Module (J338) electrical harness connector.
Specified value: 11.64 V (+/- 1.5 V)
If the specification was not obtained:
- Switch the ignition off.
- Using a multimeter, measure the resistance of the circuits between the throttle valve control module and the engine control module or specified location. Refer to the applicable wiring diagram.
Specified value: 1.5 ohms Max.
If the specification was Not obtained:
- Check the wires for high resistance, a short circuit to battery voltage or short to ground.
- Check the electrical harness connector for damage, corrosion, loose or broken terminals.
- Repair as necessary.
If no malfunction is detected in the wiring and the voltage supply was Not OK:
- Replace the Motronic Engine Control Module (ECM) (J623). Refer to the repair information.
Final procedures
After repair work, the following work steps must be performed in the following sequence:
1. Check the DTC memory. Refer to => [ Diagnostic Mode 03 - Read DTC Memory ] Diagnostic Modes 01 - 0A.
2. If necessary, erase the DTC memory. Refer to => [ Diagnostic Mode 04 - Erase DTC Memory ] Diagnostic Modes 01 - 0A.
3. If the DTC memory was erased, generate readiness code. Refer to => [ Readiness Code ] Readiness Code.