Charge Air Cooler Bypass Control Unit

Charge Air Cooler Bypass Control Unit

Observe all safety precautions: => [ Safety Precautions ] Generic Scan Tool

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

Test procedure

- Disconnect the Charge Air Cooler Bypass Control Unit electrical connector.

Checking internal resistance

• The correct polarity of the ohm meter leads MUST be maintained or the results of the Charge Air Cooler Bypass 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 Charge Air Cooler Bypass Control Unit (J865).

- Measure the internal resistance of the Charge Air Cooler Bypass Control Module.

Specified value: 2.1 - 2.5 M ohms

- Using a multimeter, connect the Black lead to terminal 4 and the Red lead to terminal 3 of the Charge Air Cooler Bypass Control Unit (J865).

Specified value: 16.6 - 18.0 M ohms

If any of the specified values were not obtained or the valve is binding or sticking:

- Replace the Charge Air Cooler Bypass Control Unit (J865).

If the specified values were obtained:

Checking wiring

- Using a multimeter, measure the resistance of the circuits between the Charge Air Cooler Bypass Control Unit and the Motronic Engine Control Module (ECM) 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 motor resistance check was OK:

- Replace the Motronic Engine Control Module (ECM) (J623). Refer to the Repair Manual.

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 - 09.

2. If necessary, erase the DTC memory. Refer to => [ Diagnostic Mode 04 - Erase DTC Memory ] Diagnostic Modes 01 - 09.

3. If the DTC memory was erased, generate readiness code. Refer to => [ Readiness Code ] Programming and Relearning.