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EGR Cooler Switch Over Valve 1-2 Checking

Observe all safety precautions: SAFETY PRECAUTIONS 

View clean working conditions: CLEAN WORKING CONDITIONS 

Perform a preliminary check to verify the condition: 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 and workshop equipment required 

Test conditions 

NOTE:

The EGR Cooler Switch Over Valve 1-2 are solenoids that control vacuum motors to each EGR cooler (main and auxiliary). The N345 (solenoid) is located on top of the engine to the left (drivers side) of center. N 381 (solenoid) is located on the left (drivers side) at the rear of the cylinder head.

Test procedure 

-- Disconnect the EGR Cooler Switch Over Valve 1 or 2 -N345/N381- harness connector.

-- Turn the ignition switch ON.

-- Measure the resistance of the 2 terminals of the EGR Cooler Switch Over Valve 1 or 2 -N345/N381- connector.

Specified value: 35.2 ohms (+/- 6 ohms).

If the specified value was not obtained:

-- Replace the EGR Cooler Switch Over Valve 1 or 2 -N345/N381-. Refer to the Repair information.

If the specified value was obtained:

Checking voltage 

-- Connect the voltmeter to terminal 1 of the EGR Cooler Switch Over Valve 1 or 2 -N345/N381- harness connector and ground black lead to engine ground.

Specified value: 11.60 V (+/- 1.5 V).

If the specified value was obtained:

-- Connect the voltmeter to terminal 2 of the EGR Cooler Switch Over Valve 1 or 2 -N345/N381- harness connector and ground black lead to engine ground.

Specified value: 3.48 V (+/-.5 V).

If any of the specified values were Not obtained:

Checking wiring 

-- Remove the Motronic Engine Control Module (ECM) -J623-. Refer to the Repair information.

-- Using a multimeter, check the EGR Cooler Switch Over Valve 1 or 2 -N345/N381- electrical harness connector terminals to the Motronic Engine Control Module (ECM) -J623- electrical harness connector T94 connector for resistance.

Component EGR Cooler Switch Over Valve -- electrical harness connector terminals Motronic Engine Control Module (ECM) -J623- electrical connector terminals or fuse location
EGR Cooler Switch Over Valve 1 -N345- 1 Fuse S-10
2 T94/47
EGR Cooler Switch Over Valve 2 -N381- 1 Fuse S-10
2 T94/49

Specified value: 1.5 ohms Max.

If any of the specified values were Not obtained:

-- Check the wires for a short circuit to each other, a short to battery voltage, or a short to ground.

-- Check the electrical harness connector for damage, corrosion, loose or broken terminals.

-- Repair as necessary.

If no malfunction is detected in electrical circuit and the voltage was Not obtained:

-- Replace the Motronic Engine Control Module (ECM) -J623-. Refer to the Repair information for removal and installation procedures.

Final procedures 

After the 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 .
  2. If necessary, erase the DTC memory. Refer to DIAGNOSTIC MODE 04 - ERASE DTC MEMORY .
  3. If the DTC memory was erased, generate readiness code. Refer to READINESS CODE .