NOTE: EDS control unit is referred to as N39 by the manufacturer. When diagnosing EDS, test connections are made at EDS control unit (N39) using Contact Box (124 589 00 21 00).

For reading and understanding fault code diagnosis, as an example, using DIAGNOSTIC TESTS, read 2 under IMPULSE READOUT column. Read step 2.0 under TEST STEP/TEST SCOPE column. Component being tested is fuel rack position sensor (L7). Under TEST CONNECTION column, using DVOM, measure resistance between contact box (N39) terminals No. 4 and 5. Under TEST CONDITION column, make measurement with ignition off and EDS control unit disconnected. Resistance is 46-54 ohms under NOMINAL VALUE column. If resistance is not within specification, follow instructions under POSSIBLE CAUSE/REMEDY column.

Using one other example, read 2 under IMPULSE READOUT column. Read step 2.1 under TEST STEP/TEST SCOPE column. Component being tested is fuel rack position sensor (L7). Under TEST CONNECTION column, using DVOM, measure resistance between fuel rack position sensor (L7) terminals No. 2 and 3. Under TEST CONDITION column, make measurement with ignition off and fuel rack position sensor connector disconnected. Resistance is 46-54 ohms under NOMINAL VALUE column. If resistance is not within specification, follow instructions under POSSIBLE CAUSE/REMEDY column.

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.

Safety Warning

Understanding Diagnostic Information: Notes

Use the Manual With the Right Hardware

When to See a Mechanic