Safety Warning
DIY auto repair can cause serious injury, fire, or vehicle damage. These guides are for informational purposes only. Always follow OEM torque specs, wear PPE, and consult a certified mechanic if you are unsure. You are solely responsible for your safety.
EDL With Suction-Regulated Control - Changes To OBD (GROUP 01, NO. 96-05)
Reference number: GROUP 01, NO. 96-05
EDL WITH SUCTION-REGULATED CONTROL - CHANGES TO OBD
TECHNICAL SERVICE BULLETIN
EDL WITH SUCTION-REGULATED CONTROL, CHANGES TO OBD
Model(s): 1996-on Audi A4 Quattro
Group: 01 - On-Board Diagnostic
Bulletin No.: 96-05
Date: September 30, 1996
SERVICE INFORMATION
This Bulletin includes new or revised information which will be integrated into the Repair Manual a the next update.
All references to existing Repair Manual pages are for Repair Manual No. W42 014 195 107, "Audi A4 - Suspension, Wheels, Brakes, Steering".
ELECTRONIC DIFFERENTIAL LOCK (EDL) WITH SUCTION-REGULATED CONTROL (VEHICLES WITH ALL WHEEL DRIVE)
EDL with suction-regulated control has been introduced on models with All Wheel Drive beginning with 06.96 production. The pressure increase that takes place in the brake system during an EDL control cycle is no longer regulated on the pressure side of the ABS return flow pump but on its suction side. This method reduces the operating noise during an EDL control cycle.
The following are revisions associated with the change to a suction-regulated system:
- Pressure dampers in the hydraulic unit discontinued (previously used for noise suppression).
- Operating range of the pressure limiting valve in the hydraulic unit increased from 90 +/- 25 bar to 170 +/- 25 bar (1305 +/- 363 psi to 2465 +/- 363 psi).
- Installation of the control module made fail-safe by assigning specific speed sensor inputs.
- Changes to test steps 7, 8, 17 and 18 in the Electrical Test section.
Switch on measuring range: Resistance measurement 2 kohm and 20 kohm
NO RELATED
Use the Manual With the Right Hardware
Pair factory procedures with proven DIY tools so the instructions are easier to execute.
Affiliate disclosure: We may earn a commission at no extra cost to you.
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.