Diagnostics

GEAR SELECTION CHART:

The Electrical Troubleshoooting Manual update for the E34 has the following information on this system:

- Pin assignments
- Troubleshooting
- Component testing
- Defect codes

When diagnosing this system, along with knowing what isni working, it is important to also know what is working correctly. For example, a simple pressure check while the throttle pressure regulator is activated at both high and low current (easily done with BMW Service Tester) can quickly verify the function of several components; oil supply circuit, pump, feed limit valve, throttle pressure solenoid, line boost valve, and main pressure regulator valve. By checking whole subsystems before zeroing in on individual components, the time spent troubleshooting will be more productive.