Water short circuited cable harness and potentiometer noise test


Tools needed:
Wave generator (Saw tooth), Oscilloscope to pickup signal.

Set wave generator to about 2000Hz (Saw tooth), then apply to oscilloscope (set, trim scope), connect wave generator to faulty line, connect oscilloscope test lead to a wet piece of cloth (Resistance), place wet cloth on chassis, body or fender to pickup the signal. Don't short directly to ground, signal will disappear.

Potentiometer test:
Connect an extra resistor in series (R10K) as illustrated. Turn potentiometer slowly, watch oscilloscope for sudden changes.

Central lock rear left door not locking.


Symptom: Door not locking, no noise, no vibrations.
If no specific manufacture software (this not OBDII) at hand, Check door switch function, remove door panel, go directly to cable harness, find wires, close door lock shutter mechanism, bridge BY (blue yellow)- BO (Blue-orange), try central locking system again, if system works properly replace central lock. Check, that cable BY (blue yellow) has ground.

Passenger door mirror mal funktion.


Fallout of the passenger door side mirror, no inward move possible. Removed driver door panelling, freed switch pack, used contact spray, cleaned cable connections to door switch pack, driver control module. Used cheap pair of headphones (max. input voltage about 1.7V) to check for an out coming (S+, S- data line) signal (noise) from the driver door control module to general electronic control module, whilst pressing switch pack switch, rattle connectors, cable harness (though, first turn headphone volume to minimum, to test audio level!). Expected signal (noise) output 2-1600Hz, voltage (around 10V) reduction would be necessary, through the use of a resistor.

General Service Information

General Service Information

Rear axle

Rear sub-frame

Front axle

Lower ball-point joint, Shock absorber bushes, Stabilizer bar links + mounts

Brake disc and pads.htm


Intake Manifold / Ignition Coils / Spark-plugs/ engine-block ventilation (elbow)


Starter system

Valve clearance, timing-chain, tensioner and glides:
With valve clearance in its tolerance, there was no need to take the camshafts down, so tensioners and co. have to wait, the good thing is the tensioner pumps up in 3-4 min. the rattle noise disappears.

Cruise control malfunction, emergency mode

Automatic Transmission 5R55N

Info, tips, Fail Safe Mode

Stall Speed Test procedure and diagnoses

Valve Body, known issues

Valve Body, Solenoid test procedures

Line Pressure Test

Self made press for pressing down clutch drum springs, checking clutch tolerance without a dial gauge


Air Conditioning

Miscellaneous repairs

Wind-shield-wiper mechanism:
Time on the lot took its toll, wind-shield-wiper shafts had seized, uninstalled the mechanism, freed the seized shafts through the use of a good rust loosener, heat, force.

Water in Spark-plug wells 3-2 cylinder:
After days of heavy rain the engine began to misfire with accounted trouble codes, spark-plug wells were wet, an ionized rusty red path on the ceramic insulator had developed which shorted the HV ignition spark.

Connected the radio controls to the multi-functional steering wheel using an analog digital converter.