Workshop Hints: Diagnosis
Diagnosis is carried out using Test Modules in the Diagnosis Program as well as on-screen in the Service mode. The Sensor Check display is intended to be used while test driving the vehicle. The following pages contain charts with explanations of the Service Mode display.
TOOL SPECIFICATION
| STATUS DISPLAY | WHAT SHOULD BE DISPLAYED | WHAT TO DO IF NOT OK |
|---|---|---|
| Wheel Sensors: | As the vehicle is driven, the number should increase with an increase in vehicle speed. | Check fault codes in DSC system. If necessay carry out wheel speed sensor test. |
| GPS Satellites: | With unobstructed upward view of sky the display should be >3 | Check for interference of signals to GPS antenna, Check integrity of circuit from GPS antenna to nav computer. |
| GPS Status: | See LOW VOLTAGE table. | |
| Gyro: | Direction icon moves with vehicle turning movement. Milli voltage display value should be approx 2500 mV (+/- 400mV) when the vehicle is stationary or driven straight ahead. When the vehicle is turning, the signal voltage should increase on right hand turns and decrease on left hand turns. |
Replace Navigation computer. |
| Direction: | Reverse is displayed when range selector is in revrse. Forward in any other range. | Check back up light signal input. |
LOW VOLTAGE
| GPS Status Text Display | Description |
|---|---|
| 1. "GPS fault" | Problem with GPS system. Swap nav computer and or antenna from know good vehicle after checking GPS status display information |
| 2. "Reception Interference" | Problem with GPS system. Same as above. |
| 3. "No Almanac" | No Data yet stored from satellites. The GPS almanac is a memory account of received satellite signals. If the vehicle battery has been disconnected or after replacing a nav computer it has an empty memory and requires satellite signals to become functional. After the nav computer receives battery voltage and ground, it must be left outside with an unobstructed sky above with the ignition switched to KL R for approximately 15 minutes. |
| 4. "Satellite search" | GPS is currently searching for satellite signals. |
| 5. "Satellite contact" | At least one satellite is found |
| 6. "Position known" | Vehicle's Latitude and Longitude known. Navigation is possible. |
LATITUDE AND LONGITUDE
| Menu | Display | Explanation |
|---|---|---|
| GPS/Status | G-speed Heading Rec status Pos-src PDOP HDOP VDOP |
Relative speed over the ground Direction of travel Search/track/position receiver status Number of satellites available for analysis Accuracy of the calculated location <8=sufficient determinations of location <4=very good determinations of location |
| GPS/Tracking info | CH PRN S/N Visible Sat Almanac |
Channel Satellite detection Better reception as the value increases Number of visible satellites, receivable Signals, depending on time of day/configuration Satellite database, loaded automatically after 15 minutes |
| Telematics | VIN Color GSM BMW info Emergency call out Initialization Logging off |
VIN (Automatically assigned during coding) Color code or text Telephone network/contract number Customer specific info On/off status Telematics services on/off status Logging off telematics services |
LOGGING OFF
| PDOP | Position Dilution of Precision |
|---|---|
| HDOP | Horizontal Dilution of Precision |
| VDOP | Vertical Dilution of Precision |
| S/N | Signal/noise relationship |
| Gyro | Piezo gyro sensor (in navigation computer) |
| Dir | Direction of travel |