Measurement Of Closed-Circuit Current: Testing
Select a measuring range which ensures that the pointer of the instrument is in the upper third of the scale, as far as possible. Switch over measuring range without interruption. Read off the measuring values after the waiting period specified in the table.
Do not switch on any electrical loads when measuring.
Information
- If the value of the closed-circuit current is higher than the value determined in the table, the cause must be established systematically.
- Recommended troubleshooting procedure: With the measuring device connected, remove the fuses of terminal 30 and the relays successively. Observe the display values of the measuring instrument when removing in order to recognise a reduction in current.
- After troubleshooting, screw the ground strap back onto the body in the proper manner.
- The measured values could vary by approx. 20%.
- The values listed in the table depend on the condition of the battery, the room temperature and the engine temperature.
Reading off the measuring range:
Read off the measuring range only when at least 60 minutes have passed since the start of the measurement.
| From | to | mA |
|---|---|---|
| Approx. 60 min | until battery is empty | up to approx. 20 |
| Control unit | Equipment | Closed-circuit current in mA | System reaches closed-circuit current after X sec |
|---|---|---|---|
| Generator | Standard | 0.3 | instantaneous |
| DME | Standard | 0.31 | 66 |
| Instrument cluster | Standard | 1.75 | 958 |
| Driver ID/PAS | Standard | 0.8 | 223 |
| Passenger compartment sensor | I No. | 1.93 | 60 |
| Tilt sensor | I No. | 1.15 | instantaneous |
| Door control unit, right | Standard | 0.1 | 221 |
| Door control unit, left | Standard | 0.1 | 221 |
| Tiptronic* | I No. | 0.4 | |
| On-board control unit | Standard | 0.41 | 226 |
| PSM | Standard | 0.1 | 61 |
| Front end control unit | Standard | 0.52 | 226 |
| CD changer | I No. | 0.25 | 80 |
| Bose amplifier | I No. | 0.47 | 226 |
| Navi DVD | I No. | 3.18 | 117 |
| ASK sound package I | No. | 0.1 | |
| PCM | I No. | 0.59 | 308 |
| Telephone | I No. | 0.15 | 104 |
| Seat memory, both | I No. | 0.15 | 221 |
| Air-conditioning control unit | Standard | 0.1 | 3506 |
| Ignition lock | Standard | 0.1 | instantaneous |
| Gateway control unit | Standard | 0.1 | 308 |
| Rear control unit | Standard | 1.27 | 222 |
| Steering column module | Standard | 0.71 | 221 |
| Fan control unit | Standard | 0.1 | instantaneous |
| PASM | I No. | 0.1 | 62 |
| TPM (Tire Pressure Monitoring) | I No. | 0.12 | 221 |
| Sport Chrono | I No. | 0.1 | 308 |
| Alarm siren | I No. | 0.2 | |
| Total current | calculated | 15.66 | |
| Total current | max. | 20 | after 60 minutes |