Battery/starter (Current Measurement)
| Measurement: | Plot of the starter current during the start procedure. |
|---|---|
| Check Objective: | Evaluation of the battery charge and the current supply to the battery as well as the operation of the starter. |
Preparation
Zero current probe using multimeter test (see section 2.5). Do not thereafter alter the knurled zero adjustment knob. Engine oil temperature > 20 �C.
Switch off the engine, switch off the ignition, switch off all electrical loads.
Connections
| INPUT A | COM/TRIGGER |
|---|---|
| Clamp the current measurement probe across all of the positive or negative leads on the battery. The plus sign on the current indicator must point towards the positive pole. Select the 1 mV/A measurement range. |
Procedure
Start engine.
Reference Curve
Fault Scheme 1
Symptoms:
Maximum < 800 A
Signal end < 0 A
| Possible Causes | Countermeasures |
|---|---|
| Poor contact | Check supply leads and connections on battery and starter. |
| Faulty starter | Check starter and repair if necessary. |
Note
A current spike in the last third of the measurement curve can be traced to the activation of the air pump on vehicles with secondary air injection (X-engines) and a cold engine.
This does not represent a fault!