The customer booked this car because she said the engine cuts out and she has to stop and wait for a minute or two, she will restart it but then the ESP light is on and the steering is hard to turn. I first check all battery cables, they are looking ok. I took the car for a test drive and it happen exactly as the lady explained. I got back to the workshop and plug in the scanner and I found the following faults:
ECM(Engine Control
Module)-Leaded All
( 1 )
Abnormal
P0339 Crankshaft Position (CKP) Sensor Circuit-Malfunction
ECM(Engine Control
Module)-Unleaded EOBD
( 1 )
Abnormal
P0339 Crankshaft Position (CKP) Sensor Circuit-Malfunction
ECM(Engine Control
Module)-Unleaded GEN
( 1 )
Abnormal
P0339 Crankshaft Position (CKP) Sensor Circuit-Malfunction
ESP (Electronic Stability
Program)
( 1 )
Abnormal
C1213 Wheel Speed Frequency Error
History
SRS (Supplemental
Inflatable Restraint
System)
( 1 )
Abnormal
B1102 Battery Voltage Low
Present
EPS (Electronic Power
Steering)
( 1 )
Abnormal
C1617 EMS Invalid Engine Speed
Present
For the low battery voltage, I have fitted an extra thick earth cable from the battery negative terminal to the gearbox. I don’t like the strap type which is fitted from the chassis to the gearbox. The C1617 fault is related to the crank sensor fault. The ESP is also affected by the crank sensor, you might think it is a different problem but not so.
The next thing I did is to connect the Picoscope, I want to see how the crank sensor is performing. I connect the Picoscope and while it is idling the waveform looks great, but when I rev it to about 3000rpm the waveform change to the image below. Now you can clearly see there is a problem with the performance of the sensor. Between the beginning and end of each cycle (teeth on the flywheel) the sensor dropout. See the image below.
The waveform should look like the image below.
After I have fitted the new sensor I have checked the waveform of the new sensor to make sure it operates properly. The image above show the results. Now you could have just replaced the crank sensor and the car would have been fixed. But I like to make sure the crank sensor is at fault. After the new sensor is fitted the engine does not cut out anymore and ESP does not give problems by becoming stiff to turn. Hope this will help you.