P1300,P1301
Symptom: Poorer shifting performance
Torque limitation, signal low or too long
Fault symptom
Poorer shifting performance
Condition
Signal low (0 V) for longer than two seconds
or
PWM
signal active for longer than 2.5 seconds more than three times within
30 seconds.
1.
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The signal from the AF22
control module to the MOTRONIC control
module, which is a request for torque limitation, is extremely short
(about 250 ms) and may therefore be difficult to check.
Connect the ISAT to the AF22 control module. Select
"TORQUE LIMITATION" in the "ACTIVATE" menu. When activated,
"TORQUE LIMITATION" sends a signal to the MOTRONIC control module.
At engine speeds above 3000 rpm the MOTRONIC system will then retard
the ignition briefly as "ordered" by the AF22 control module. If
the torque reduction function works, it can easily be heard by the
change in the engine note.
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2.
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If no indication of torque limitation can be heard as described
above, check the lead between pin 51 of the MOTRONIC control module and
pin 13 of the AF22 control module for shorting to ground.
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3.
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If the cause of the fault does not come to light after carrying out the
above diagnostic procedure, and no trouble codes are generated in the
AF22 system, clear any trouble codes in the MOTRONIC system and drive
the car on the road to check whether the codes are generated afresh. If
they are, turn to
for further diagnostic instructions.
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