Front Left Wheel Sensor Dtc 21 - Porsche 928 Workshop Manual

39
Differential, transaxle system 928
Fault, DTC
Possible causes, remedy, notes
Test
point
6
Fmnt
lefl
wheel sensor
DTC 21
No signal from speed sensor reaches control unit, or signal is incorrect
I unrealistic.
Important:
This fault is also indicated if the PDAWABS control unit for
the 911 Carrera 4 (964) is installed.
If assembly work has already taken place, check that the correct con-
trol unit has been installed.
Distinguishing feature: part number,
928 control unit with PSD
= 928 618 .,, __
911 Carrera 4 control unit = 964 618 ,..
/--
1
I. Pull off the control unit plug. Measure the internal resistance I
check continuity between PIN 50 and PIN 48 on the
plug.
Nominal value 600...1600 R.
If the nominal value is not attained, check the wires and plug con-
nections in the circuit from the front left speed sensor.
If the nominal value (600...1600 n) is not attained although the
wires I plug connections are in working order, replace the speed
sensor.
Important:
Perform measurement directly on the speed sensor be-
fore replacing the sensor.
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D39 - 236
a
PSD diagnosis/Troubleshooting
Prtntsd in Gcmny - XXXV. ISM