90CS Quattro V6-2.8L (AAH) (1994)
- unplug both infrared sensors
- disconnect central locking pump from VAG 1598/11
-
using multimeter Fluke 83 (US 1119), set to Ohm range, check continuity from terminal 15 to Ground (GND) for right sensor
^ must be Infinity Ohms
-
check continuity from terminal 16 to GND for left sensor
^ must be Infinity Ohms
If continuity is not found, and voltage at terminals 15 and 16 do not return to specified voltage with both sensors unplugged:
-
replace central locking pump
If voltage returns to specified voltage when one sensor is unplugged:
-
replace that sensor
C
If specified voltage too low:
-
remove B-pillar trim from low voltage side
-
unplug infrared sensor
-
disconnect central locking pump from VAG 1598/11
-
using multimeter Fluke 83 (US 1119), set to Ohm range, check continuity from terminal 2 to Ground (GND) if the right side is too low
^ must be Infinity Ohms
-
check continuity from terminal 10 and GND if the left side is too low
^ must be Infinity Ohms
If continuity is not found on low voltage side:
-
replace infrared sensor on low voltage side
D
If voltage does not decrease specified amount:
-
remove B-pillar trim from side that does not decrease
-
unplug infrared sensor
-
using multimeter Fluke 83 (US 1119), set to Ohm range, check the infrared sensor Ground (GND) wire in vehicle harness for continuity to GND
^ must be 0 Ohm
If OK:
-
leave infrared sensor unplugged
-
disconnect central locking pump from VAG 1598/11
-
using wiring diagram and multimeter, check continuity of power and signal wires between the infrared sensor and central locking pump
^
terminal 16 and the infrared sensor and terminal 10 and the infrared sensor if left side does not decrease
^
terminal 15 and the infrared sensor and terminal 2 and the infrared sensor if the right side does not decrease