Wipers/Washers (Multiplex Control Unit) Input Test

1.Before testing, troubleshoot the multiplex control system.

2.Remove the dashboard lower cover.

3.Disconnect the under-dash fuse/relay box connectors B, F, G, J, X and Y.

NOTE: All connectors are wire side of female terminals.

 

4.Inspect the connector and socket terminals to be sure they are all making good contact.

  • If the terminals are bent, loose or corroded, repair them as necessary, and recheck the system.
  • If the terminals are OK, go to 5.

5.Reconnect the connectors, and make these input tests at the connector.

  • If any test indicates a problem, find and correct the cause, then recheck the system.
  • If all the input tests prove OK, go to step 6.
  • If all the input tests prove OK, the multiplex control unit must be faulty; replace the under-dash fuse/relay box assembly.

Cavity Wire Test condition Test: Desired result Possible cause if result is not obtained 
J4 BLK Under all conditions Check for voltage to ground:
There should be 1 V or less. 
  • Poor ground (G301)
  • An open in the wire
 
Y6 BLK Under all conditions Check for voltage to ground:
There should be 1 V or less. 
  • Poor ground (G502)
  • An open in the wire
 
B1
·
F6 
WHT/BLU Ignition switch ON (II) and washer switch ON Check for voltage to ground:
There should be battery voltage.
Check windshield washer motor operation:
The washer motor should run. 
  • Poor ground (G301)
  • Blown No. 20 (20 A) fuse in the under-dash fuse/relay box
  • Faulty wiper/washer switch
  • Faulty windshield washer motor
  • An open in the wire
 
B6 BLU/RED Ignition switch ON (II), wiper switch in OFF or INT, jump B6 to ground. Check for voltage to ground:
There should be battery voltage.
Check wiper motor operation:
The wiper motor should run at low speed. 
  • Blown No. 20 (20 A) fuse in the under-dash fuse/relay box
  • Faulty wiper/washer switch
  • Faulty windshield wiper motor
  • An open in the wire
 
G7 BLU/WHT Ignition switch ON (II) and wipers in park position. Check for voltage to ground:
There should be battery voltage. 
  • Blown No. 20 (20 A) fuse in the under-dash fuse/relay box
  • Faulty windshield wiper motor
  • An open in the wire
 
X7 BLU/BLK Ignition switch ON (II) and wiper switch in INT Check for voltage to ground:
There should be battery voltage. 
  • Blown No. 20 (20 A) fuse in the under-dash fuse/relay box
  • Faulty wiper/washer switch
  • An open in the wire