Multiplex Control Unit Input Test
- Remove the driver's dashboard lower cover (see DRIVER'S DASHBOARD LOWER COVER REMOVAL/INSTALLATION ).
- Disconnect the under-dash fuse/relay box connectors C, E, F, J, K, 0, P, Q, X and Y.NOTE: All connectors are wire side of female terminals.
- 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 look OK, go to step 4.
- With the connectors still disconnected, 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 5.CAVITY TEST CONDITION SPECIFICATION
Cavity Wire Test condition Test: Desired result Possible cause if result is not obtained J4 BLK Under all conditions Check for continuity to ground:
There should be continuity.- Poor ground (G301)
- An open in the wire
Y6 BLK Under all conditions Check for continuity to ground:
There should be continuity.- Poor ground (G401)
- An open in the wire
Y1 BLK Under all conditions Check for continuity to ground:
There should be continuity.- Poor ground (G401)
- An open in the wire
- Reconnect the connectors to the under-dash fuse/relay box, and make these input tests at the appropriate connectors on the under-dash fuse/relay box.
- If any test indicates a problem, find and correct the cause, then recheck the system.
- If all the input tests prove OK, the multiplex control unit must be faulty, replace the under-dash fuse/relay box assembly.CAVITY TEST CONDITION SPECIFICATION
Cavity Wire Test condition Test: Desired result Possible cause if result is not obtained J2 WHT/RED Under all conditions Check for voltage to ground:
There should be battery voltage.- Blown No. 9 (7.5 A) fuse in the underhood fuse/relay box
- An open in the wire
Q3 GRN Driver's door open Check for voltage to ground:
There should be 1 V or less.- Faulty driver's door switch
- An open in the wire
Driver's door closed Check for voltage to ground:
There should be 5 V or more.- Faulty driver's door switch
- Short to ground
Q4 LT GRN/RED Passenger's door open Check for voltage to ground:
There should be 1 V or less.- Faulty passenger's door switch
- An open in the wire
Passenger's door closed Check for voltage to ground:
There should be 5 V or more.- Faulty passenger's door switch
- Short to ground
Q8
C8
F1GRN/ORN
GRN/ORN
GRN/REDParking brake lever up Check for voltage to ground:
There should be 1 V or less.- Faulty parking brake switch
- An open in the wire
Parking brake lever down Check for voltage to ground:
There should be 5 V or more.- Faulty parking brake switch
- Short to ground
Q5 BLU/RED Ignition switch ON (II) driver's seat belt is unbuckled. Check for voltage to ground:
There should be 1 V or less.- Faulty driver's seat belt switch
- Poor ground (G551)
- An open in the wire
Q6 BLU/RED Ignition switch ON (II) driver's seat belt is buckled. Check for voltage to ground:
There should be 5 V or more.- Faulty driver's seat belt switch
- Short to ground
P18 RED Hatch open Check for voltage to ground:
There should be 1 V or less.- Faulty hatch latch switch
- Poor ground (G701)
- An open in the wire
Hatch closed Check for voltage to ground:
There should be 5 V or more.- Faulty hatch latch switch
- Short to ground
X5 RED/WHT Ignition key is in the ignition switch Check for voltage to ground:
There should be 1 V or less.- Faulty ignition key switch
- Poor ground (G401)
- An open in the wire
Ignition key is out of the ignition switch Check for voltage to ground:
There should be 5 V or more.- Faulty ignition key switch
- Short to ground
X8 WHT/BLK Under all conditions Attach to ground:
The ignition key light should come on.- Blown No. 3 (7.5 A) fuse in the underhood fuse/relay box
- Blown LED
- An open in the wire
O7 GRN/RED Ceiling light switch in the middle position, all doors closed Attach to ground:
The ceiling light should come on.- Blown No. 3 (7.5 A) fuse in the underhood fuse/relay box
- Faulty ceiling light
- An open in the wire
C11 BLU Under all conditions Attach to ground:
Dash lights should come on.- Blown No. 2 (15 A) [No. 2 (10 A)] fuse in the underhood fuse/relay box
- Faulty taillight relay
- An open in the wire
F8 GRN/RED Brake fluid reservoir float in down position (brake fluid removed) Check for voltage to ground:
There should be less than 1 V.- Faulty brake fluid level switch
- An open in the wire
Brake fluid reservoir float in up position (brake fluid at full level) Check for voltage to ground:
There should be 5 V or more.- Faulty brake fluid level switch
- Short to ground
E10 YEL Under all conditions Check for voltage to ground:
There should be battery voltage in the sleep mode and 3-7 V when awake.An open or short in the wire K10 WHT/GRN Under all conditions Check for voltage to ground:
There should be battery voltage in the sleep mode and 3-7 V when awake.An open or short in the wire [ ]: '05-06 models