Multiplex Control System: Diagnosis Honda Element YH2 рестайлинг 2

Sleep and Wake-up Mode Test

1. Shift to the sleep mode: Turn the ignition switch OFF, and remove the key. If the control unit receives no signals from the inputs listed, it will go into sleep mode in less than 40 seconds. INPUTS LIST Multiplex Control Unit No. 10 (7.5 A) under-dash fuse Headlight switch (parking lights position OFF) Driver's door switch (door closed) Passenger's door switches (doors closed) Hatch latch switch (hatch closed) Tailgate latch switch (tailgate closed)
2. Confirm the sleep mode: Measure voltage on the YEL or WHT/GRN wires. There should be battery voltage in the sleep mode. Check the parasitic draw at the battery while shifting into the sleep mode. Amperage should change from about 200 mA to less than 35 mA.
3. Shift to the wake up mode: When the ignition switch is turned ON (II), the multiplex control unit, gauge control module, and ECM/PCM wake up at the same time without "talking" to each other through the communication lines. When any switch in the multiplex system is turned on, it wakes up its related control unit which, in turn, wakes up the other units. After confirming the sleep mode, look in the following table for the switch most closely related to the problem. Operate that switch and see if its control unit wakes up. NOTE: If any control unit is faulty and will not wake up, several circuits in the system will malfunction at the same time. In the table, the control unit is followed by a list of the switches and input signals that can wake it up. LIST OF SWITCHES AND INPUT SIGNALS Multiplex Control Unit No. 10 (7.5 A) under-dash fuse Communication lines (ECM/PCM, keyless receiver unit, and gauge control module) Headlight switch (parking lights position ON) Driver's door switch (door open) Ignition key cylinder switch (key inserted or removed) Ignition switch (ON (II) position)

Multiplex Control Unit Input Test

Note. Before continuing with the multiplex control unit input test, do the multiplex troubleshooting (see TROUBLESHOOTING ).

Scheme 4

1. Remove the driver's dashboard lower cover (see «DRIVER'S DASHBOARD LOWER COVER REMOVAL/INSTALLATION»(ref-290806-S07762317602008072200000) ).
2. Disconnect the under-dash fuse/relay box connectors C, D, F, J, K, O, P, Q, R, X and Y. NOTE: All connectors are shown from wire side of female terminals.
3. 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 .
4. 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. PROBLEM SYMPTOMS TABLE Cavity Wire Test condition Test: Desired result Possible cause if desired result is not obtained J4 BLK Under all conditions Measure voltage to ground: There should be less than 0.5 V. Poor ground (G401) An open in the wire Y6 BLK Under all conditions Measure voltage to ground: There should be less than 0.5 V. Poor ground (G502) An open in the wire J2 WHT/RED Under all conditions Measure voltage to ground: There should be battery voltage. Blown No. 9 (10 A) fuse in the under-hood fuse/relay box An open in the wire Q3 GRN Driver's or left rear door open Measure voltage to ground: There should be less than 0.5 V. Faulty driver's or left rear door switch An open in the wire Driver's and left rear door closed Measure voltage to ground: There should be battery voltage. Faulty driver's or left rear door switch Short to ground in the wire Q4 GRY/BLK Front passenger's or right rear door open Measure voltage to ground: There should be less than 0.5 V. Faulty front passenger's or right rear door switch An open in the wire Front passenger's and right rear door closed Measure voltage to ground: There should be battery voltage. Faulty front passenger's or right rear door switch Short to ground in the wire Q8 GRN/ORN Parking brake lever pulled Measure voltage to ground: There should be less than 0.5 V. Faulty parking brake switch An open in the wire Parking brake lever released Measure voltage to ground: There should be battery voltage. Faulty parking brake switch Short to ground in the wire An open in the wire Q5 BLU/RED Ignition switch ON (II), driver's seat belt is unbuckled. Measure voltage to ground: There should be less than 0.5 V. Faulty driver's seat belt buckle switch Poor ground (G552) An open in the wire Ignition switch ON (II), driver's seat belt is buckled. Measure voltage to ground: There should be battery voltage. Faulty driver's seat belt buckle switch Short to ground in the wire P18 RED Hatch or tailgate open Measure voltage to ground: There should be less than 0.5 V. Faulty hatch latch or tailgate latch switch An open in the wire Hatch and tailgate closed Measure voltage to ground: There should be battery voltage. Faulty hatch latch or tailgate latch switch Short to ground in the wire R4 (A/T) YEL/BLU Shift lever in P position Measure voltage to ground: There should be less than 0.5 V. Faulty park pin switch Poor ground (G401) An open in the wire Shift lever in other than P position Measure voltage to ground: There should be battery voltage. Faulty park pin switch Short to ground in the wire X5 RED/WHT Ignition key is in the ignition switch. Measure voltage to ground: There should be less than 0.5 V. Faulty ignition key switch Poor ground (G401) An open in the wire Ignition key is out of the ignition switch. Measure voltage to ground: There should be battery voltage. Faulty ignition key switch Short to ground in the wire X8 WHT/BLK With all doors closed Attach to ground: The ignition key light should come on. Blown No. 3 (7.5 A) fuse in the under-hood fuse/relay box Faulty ignition key light (LED) An open in the wire O7 GRN/RED Front ceiling light switch in the middle [door] position, all doors closed Attach to ground: The front ceiling light should come on. Blown No. 3 (7.5 A) fuse in the under-hood fuse/relay box Faulty front 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) fuse in the under-hood fuse/relay box Faulty taillight relay An open in the wire K2 BLU/ORN Disconnect under-dash fuse/relay box connector K(17P) and keyless receiver unit 5P connector Check for continuity between the K2 terminal and the keyless receiver unit 5P connector No. 2 terminal: There should be continuity. An open in the wire Check for continuity between the K2 terminal and the keyless receiver unit 5P connector No. 2 terminal: There should be no continuity. Short to ground in the wire K10 WHT/GRN Disconnect under-dash fuse/relay box connector K (17P) and gauge control module 36P connector Check for continuity between the K10 terminal and the gauge control module 36P connector No. 27 terminal: There should be continuity. An open in the wire Check for continuity to ground: There should be no continuity. Short to ground in the wire D10 (A/T) BLK/BLU Shift lever in P position Measure voltage to ground: There should be less than 0.5 V. Poor ground (G101) Faulty transmission range switch An open in the wire Shift lever in other than P position Measure voltage to ground: There should be battery voltage. Short to ground in the wire An open in the wire F9 BLU/WHT Ignition switch ON (II), A/C switch OFF. Measure voltage to ground: There should be battery voltage. Faulty under-dash fuse/relay box Short to ground in the wire Ignition switch ON (II), A/C switch ON. Measure voltage to ground: There should be less than 0.5 V. Faulty heater control panel Faulty A/C pressure switch An open in the wire F1 (1) F8 (1) GRN/ORN Disconnect under-dash fuse/relay box connector F(12P) Check for continuity between the F1 and F8 terminals: There should be continuity. An open in the wire Check for continuity to ground: There should be no continuity. Short to ground in the wire F8 (2) GRN/RED Disconnect under-dash fuse/relay box connector F(12P) and daytime running lights control unit 14P connector Check for continuity between the F8 terminal and daytime running lights control unit 14P connector No. 13 terminal: There should be continuity. An open in the wire Check for continuity to ground: There should be no continuity. Short to ground in the wire F1 (2) GRN/ORN Disconnect under-dash fuse/relay box connector F(12P) and daytime running lights control unit 14P connector Check for continuity between the F1 terminal and daytime running lights control unit 14P connector No. 6 terminal: There should be continuity. An open in the wire Check for continuity to ground: There should be no continuity. Short to ground in the wire (1) '07-08 USA models (2) '07-08 Canada models [ ]: '09 model with overhead console