Multiplex Control Systems: Diagnosis Toyota Prius I рестайлинг

Diagnostic System Pre-Check

Note. Diagnostic system pre-check must be performed before retrieving Diagnostic Trouble Codes (DTC) to ensure body Electronic Control Unit (ECU) is working properly so body ECU is able to diagnose the multiplex control system.

Scheme 8

1. To check body ECU operation, check to see if interior light at center of headliner works when switch is in DOOR position and door is opened. If interior light does not operate properly, go to next step. If interior light operates properly, go to step 3.
2. Check operation of interior light. See INTERIOR LIGHT under COMPONENT TESTS in BODY CONTROL SYSTEMS - PRIUS article. If interior light is okay, replace body ECU. See «BODY CONTROL ELECTRONIC CONTROL UNIT»(ref-132865-S07323595182001112800000) under REMOVAL & INSTALLATION. If interior light is defective, replace component as necessary.
3. To check open door indicator light operation, open door and check that open door indicator light turns on. Open door indicator light is located just to the left of speedometer on combination meter. (Scheme 8) Combination meter is located at center of instrument panel. see scheme 2 If open door indicator light operates properly, proceed to retrieving diagnostic trouble codes by using Toyota hand-held tester or open door indicator light. See «USING TOYOTA HAND-HELD TESTER»(ref-132865-S34040423482001112800000) or «USING OPEN DOOR INDICATOR LIGHT»(ref-132865-S04870021642001112800000). If open door indicator light does not operate properly, check combination meter and wiring circuit for open door indicator light. For open door indicator light wiring circuit, see WIRING DIAGRAMS in ILLUMINATION/INTERIOR LIGHTS article.

Scheme 9

Scheme 10

1. Connect Toyota hand-held tester to Data Link Connector (DLC) No. 3. (Scheme 9) Turn ignition on with engine off. Turn hand-held tester on. Using hand-held tester manufacturer's instructions, check for DTCs. Record any existing DTCs.
2. If any DTCs exist, identify DTC and then perform appropriate DTC test under «DIAGNOSTIC TESTS»(ref-132865-S05964834702001112800000). For DTC identification, see «DIAGNOSTIC TROUBLE CODE DEFINITIONS»(ref-132865-S17733444532001112800000) table. NOTE: If Diagnostic Trouble Code (DTC) for loss of communication exists, there is a possibility that a electrical connector is disconnected or 2 communication bus lines are open. (Scheme 10) DTC will not exist if only one communication line is open. (Scheme 10) If 2 communication bus lines are open at specified positions, a DTC for loss of communication for those 2 communication bus lines will exist for the 3 ECUs. (Scheme 10) NOTE: DTCs B1221, B1222 and B1241 are for a switch and circuit test function for related circuits. When system is in DTC retrieval mode, switches must be operated to determine condition of switch and circuit. If switch circuit is operating properly, the relevant DTC will set while switch is being operated. If DTC is not set when switch is operated, an open circuit is present in either switch contacts or wiring circuit. If DTC sets before switch is operated, switch contacts are stuck or wiring circuit is shorted.

CLEARING DIAGNOSTIC TROUBLE CODES

Diagnostic Trouble Codes (DTC) will be erased from memory of body Electronic Control Unit (ECU) when problem causing the DTC has been repaired.

DIAGNOSTIC TESTS

Diagnostic Aids

DTC exists when communication stops between driver's door Electronic Control Unit (ECU) and body ECU for more than 10 seconds. Possible causes are: defective driver's door ECU or wiring harness.

Diagnosis & Repair

1. Turn ignition on. Check operation of auto up function on driver's door power window. Auto up function controls automatic operation of power window. When power window switch is pulled completely upward and then released, the power window will fully close. If driver's door power window auto up function operates properly, go to next step. If driver's door power window auto up function does not operate properly, replace driver's door ECU. See «DRIVER'S DOOR ELECTRONIC CONTROL UNIT»(ref-132865-S19084879272001112800000) under REMOVAL & INSTALLATION.
2. Turn ignition off. Disconnect electrical connector B8 at body ECU. see scheme 3 Body ECU is located at driver's side of instrument panel on the fuse/relay box and uses an 18-pin and 20-pin electrical connector. see scheme 3 Disconnect electrical connector at driver's door ECU. Driver's door ECU is located on driver's door and is incorporated into the power window switch assembly. see scheme 2
3. Using ohmmeter, check for continuity between terminal No. 6 (Yellow wire) at electrical connector B8 for body ECU and terminal No. 18 (Yellow wire) at electrical connector for driver's door ECU. see scheme 3and see scheme 12. If continuity exists, replace driver's door ECU. See «DRIVER'S DOOR ELECTRONIC CONTROL UNIT»(ref-132865-S19084879272001112800000) under REMOVAL & INSTALLATION. If continuity does not, repair wiring harness or electrical connector as necessary.

DTC is for power window switch and circuit. When system is in DTC retrieval mode, power window switch on driver's door must be operated to determine condition of power window switch and circuit. If power window switch is operating properly, DTC will set while power window switch is being operated. If DTC is not set when power window switch is operated, an open circuit exists in the power window switch contacts or wiring circuit. If DTC sets before power window switch is operated, power window switch is defective, as the switch contacts are stuck or short exists in wiring circuit. Power window switch on driver's door also contains the driver's door Electronic Control Unit (ECU).

Operate power window switch on driver's door while checking for DTCs. DTC should exist while operating power window switch to indicate power window switch is okay. If DTC sets before power window switch is operated, power window switch contacts are stuck. If DTC does not exist while operating power window switch, power window switch or wiring circuit may be defective. It may be necessary to replace power window switch and recheck operation. If power window switch still does not operate as specified, it may be necessary to inspect the wiring harness and electrical connectors. See WIRING DIAGRAMS . For additional wiring for power windows, see POWER WINDOWS - CARS article.

DTC is for door lock switch and circuit. When system is in DTC retrieval mode, door lock switch on driver's door must be operated to determine condition of door lock switch and circuit. If door lock switch is operating properly, DTC will set while door lock switch is being operated. If DTC is not set when door lock switch is operated, an open circuit exists in the door lock switch contacts or a problem may exist in the door key lock and unlock switch. If DTC sets before door lock switch is operated, door lock switch is defective, as the switch contacts are stuck. Door lock switch is incorporated into the power window switch assembly on driver's door. Power window switch assembly also contains the driver's door Electronic Control Unit (ECU).

Operate door lock switch on driver's door while checking for DTCs. DTC should exist while operating door lock switch to indicate door lock switch is okay. If DTC sets before door lock switch is operated, door lock switch contacts are stuck. If DTC does not exist while operating door lock switch, door lock switch, door key lock and unlock switch or wiring circuit may be defective. It may be necessary to replace door lock switch and recheck operation. If door lock switch still does not operate as specified, it may be necessary to check door key lock and unlock switch and inspect the wiring harness and electrical connectors. See WIRING DIAGRAMS . For testing of door key lock and unlock switch, see DOOR KEY LOCK & UNLOCK SWITCH under COMPONENT TESTS in BODY CONTROL SYSTEMS - PRIUS article. For additional wiring for door key lock and unlock switch, see WIRING DIAGRAMS in POWER DOOR LOCKS & REMOTE KEYLESS ENTRY SYSTEMS - PRIUS article.

DTC is for stoplight switch and circuit. When system is in DTC retrieval mode, stoplight switch must be operated to determine condition of stoplight switch and circuit. If stoplight switch is operating properly, DTC will set while stoplight switch is being operated. If DTC is not set when stoplight switch is operated, an open circuit exists in the stoplight switch contacts. If DTC sets before stoplight switch is operated, stoplight is defective, as the switch contacts are stuck.

Operate stoplight switch while checking for DTCs. DTC should exist while operating stoplight switch to indicate stoplight switch is okay. If DTC sets before stoplight switch is operated, stoplight switch contacts are stuck. If DTC does not exist while operating stoplight switch, stoplight switch or wiring circuit may be defective. It may be necessary to replace stopligh switch and recheck operation. If stoplight switch still does not operate as specified, it may be necessary to inspect the wiring harness and electrical connectors.

DTC exists when ground exists in RDA signal circuit between body Electronic Control Unit (ECU) and wireless door control receiver. Possible causes are: defective body ECU, defective wireless door control receiver or defective wiring harness. Wireless door control receiver may also be referred to as wireless door lock control receiver or wireless door lock tuner.

Scheme 11

1. Ensure ignition is off. Disconnect electrical connector at wireless door control receiver. Wireless door control receiver is located near center of instrument panel and contains a 5-pin electrical connector. (Scheme 11) Disconnect electrical connector B8 at body ECU. see scheme 3 Body ECU is located at driver's side of instrument panel on the fuse/relay box and uses an 18-pin and 20-pin electrical connector. see scheme 3
2. Using ohmmeter, check for continuity between body ground and terminal No. 8 (Blue wire) at electrical connector B8 for body ECU. For terminal identification on electrical connector B8 for body ECU see scheme 3 If continuity does not exist, go to next step. If continuity exists, repair short to ground on Blue wire between body ECU and wireless door control receiver.
3. Reinstall electrical connector B8 at body ECU. Ensure electrical connector is still disconnected at wireless door control receiver. Recheck for DTCs. If original DTC still exists, replace body ECU. See «BODY CONTROL ELECTRONIC CONTROL UNIT»(ref-132865-S07323595182001112800000) under REMOVAL & INSTALLATION. If original DTC does not exist, replace wireless door control receiver.

DTC exists when communication stops between gateway Electronic Control Unit (ECU) and Audio Visual Communication Local Area Network (AVC-LAN) circuit to multi-display. Possible causes are: defective gateway ECU or defective wiring harness.

Scheme 12

Scheme 13

1. Connection of gateway ECU can be checked by using the AVC-LAN diagnosis service check mode for the audio system or navigation system. Ensure vehicle is stopped and parking brake is applied. Turn ignition switch to ACC position. Press DISPLAY switch to display the screen adjustment screen. Perform STEP 1 in illustration. (Scheme 12) DISPLAY switch is located just above A/C controls and stereo. Screen adjustment screen will be displayed on multi-display located at the center of instrument panel. see scheme 2
2. Repeatedly touch the upper and lower concealed touch switches on the multi-display 3 times. Perform STEP 2 in illustration. (Scheme 12) Service check mode display will be displayed on the multi-display. Note display for the G/W ECU on the service check mode display. Perform STEP 3 in illustration. (Scheme 12)
3. Display for G/W ECU should be one of the following: G/W ECU OK (system is normal), G/W ECU NG (communication error) or G/W ECU None (never registered). If any of these displays exist, go to next step. If any other display than one of these is displayed, turn ignition switch from ACC to OFF position to stop the service check mode. Replace gateway ECU. See «GATEWAY ELECTRONIC CONTROL UNIT»(ref-132865-S26837465272001112800000) under REMOVAL & INSTALLATION.
4. Turn ignition switch from ACC to OFF position to stop the service check mode. Disconnect electrical connector at gateway ECU. Gateway ECU is located behind center of instrument panel and contains a Gray 14-pin electrical connector. see scheme 2 Disconnect electrical connector M5 at multi-display. (Scheme 13)
5. Using ohmmeter, check for continuity between terminal TX3+ (Red wire) at electrical connector M5 for multi-display and terminal GTX+ (Red wire) at gateway ECU electrical connector. (Scheme 13) Also, check for continuity between terminal TX3- (Green wire) at electrical connector M5 for multi-display and terminal GTX- (Green wire) at gateway ECU electrical connector. (Scheme 13) If continuity exists on both circuits, replace gateway ECU. See «GATEWAY ELECTRONIC CONTROL UNIT»(ref-132865-S26837465272001112800000) under REMOVAL & INSTALLATION. If continuity does not exist on any circuit, repair wiring harness or electrical connector as necessary.

DTC exists when communication stops between Engine Control Module (ECM) and body Electronic Control Unit (ECU) for more than 10 seconds. Possible causes are: defective ECM or defective wiring harness.

Scheme 14

1. Check that engine starts normally. If engine starts normally, go to next step. If engine does not start normally, replace ECM. See «ENGINE CONTROL MODULE»(ref-132865-S17331344742001112800000) under REMOVAL & INSTALLATION.
2. Disconnect electrical connector B8 at body ECU. see scheme 3 Body ECU is located at driver's side of instrument panel on the fuse/relay box and uses an 18-pin and 20-pin electrical connector. see scheme 3 Disconnect electrical connector at gateway ECU. Gateway ECU is located behind center of instrument panel and contains a Gray 14-pin electrical connector. see scheme 2 Note location of ECM behind the glove box. see scheme 2 Disconnect electrical connector E10 at ECM. (Scheme 14)
3. Using ohmmeter, check for continuity between terminal MPX- (Gray wire) at electrical connector B8 for body ECU and terminal MPX2 (Gray wire) at electrical connector E10 for ECM. (Scheme 14) Also, check for continuity between terminal MPX1 (Gray/Blue wire) at electrical connector E10 for ECM and terminal MPD2 (Gray/Blue wire) at gateway ECU electrical connector. (Scheme 14) If continuity exists on both circuits, replace ECM. See «ENGINE CONTROL MODULE»(ref-132865-S17331344742001112800000) under REMOVAL & INSTALLATION. If continuity does not exist on any circuit, repair wiring harness or electrical connector as necessary.

DTC exists when communication stops between A/C amplifier and body Electronic Control Unit (ECU) for more than 10 seconds. Possible causes are: defective A/C amplifier or defective wiring harness.

Note. A/C amplifier may also be referred to as air conditioning ECU and combination meter may also be referred to as combination meter Electronic Control Unit (ECU).

Scheme 15

1. Disconnect electrical connector at gateway ECU. Gateway ECU is located behind center of instrument panel and contains a Gray 14-pin electrical connector. see scheme 2 Note location of A/C amplifier behind center of instrument panel. see scheme 2 Disconnect electrical connector A7 at A/C amplifier. (Scheme 15) Note location of combination meter at center of instrument panel. see scheme 2 Disconnect electrical connector C11 at combination meter. (Scheme 15) For combination meter removal procedures, see «COMBINATION METER»(ref-132865-S40724830482001112800000) under REMOVAL & INSTALLATION.
2. Using ohmmeter, check for continuity between terminal MPD1 (Gray/Black wire) at gateway ECU electrical connector and terminal MP2+ (Gray/Black wire) at electrical connector A7 for A/C amplifier. (Scheme 15) Also, check for continuity between terminal MPX+ (Gray wire) at electrical connector A7 for A/C amplifier and terminal MPX- (Gray wire) at electrical connector C11 for combination meter. (Scheme 15) If continuity exists on both circuits, replace A/C amplifier. See «A/C AMPLIFIER»(ref-132865-S18609984152001112800000) under REMOVAL & INSTALLATION. If continuity does not exist on any circuit, repair wiring harness or electrical connector as necessary.

DTC exists when short exists in B+ or GND circuit for instrument panel system communication bus. Possible causes are: defective Engine Control Module (ECM), gateway Electronic Control Unit (ECU), defective A/C amplifier, defective combination meter, defective body ECU or defective wiring harness.

Note. A/C amplifier may also be referred to as air conditioning ECU and combination meter may also be referred to as combination meter ECU.

1. Note location of ECM behind the glove box. see scheme 2 Disconnect electrical connector E10 at ECM. (Scheme 14) Recheck for DTCs. If original DTC still exists, go to next step. If original DTC does not exist, replace ECM. See «ENGINE CONTROL MODULE»(ref-132865-S17331344742001112800000) under REMOVAL & INSTALLATION.
2. Reinstall electrical connector E10 at ECM. Disconnect electrical connector at gateway ECU. Gateway ECU is located behind center of instrument panel and contains a Gray 14-pin electrical connector. see scheme 2 Recheck for DTCs. If original DTC still exists, go to next step. If original DTC does not exist, replace gateway ECU. See «GATEWAY ELECTRONIC CONTROL UNIT»(ref-132865-S26837465272001112800000) under REMOVAL & INSTALLATION.
3. Reinstall electrical connector at gateway ECU. Note location of A/C amplifier behind center of instrument panel. see scheme 2 Disconnect electrical connector A7 at A/C amplifier. (Scheme 15) Recheck for DTCs. If original DTC still exists, go to next step. If original DTC does not exist, replace A/C amplifier. See «A/C AMPLIFIER»(ref-132865-S18609984152001112800000) under REMOVAL & INSTALLATION.
4. Reinstall electrical connector at A/C amplifier. Note location of combination meter at center of instrument panel. see scheme 2 Disconnect electrical connector C11 at combination meter. (Scheme 15) For combination meter removal procedures, see «COMBINATION METER»(ref-132865-S40724830482001112800000) under REMOVAL & INSTALLATION. Recheck for DTCs. If original DTC still exists, go to next step. If original DTC does not exist, replace combination meter.
5. Reinstall electrical connector C11 at combination meter. Disconnect electrical connector B8 at body ECU. see scheme 3 Body ECU is located at driver's side of instrument panel on the fuse/relay box and uses an 18-pin and 20-pin electrical connector. see scheme 3 Recheck for DTCs. If original DTC still exists, go to next step. If original DTC does not exist, repair short in wiring harness and electrical connectors between combination meter and body ECU. See «WIRING DIAGRAMS»(ref-132865-S41344227782001112800000).
6. Reinstall electrical connector B8 at body ECU. Disconnect electrical connector E10 at ECM. (Scheme 14) Recheck for DTCs. If original DTC still exists, go to next step. If original DTC does not exist, repair short in wiring harness and electrical connectors between body ECU and ECM. See «WIRING DIAGRAMS»(ref-132865-S41344227782001112800000).
7. Reinstall electrical connector E10 at ECM. Disconnect electrical connector at gateway ECU. Recheck for DTCs. If original DTC still exists, go to next step. If original DTC does not exist, repair short in wiring harness and electrical connectors between ECM and gateway ECU. See «WIRING DIAGRAMS»(ref-132865-S41344227782001112800000).
8. Reinstall electrical connector gateway ECU. Disconnect electrical connector A7 at A/C amplifier. (Scheme 15) Recheck for DTCs. If original DTC still exists, go to next step. If original DTC does not exist, repair short in wiring harness and electrical connectors between gateway ECU and A/C amplifier. See «WIRING DIAGRAMS»(ref-132865-S41344227782001112800000).
9. Reinstall electrical connector A7 at A/C amplifier. Disconnect electrical connector C11 at combination meter. (Scheme 15) Recheck for DTCs. If original DTC still exists, replace body ECU. See «BODY CONTROL ELECTRONIC CONTROL UNIT»(ref-132865-S07323595182001112800000) under REMOVAL & INSTALLATION. If original DTC does not exist, repair short in wiring harness and electrical connectors between A/C amplifier and combination meter. See «WIRING DIAGRAMS»(ref-132865-S41344227782001112800000).

DTC exists when communication stops between combination meter Electronic Control Unit (ECU) in combination meter and body ECU for more than 10 seconds. Possible causes are: defective combination meter or defective wiring harness.

Note. Combination meter ECU may also be referred to as combination meter.

Scheme 16

1. Check speedometer and tachometer operation to verify operation of combination meter ECU. If speedometer and tachometer operate properly, go to next step. If speedometer and tachometer do not operate properly, combination meter ECU is defective. Replace combination meter. See «COMBINATION METER»(ref-132865-S40724830482001112800000) under REMOVAL & INSTALLATION.
2. Note location of A/C amplifier behind center of instrument panel. see scheme 2 Disconnect electrical connector A7 at A/C amplifier. (Scheme 16) Note location of combination meter at center of instrument panel. see scheme 2 Disconnect electrical connector C11 at combination meter. (Scheme 16) For combination meter removal procedures, see «COMBINATION METER»(ref-132865-S40724830482001112800000) under REMOVAL & INSTALLATION. Disconnect electrical connector B8 at body ECU. see scheme 3 Body ECU is located at driver's side of instrument panel on the fuse/relay box and uses an 18-pin and 20-pin electrical connector. see scheme 3
3. Using ohmmeter, check for continuity between terminal MPX- (Gray wire) at electrical connector C11 for combination meter and terminal MPX+ (Gray wire) at electrical connector A7 for A/C amplifier. (Scheme 16) Also, check for continuity between terminal MPX+ (Gray/Black wire) at electrical connector C11 for combination meter and terminal MPX+ (Gray/Black wire) at electrical connector B8 for body ECU. (Scheme 16) If continuity exists on both circuits, replace combination meter. If continuity does not exist on any circuit, repair wiring harness or electrical connector as necessary.

DTC exists when communication stops between multi-display and body Electronic Control Unit (ECU) for more than 10 seconds. Multi-display is located at center of instrument panel. see scheme 2 Possible causes are: defective multi-display or defective wiring harness.

1. Check that multi-display operates properly. If multi-display operates properly, go to next step. If multi-display does not operate properly, replace multi-display. See «MULTI-DISPLAY»(ref-132865-S20160898912001121400000) under REMOVAL & INSTALLATION.
2. Disconnect electrical connector at gateway ECU. Gateway ECU is located behind center of instrument panel and contains a Gray 14-pin electrical connector. see scheme 2 Disconnect electrical connector M5 at multi-display. (Scheme 13)
3. Using ohmmeter, check for continuity between terminal TX3+ (Red wire) at electrical connector M5 for multi-display and terminal GTX+ (Red wire) at gateway ECU electrical connector. (Scheme 13) Also, check for continuity between terminal TX3- (Green wire) at electrical connector M5 for multi-display and terminal GTX- (Green wire) at gateway ECU electrical connector. (Scheme 13) If continuity exists on both circuits, replace multi-display. See «MULTI-DISPLAY»(ref-132865-S20160898912001121400000) under REMOVAL & INSTALLATION. If continuity does not exist on any circuit, repair wiring harness or electrical connector as necessary.

DTC exists when communication stops between gateway Electronic Control Unit (ECU) and body ECU for more than 10 seconds. Possible causes are: defective gateway ECU or defective wiring harness.

1. Open door and check that open door indicator light turns on. Open door indicator light is located just to the left of speedometer on combination meter. (Scheme 8) Combination meter is located at center of instrument panel. see scheme 2 If open door indicator light operates properly, go to next step. If open door indicator light does not operate properly, replace gateway ECU. See «GATEWAY ELECTRONIC CONTROL UNIT»(ref-132865-S26837465272001112800000) under REMOVAL & INSTALLATION.
2. Disconnect electrical connector B8 at body ECU. see scheme 3 Body ECU is located at driver's side of instrument panel on the fuse/relay box and uses an 18-pin and 20-pin electrical connector. see scheme 3 Disconnect electrical connector at gateway ECU. Gateway ECU is located behind center of instrument panel and contains a Gray 14-pin electrical connector. see scheme 2 Note location of ECM behind the glove box. see scheme 2 Disconnect electrical connector E10 at ECM. (Scheme 14)
3. Using ohmmeter, check for continuity between terminal MPX- (Gray wire) at electrical connector B8 for body ECU and terminal MPX2 (Gray wire) at electrical connector E10 for ECM. (Scheme 14) Also, check for continuity between terminal MPX1 (Gray/Blue wire) at electrical connector E10 for ECM and terminal MPD2 (Gray/Blue wire) at gateway ECU electrical connector. (Scheme 14) If continuity exists on both circuits, replace gateway ECU. See «GATEWAY ELECTRONIC CONTROL UNIT»(ref-132865-S26837465272001112800000) under REMOVAL & INSTALLATION. If continuity does not exist on any circuit, repair wiring harness or electrical connector as necessary.