Test No. 27: All Functions Of Keyless Entry System Will Not Operate

Ensure ignition is off. Disconnect electrical connector at wireless door lock Electronic Control Unit (ECU). Wireless door lock ECU is located near center of instrument panel and contains a Dark Gray 7-pin electrical connector. See Figure.
Note location of body Electronic Control Unit (ECU) at driver's side of instrument panel on the fuse/relay box. See Figure. Electrical connector I13 (7-pin or 25-pin) and electrical connector I16 (18-pin) are located at body ECU and a 12-pin electrical connector is located at rear of body ECU. See Figure. Disconnect electrical connector I16 at body ECU. See Figure.
Using ohmmeter, check for continuity between body ground and terminal No. 14 (Green/Yellow wire) at body ECU electrical connector I16. See Fig 1. If no continuity exists, go to next step. If continuity exists, repair short to ground on Green/Yellow wire between body ECU and terminal No. 4 at wireless door lock ECU. See WIRING DIAGRAMS in KEYLESS ENTRY SYSTEMS - SIENNA article. Body ECU may also be referred to as integration relay. Reinstall electrical connectors and recheck keyless entry system operation.
Using ohmmeter, check for continuity between terminal No. 15 (Green/Red wire) at body ECU electrical connector I16 and terminal No. 2 (Green/Red wire) at wireless door lock ECU electrical connector. See Fig 1. If continuity exists, reinstall electrical connectors and go to next step. If continuity does not exist, repair wiring as necessary. Reinstall electrical connectors and recheck keyless entry system operation.

Fig 1: Identifying Terminals On Body Electronic Control Unit Electrical Connector I16 & Wireless Door Lock Electronic Control Unit Electrical Connector
Courtesy of © TOYOTA, LICENSE AGREEMENT TMS1002
Replace wireless door lock ECU with a known-good wireless door lock ECU and recheck keyless entry system operation. If keyless entry system still does not operate, go to next step. If keyless entry system operates, original wireless door lock ECU was defective.
Check key unlock warning switch. See KEY UNLOCK WARNING SWITCH under COMPONENT TESTS. If key unlock warning switch is okay, go to next step. If key unlock warning switch is defective, replace key unlock warning switch and recheck keyless entry system operation. See KEY UNLOCK WARNING SWITCH under REMOVAL & INSTALLATION.
Check wiring harness and electrical connectors between key unlock warning switch and body ECU. See WIRING DIAGRAMS in KEYLESS ENTRY SYSTEMS - SIENNA article. Body ECU may also be referred to as integration relay. Key unlock warning switch may also be referred to as unlock switch or unlock warning switch. If wiring harness and electrical connectors are okay, go to next step. If wiring harness or electrical connector is defective, repair as necessary and recheck keyless entry system operation.
Check body ECU for proper voltage and input signals. See BODY ELECTRONIC CONTROL UNIT under PIN VOLTAGE TESTS. If proper voltage and input signals exist, go to next step. If proper voltage and input signals do not exist, repair as necessary and recheck keyless entry system operation.
Replace body ECU with a known-good body ECU and recheck keyless entry system operation. If keyless entry system operates properly, original body ECU was defective. If keyless entry system operation still does not operate properly, check wiring harness and electrical connectors for body ECU and key unlock warning switch for an intermittent problem. See WIRING DIAGRAMS in KEYLESS ENTRY SYSTEMS - SIENNA article. Repair wiring harness or electrical connector as necessary.