DESCRIPTION & OPERATION 1999 ACCESSORIES & EQUIPMENT Engine Immobilizer Systems - LX470 WARNING: Deactivate air bag system before performing any service operation. See AIR BAG RESTRAINT SYSTEMS article. DO NOT apply electrical power to any component on steering column without first deactivating air bag system. Air bag may deploy. The engine immobilizer system consists of an Engine Control Module (ECM), transponder key coil, transponder key amplifier and key with built-in transponder chip. See Fig. 1. When ignition key is inserted in ignition, the transponder chip in the key transmits an electronic code to the transponder key coil. The signal is amplified, and read by the ECM. The engine will start only when the key code is the same as the code registered in the ECM. System is reset each time key is removed from ignition switch. If a problem exists in the engine immobilizer system, a Diagnostic Trouble Code (DTC) may be stored in the Engine Control Module (ECM), but the Malfunction Indicator Light (MIL) on instrument cluster will not illuminate.
Fig. 1: Identifying Engine Immobilizer System Components Courtesy of TOYOTA MOTOR SALES, U.S.A., INC. PROGRAMMING
NEW TRANSPONDER KEY CODE This must be done when new ECM is installed. The new ECM is in automatic key code registration mode. Up to 4 key codes can be registered at one time. In automatic registration mode, last key registered becomes sub-key. Master key is a Black key that opens all locks. Sub-key is a Gray key that will not open glove box. 1. Security indicator will flash until first key is inserted into ignition switch. Insert NEW key in ignition switch. Security indicator should illuminate. 2. Once key registration is under way, security indicator should turn off. After key registration is complete, security indicator should illuminate. Remove NEW key. 3. If programming additional keys, repeat process starting with step 1. If additional keys do not need programming, procedure is complete. Security indicator should go out once last key (sub-key) is registered. Depress and release brake pedal at least 5 times within 15 seconds, or request automatic registration mode completion using LEXUS scan tool. 4. After registration is complete and system is operating normally, when ignition key is removed from ignition lock cylinder, security indicator should flash indicating system is properly functioning. If a key is not inserted into ignition switch with ECM in automatic registration mode, security indicator will remain illuminated indicating keys have not been registered. If ignition key registration can not be completed with Engine Control Module (ECM) in automatic registration mode, a code 2-1 will be displayed by security indicator, and when inserting the already registered ignition key, a code 2-2 will be displayed by security indicator. ADDITIONAL MASTER KEY Additional master key may be registered by 2 different methods: using brake pedal and accelerator pedal, or using LEXUS scan tool. It is possible to register up to 7 master key codes including the already registered key code. Using Brake & Accelerator Pedal 1. Insert registered master key in ignition. 2. Perform this step within 15 seconds. Depress and release accelerator pedal 5 times. 3. Perform this step within 20 seconds. Depress and release brake pedal 6 times. Remove master key from ignition. 4. Perform this step within 10 seconds. Insert new key to be registered in ignition. 5. Perform this step within 10 seconds. Depress and release accelerator pedal one time. Security indicator should flash. 6. After one minute, additional master key is registered. Security indicator should turn off. If programming additional keys, repeat process starting with step 4. If additional keys do not need programming, remove master key from ignition. Depress and release brake pedal at least once after security indicator has been out for 10 seconds to complete registration mode.
Using LEXUS Scan Tool 1. Insert registered master key in ignition. 2. Perform this step within 2 minutes. Select master key registration using LEXUS scan tool. 3. Perform this step within 20 seconds. Remove master key. 4. Perform this step within 10 seconds. Insert master key to be registered in ignition. Security indicator should flash. After one minute, additional master key is registered. Security indicator should turn off. 5. If programming additional keys, repeat process starting with step 4. If additional keys do not need programming, remove master key from ignition. Depress and release brake pedal at least once after security indicator has been out for 10 seconds to complete registration mode. ADDITIONAL SUB-KEY Additional sub-key may be registered by 2 different methods: using brake pedal and accelerator pedal, or using LEXUS scan tool. It is possible to register up to 3 sub-key codes including the already registered key code. Using Brake & Accelerator Pedal 1. Insert registered master key in ignition. 2. Perform this step within 15 seconds. Depress and release accelerator pedal 4 times. 3. Perform this step within 20 seconds. Depress and release brake pedal 5 times. Remove master key from ignition. 4. Perform this step within 10 seconds. Insert new key to be registered in ignition. 5. Perform this step within 10 seconds. Depress and release accelerator pedal one time. Security indicator should flash. 6. After one minute, additional sub-key is registered. Security indicator should turn off. If programming additional keys, repeat process starting with step 4. If additional keys do not need programming, remove master key from ignition. Depress and release brake pedal at least once after security indicator has been out for 10 seconds to complete registration mode. Using LEXUS Scan Tool 1. Insert registered master key in ignition. 2. Perform this step within 2 minutes. Select sub-key registration using LEXUS scan tool. 3. Perform this step within 20 seconds. Remove master key. 4. Perform this step within 10 seconds. Insert key to be registered in ignition. Security indicator should flash. After one minute, additional sub-key is registered. Security indicator should turn off. 5. If programming additional keys, repeat process starting with step 4. If additional keys do not need programming, remove master key from ignition. Depress and release brake pedal at least once after security indicator has been out for 10 seconds to complete registration mode. ERASURE OF TRANSPONDER KEY CODE
There are 2 different methods to erase the transponder key code: using brake pedal and accelerator pedal, or using LEXUS scan tool. All other master and sub-key codes are deleted leaving the master key code which was used when performing the operation. When using the ignition key which was used before deleting, it is necessary to register the code again. Using Brake & Accelerator Pedal 1. Insert master key in ignition. 2. Perform this step within 15 seconds. Depress and release accelerator pedal 6 times. 3. Perform this step within 20 seconds. Depress and release brake pedal 7 times. Security indicator should flash. 4. Perform this step within 10 seconds. Remove master key. Security indicator should flash. Procedure is now completed. Key code should now be erased. If key cannot be removed from ignition, key code deletion is canceled. Security indicator will turn off. Repeat procedure from step 1. Using LEXUS Scan Tool 1. Insert master key in ignition. 2. Perform this step within 2 minutes. Request key code deletion from LEXUS scan tool. Security indicator should flash. 3. Perform this step within 10 seconds. Remove master key. 4. Procedure is now completed. Key code should now be erased. If key cannot be removed from ignition, key code deletion is canceled. Security indicator will turn off. Repeat procedure from step 1. TROUBLE SHOOTING Perform immobilizer system self-diagnostics before performing trouble shooting. See DIAGNOSTIC PROCEDURE under SELF-DIAGNOSTIC SYSTEM. TROUBLE SHOOTING SYMPTOMS Problem Inspect Immobilizer Not Set (Engine Starts W/Incorrect Key (1) ECM Codes) Engine Does Not Start (2) Key; (1) Wiring Harness; (3) Transponder Key Coil; Amplifier; (1) ECM Security Indicator Is Always On (4) Security Indicator; (1) Wiring Harness; (1) ECM Security Indicator Always On (Although Code Has Been (1) Wiring Harness; (3) Transponder Key Registered In Automatic Registration Mode) Coil; Amplifier; (1) ECM Security Indicator Is Off (When Immobilizer DTC Is (1) Wiring Harness; (3) Transponder Key Output) Coil; Amplifier; (1) ECM;
Security Indicator Is Off (When Immobilizer DTC Is Not Output) Security Indicator Is Flashing Abnormally SELF-DIAGNOSTIC SYSTEM DIAGNOSTIC PROCEDURE Using Scan Tool Connect LEXUS or OBDII scan tool to Data Link Connector 3 (DLC3) located under left side of instrument panel. Turn ignition switch to ON position. Using scan tool, check DTCs and freeze frame data. If DTC 99 is retrieved, see TROUBLE SHOOTING SYMPTOMS table under TROUBLE SHOOTING. If any other DTCs are retrieved, see ENGINE IMMOBILIZER DTC DEFINITIONS table. Each DTC will be displayed in order, starting with lowest DTC. Erase DTCs using scan tool, disconnecting battery or removing EFI fuse. Using Jumper Wire (1) Wiring Harness; (1) ECM (1) Wiring Harness; (1) ECM (1) Check for opens or shorts in wiring. See WIRING DIAGRAMS. Perform ECM PIN VOLTAGE TESTS under COMPONENT TESTS. Repair or replace components as necessary. (2) Ensure key used to start engine is registered. Also check to see if vehicle will start with other registered keys. (3) Check transponder key coil. See TRANSPONDER KEY COIL under COMPONENT TESTS. (4) Complete automatic registration mode. See NEW TRANSPONDER KEY CODE under PROGRAMMING. Turn ignition switch to ON position. Locate Data Link Connector 1 (DLC1) in engine compartment, on right inner fender panel. Using a fused jumper wire, connect Data Link Connector 1 (DLC1) terminal No. 11 (Tc) and terminal No. 3 (E1). See Fig. 2. Read Malfunction Indicator Light (MIL) in instrument cluster. If DTC 99 is retrieved, see TROUBLE SHOOTING SYMPTOMS table under TROUBLE SHOOTING. If any other DTCs are retrieved, see ENGINE IMMOBILIZER DTC DEFINITIONS table. Each DTC will be displayed in order, starting with lowest DTC. After checking DTCs, disconnect jumper wire to turn off display. Erase DTCs by disconnecting battery or removing EFI fuse. ENGINE IMMOBILIZER DTC DEFINITIONS DTC Definition B2795 Unmatched Key Code B2796 No Communication In Immobilizer System B2797 Communication Malfunction No. 1 B2798 Communication Malfunction No. 2
Fig. 2: Identifying Data Link Connector 1 (DLC1) Terminals Courtesy of TOYOTA MOTOR SALES, U.S.A., INC. DIAGNOSTIC TESTS DTC B2795: UNMATCHED KEY CODE DTC B2795 is output when a key that has not been registered is inserted into ignition switch. If this DTC is output, clear DTC. Check all customer keys until key is found that is not registered. Register this key. See appropriate key programming procedure under PROGRAMMING. DTC B2796: NO COMMUNICATION IN IMMOBILIZER SYSTEM 1. Check transponder key coil. See TRANSPONDER KEY COIL under COMPONENT TESTS. Replace transponder key coil as necessary, and retest system operation. If transponder key coil is okay, go to next step. 2. Check circuits and connectors for faults between transponder key amplifier and ECM. See WIRING DIAGRAMS. Repair or replace wiring as necessary, and retest system operation. If circuits and connectors are okay, go to next step.
3. Replace transponder key amplifier. Check system operation. If system operates normally after replacing original transponder key amplifier, no further testing is required. If system still does not operate normally after replacing original transponder key amplifier, check ECM. See ECM PIN VOLTAGE TESTS under COMPONENT TESTS. If ECM is defective, replace ECM and retest system operation. DTC B2797: COMMUNICATION MALFUNCTION NO. 1 1. Insert registered key into ignition switch. Using an oscilloscope or LEXUS scan tool, check for noise interference at ECM connector E10 terminal No. 12 (Blue/Black wire). See Fig. 3. If no noise is detected, go to next step. If noise is detected, find where noise interference is coming from, and repair as necessary. Retest system operation. 2. Replace transponder key amplifier. Check system operation. If system operates normally after replacing original transponder key amplifier, no further testing is required. If system still does not operate normally after replacing original transponder key amplifier, check ECM. See ECM PIN VOLTAGE TESTS under COMPONENT TESTS. If ECM is defective, replace ECM and retest system operation. DTC B2798: COMMUNICATION MALFUNCTION NO. 2 1. Check transponder key coil. See TRANSPONDER KEY COIL under COMPONENT TESTS. Replace transponder key coil as necessary, and retest system operation. If transponder key coil is okay, go to next step. 2. Check circuits and connectors for faults between transponder key amplifier and ECM. See WIRING DIAGRAMS. Repair or replace wiring as necessary, and retest system operation. If circuits and connectors are okay, go to next step. 3. Replace transponder key amplifier. Check system operation. If system operates normally after replacing original transponder key amplifier, no further testing is required. If system still does not operate normally after replacing original transponder key amplifier, check ECM. See ECM PIN VOLTAGE TESTS under COMPONENT TESTS. If ECM is defective, replace ECM and retest system operation. COMPONENT TESTS ECM PIN VOLTAGE TESTS Turn ignition switch to ON position. Using a voltmeter, check voltage between specified terminals of ECM. See Fig. 3. See ECM TERMINAL VOLTAGE SPECIFICATIONS table. If voltage is not as specified, repair wiring harness or replace components as necessary. If voltages are as specified, replace ECM. ECM TERMINAL VOLTAGE SPECIFICATIONS Check Voltage Between Terminals Voltage E10-12 (Blue/Black Wire) & E7-17 (Brown Wire) 10-14 E10-13 (Violet/Green Wire) & E7-17 (Brown Wire) 10-14 E10-14 (Red/Yellow Wire) & E7-17 (Brown Wire) 10-14
Fig. 3: Identifying ECM Terminals Courtesy of TOYOTA MOTOR SALES, U.S.A., INC. TRANSPONDER KEY COIL Check continuity between transponder key coil terminals No. 1 and 2. If continuity does not exist, replace transponder key coil. REMOVAL & INSTALLATION Removal and installation procedures not available from manufacturer. WIRING DIAGRAMS For LX470 wiring diagrams, see ENGINE PERFORMANCE article in WIRING DIAGRAMS.