TROUBLE SHOOTING
Note. Prior to trouble shooting, ensure no problems exist in multiplex communications. If problems exist, repair multiplex control system before trouble shooting. See MULTIPLEX CONTROL SYSTEMS - LS430 article.
Note. Check circuits and components in listed order. See BODY NO. 2 CONTROL SYSTEM , BODY NO. 3 CONTROL SYSTEM , BODY NO. 4 CONTROL SYSTEM and BODY NO. 5 CONTROL SYSTEM table. If circuits or components are okay, return to trouble shooting and identify next circuit to be checked.
| Problem | Inspect | |
|---|---|---|
| Lighting System | ||
| Headlights Do Not Operate (Low Beam) | (1) Light Control Switch Circuit (1) Headlight Relay Circuit (2) Combination Switch (3) Body No. 2 ECU | |
| Headlights Do Not Operate (High Beam Or Flash) | (1) High-Beam Circuit (1) Light Control Switch Circuit (2) Combination Switch (3) Front Light ECU (3) Body No. 2 ECU | |
| Automatic Light Control System Does Not Operate | (4) Automatic Light Control Sensor Circuit (2) Combination Switch (3) Front Light ECU (3) Body No. 2 ECU | |
| Both Headlights Do Not Operate | (1) Headlight Circuit (1) Light Control Switch Circuit (2) Combination Switch (3) Front Light ECU (3) Body No. 2 ECU | |
| Fog Lights Do Not Operate | (1) Fog Light Circuit (1) Light Control Switch Circuit (2) Combination Switch (3) Front Light ECU (3) Body No. 2 ECU | |
| Rear Combination Light Does Not Operate | (1) Power Source Circuit (2) Combination Switch (3) Body No. 2 ECU (3) Body No. 4 ECU | |
| Both Taillights Do Not Operate | (1) Taillight Circuit (1) Light Control Switch Circuit (2) Combination Switch (3) Body No. 2 ECU (3) Body No. 4 ECU | |
| Stoplights Do Not Operate | (1) Stoplight Circuit (2) Combination Switch (3) Body No. 2 ECU (3) Body No. 4 ECU | |
| High-Mounted Stoplight Does Not Operate | (1) High-Mounted Stoplight Circuit (2) Combination Switch (3) Body No. 2 ECU (3) Body No. 4 ECU | |
| Back-Up Lights Do Not Operate | (1) Back-Up Light Circuit (2) Combination Switch (3) Body No. 2 ECU (3) Body No. 4 ECU | |
| License Plate Light Does Not Operate | (1) License Plate Light Circuit (2) Combination Switch (3) Body No. 2 ECU (3) Body No. 4 ECU | |
| Parking Lights Does Not Operate | (1) Parking Light Circuit (1) Light Control Switch Circuit (2) Combination Switch (3) Body No. 5 ECU (3) Body No. 2 ECU | |
| Side Marker Lights Do Not Operate | (1) Side Marker Light Circuit (2) Combination Switch Circuit (3) Body No. 5 ECU (3) Body No. 2 ECU | |
| Automatic Light Turn-Off System Does Not Operate (Headlights Normal) | (1) Headlight Circuit (1) Light Control Switch Circuit (2) Combination Switch (3) Body No. 2 ECU | |
| Turn Signal & Hazard Warning System | ||
| Hazard Warning Light Does Not Operate | (1) Hazard Switch Circuit (2) Combination Switch (3) Body No. 5 ECU (3) Body No. 2 ECU | |
| All Turn Signal Lights Do Not Operate | (1) Turn Signal Light Circuit (1) Light Control Switch Circuit (2) Combination Switch (3) Body No. 5 ECU (3) Body No. 2 ECU | |
| Illumination Light System | ||
| All Switch Illumination Does Not Operate | (1) Power Source Circuit (1) Rheostat Light Control Volume Circuit (3) Body No. 2 ECU | |
| Some Switch Illumination Does Not Operate | (1) Illumination Light Circuit (3) Body No. 2 ECU | |
| Brightness Does Not Change (All) | (1) Rheostat Light Control Volume Circuit (3) Body No. 2 ECU | |
| Brightness Does Not Change (Cluster Only) | (1) Rheostat Light Control Volume Circuit (1) Instrument Cluster Circuit (3) Body No. 2 ECU | |
| Driver Seat Belt Buckle Does Not Illuminate | (1) Driver Buckle Illumination Circuit (3) Body No. 2 ECU | |
| Glove Compartment Door Light Does Not Illuminate | (1) Illumination Light Circuit (3) Body No. 2 ECU | |
| Stoplight System | ||
| Stoplights Do Not Operate | (1) Stoplight Switch Circuit (1) Stoplight Circuit (3) Body No. 2 ECU | |
| Headlight Cleaner System | ||
| Headlight Cleaner System Does Not Operate | Headlight Cleaner Nozzle & Hose (1) Headlight Cleaner Switch Circuit (1) Headlight Cleaner Motor Circuit (1) Headlight Cleaner Relay Circuit (3) Body No. 2 ECU | |
| Driver Seat Belt System | ||
| Driver Seat Belt Warning Does Not Illuminate | (1) Driver Buckle Switch Circuit (3) Body No. 2 ECU | |
| Driver Seat Belt Electric Tension Reducer System Does Not Operate | (1) Driver Buckle Switch Circuit (1) Driver Tension Reducer Circuit (3) Body No. 2 ECU | |
| Power Shoulder Belt Anchorage System | ||
| Driver Belt Anchor Cannot Be Operated Manually | (1) Power Source Circuit (1) Shoulder Belt Anchor Motor Circuit (1) Shoulder Belt Anchor Sensor Circuit (3) Driver Door ECU (3) Body No. 2 ECU | |
| Additional Systems | ||
| Stoplight Switch Signal Is Sent To Shift Lock, VSC and Engine Control System | (1) Stoplight Switch Circuit (3) Body No. 2 ECU | |
| (1) Perform appropriate circuit test under CIRCUIT TESTS . If more than one circuit test is listed, perform tests in order listed. (2) See STEERING COLUMN SWITCHES article. (3) Perform appropriate pin voltage test under PIN VOLTAGE TESTS . (4) See appropriate Diagnostic Trouble Code (DTC) test under SELF-DIAGNOSTIC SYSTEM. | ||
| (1) | Perform appropriate circuit test under CIRCUIT TESTS . If more than one circuit test is listed, perform tests in order listed. |
| (2) | See STEERING COLUMN SWITCHES article. |
| (3) | Perform appropriate pin voltage test under PIN VOLTAGE TESTS . |
| (4) | See appropriate Diagnostic Trouble Code (DTC) test under SELF-DIAGNOSTIC SYSTEM. |
BODY NO. 2 CONTROL SYSTEM
| Problem | Inspect | |
|---|---|---|
| Interior Light System | ||
| All Interior Lights Do Not Operate | (1) Power Source Circuit (1) Illumination Light Circuit (2) Body No. 3 ECU | |
| Seat Belt Buckle Illumination Does Not Operate | (1) Passenger Buckle Illumination Circuit (2) Body No. 3 ECU | |
| Outer Step Light (In Outer Mirror) Does Not Operate | (1) Illumination Circuit (2) Body No. 3 ECU | |
| Passenger Seat Belt System | ||
| Passenger Seat Belt Electric Tension Reducer System Does Not Operate | (1) Passenger Buckle Switch Circuit (1) Passenger Tension Reducer Circuit (2) Body No. 3 ECU | |
| Power Shoulder Belt Anchorage System | ||
| Passenger Belt Anchor Cannot Be Operated Manually | (1) Shoulder Belt Anchor Motor Circuit (2) Body No. 3 ECU (3) Driver Door ECU | |
| Wiper & Washer System | ||
| Wiper & Washer System Does Not Operate | (1) Power Source Circuit (1) Wiper Motor Circuit (2) Body No. 3 ECU | |
| Wiper System Does Not Operate (High Speed) | (1) Wiper High Switch Circuit (2) Body No. 3 ECU | |
| Washer Fluid Does Not Operate | Washer Hose & Nozzle | |
| With Wiper At High Position, Wiper Blade Is In Contact With Body. With Wiper Switch Off, Wiper Blade Does Not Retract Or Retract Position Is Wrong. | (1) Wiper High Switch Circuit (1) Wiper Motor Circuit (2) Body No. 3 ECU | |
| Washer System Does Not Operate | (1) Washer Motor Does Not Operate (2) Body No. 3 ECU | |
| Washer Fluid Level Warning System Does Not Operate | (1) Washer Fluid Level Warning Switch Circuit (2) Body No. 3 ECU | |
| Additional Systems | ||
| Navigation System Abnormal | (1) Navigation ECU Communication Circuit, (1) Navigation ECU (1) Multi Display ECU (2) Body No. 3 ECU | |
| Shift Point Too High Or Too Low | (1) Pattern Select Switch Circuit (1) Shift Lock ECU | |
| Rear Sunshade Abnormal | (1) Rear Sunshade ECU Circuit (2) Body No. 3 ECU | |
| Brake Pad Indicator Does Not Operate | (1) Instrument Cluster (1) Brake Pad Sensor (4) ABS System | |
| Rear Seat Control System Does Not Operate | (1) Rear Seat Return Switch Circuit (3) Right Or Left Rear Seat ECU (2) Body No. 3 ECU | |
| (1) Perform appropriate circuit test under CIRCUIT TESTS . If more than one circuit test is listed, perform tests in order listed. (2) Perform appropriate pin voltage test under PIN VOLTAGE TESTS . (3) See MULTIPLEX CONTROL SYSTEMS - LS430 article. (4) See ANTI LOCK - LS430 article in BRAKES. | ||
| (1) | Perform appropriate circuit test under CIRCUIT TESTS . If more than one circuit test is listed, perform tests in order listed. |
| (2) | Perform appropriate pin voltage test under PIN VOLTAGE TESTS . |
| (3) | See MULTIPLEX CONTROL SYSTEMS - LS430 article. |
| (4) | See ANTI LOCK - LS430 article in BRAKES. |
BODY NO. 3 CONTROL SYSTEM
| Problem | Inspect |
|---|---|
| Luggage Room Junction Block Control System Does Not Operate | (1) Power Source Circuit (1) Ignition Switch Power Source Circuit (2) Body No. 4 ECU |
| Rear A/C Does Not Operate | (1) Rear A/C Amplifier Circuit (3) A/C ECU (2) Body No. 4 ECU |
| Fuel Lid Opener System Does Not Operate | (1) Fuel Lid Opener Motor Circuit (2) Body No. 4 ECU |
| Luggage Compartment Door Opener Or Closer System Does Not Operate | (1) Luggage Compartment Door Opener Switch Circuit (1) Luggage Compartment Door Courtesy Switch Circuit (1) Luggage Compartment Door Switch Circuit (1) Luggage Compartment Door Key Lock & Unlock Switch Circuit (1) Luggage Door Lock Switch Circuit (1) Luggage Compartment Door Motor Circuit (2) Body No. 4 ECU |
| Fuel Sender Gauge Does Not Operate | (4) Fuel Sender Gauge Circuit (2) Body No. 4 ECU |
| Luggage Compartment Light Does Not Light | (1) Luggage Compartment Light Circuit (1) Luggage Compartment Door Courtesy Switch Circuit (2) Body No. 4 ECU |
| (1) Rear Seat Belt Buckle Light Does Not Come On | (1) Rear Seat Belt Buckle Illumination Light Circuit (2) Body No. 4 ECU |
| (1) Perform appropriate circuit test under CIRCUIT TESTS . If more than one circuit test is listed, perform tests in order listed. (2) Perform appropriate pin voltage test under PIN VOLTAGE TESTS . (3) See AUTOMATIC A/C-HEATER SYSTEMS - LS430 article in AIR CONDITIONING & HEATING. (4) See INSTRUMENT PANELS - LS430 article. | |
| (1) | Perform appropriate circuit test under CIRCUIT TESTS . If more than one circuit test is listed, perform tests in order listed. |
| (2) | Perform appropriate pin voltage test under PIN VOLTAGE TESTS . |
| (3) | See AUTOMATIC A/C-HEATER SYSTEMS - LS430 article in AIR CONDITIONING & HEATING. |
| (4) | See INSTRUMENT PANELS - LS430 article. |
BODY NO. 4 CONTROL SYSTEM
| Problem | Inspect |
|---|---|
| Front Light Control Systems (Headlights, Clearance Lights, Front Fog Lights, Horn, Washer System and Washer Fluid Level Warning | (1) Power Source Circuit (1) Ignition Switch Power Source Circuit (2) Body No. 5 ECU |
| Horn Does Not Sound | (1) Horn Circuit (2) Body No. 5 ECU |
| (1) Perform appropriate circuit test under CIRCUIT TESTS . If more than one circuit test is listed, perform tests in order listed. (2) Perform appropriate pin voltage test under PIN VOLTAGE TESTS . | |
| (1) | Perform appropriate circuit test under CIRCUIT TESTS . If more than one circuit test is listed, perform tests in order listed. |
| (2) | Perform appropriate pin voltage test under PIN VOLTAGE TESTS . |
BODY NO. 5 CONTROL SYSTEM
Using Scan Tool
Multiplex self-diagnostic system DTCs are retrieved through Data Link Connector 3 (DLC3). DLC3 is located under left side of instrument panel. Connect scan tool to DLC3. Turn ignition on. Follow scan tool instructions to retrieve DTCs. See DIAGNOSTIC TROUBLE CODE INDEX table. If a DTC is present, perform appropriate test. See DIAGNOSTIC TESTS .
| DTC | Description |
|---|---|
| B1244 | Light Sensor Circuit Malfunction |
| B1268 | Back-Up Communication Bus Malfunction |
| B1268 | Back-Up Communication Bus Malfunction Between Body No. 2 ECU & Body No. 4 ECU |
| B2402, B2403 | Transistor Relay Overload Malfunction & Transistor Relay Overheat Malfunction |
DIAGNOSTIC TROUBLE CODE INDEX
CLEARING DIAGNOSTIC TROUBLE CODES
Note. DTCs will be cleared from memory when DTC is normally retrieved.