Engine Control System (Diagnostics - Introduction): Diagnosis Lexus GS IV

HOW TO PROCEED WITH TROUBLESHOOTING [03/2012 - ]

HINT

*: Use the Techstream.

1. VEHICLE BROUGHT TO WORKSHOP NEXT: Go to next step
2. CUSTOMER PROBLEM ANALYSIS NEXT: Go to next step
3. CONNECT TECHSTREAM TO DLC3* HINT: If the display indicates a communication fault with the Techstream, inspect the DLC3. When any CAN communication system DTCs are output, perform troubleshooting on the CAN communication system first. NEXT: Go to next step
4. CHECK DTC AND FREEZE FRAME DATA* Check for DTCs. Refer to «DTC CHECK / CLEAR [03/2012 - ]»(ref-600436-S38423165432014022400000) and freeze frame data. Refer to «FREEZE FRAME DATA [03/2012 - ]»(ref-600436-S42043071792014022400000) . HINT: Record or print DTCs and freeze frame data, if necessary. NEXT: Go to next step
5. CLEAR DTC AND FREEZE FRAME DATA* Clear the DTCs and freeze frame data. Refer to «DTC CHECK / CLEAR [03/2012 - ]»(ref-600436-S38423165432014022400000) . NEXT: Go to next step
6. CONDUCT VISUAL INSPECTION NEXT: Go to next step
7. SELECT CHECK MODE DIAGNOSIS* HINT: Refer to Check Mode Procedure. Refer to «CHECK MODE PROCEDURE [03/2012 - ]»(ref-600436-S08119784462014022400000) . NEXT: Go to next step
8. CONFIRM PROBLEM SYMPTOMS HINT: Refer to Problem Symptoms Table. Refer to «PROBLEM SYMPTOMS TABLE [03/2012 - ]»(ref-600436-S35965376192014022400000) . If the engine does not start, first perform the "Check DTC" procedure and "Conduct Basic Inspection" procedure below. Result Result Proceed to Malfunction does not occur A Malfunction occurs B B --> GO TO STEP 10 A: Go to next step
9. SIMULATE SYMPTOMS HINT: Refer to Problem Symptoms Table. Refer to «PROBLEM SYMPTOMS TABLE [03/2012 - ]»(ref-600436-S35965376192014022400000) . NEXT: Go to next step
10. CHECK DTC* HINT: Refer to DTC Check / Clear. Refer to «DTC CHECK / CLEAR [03/2012 - ]»(ref-600436-S38423165432014022400000) . Result Result Proceed to DTC is output A DTC is not output B B --> GO TO STEP 12 A: Go to next step
11. REFER TO DTC CHART HINT: Refer to Diagnostic Trouble Code Chart. Refer to «DIAGNOSTIC TROUBLE CODE CHART [03/2012 - ]»(ref-600436-S04366444592014022400000) . NEXT: Go to next step
12. CONDUCT BASIC INSPECTION HINT: Refer to Basic Inspection. Refer to «BASIC INSPECTION [03/2012 - ]»(ref-600436-S12280241482014022400000) . Result Result Proceed to Malfunctioning parts not confirmed A Malfunctioning parts confirmed B B --> GO TO STEP 17 A: Go to next step
13. REFER TO PROBLEM SYMPTOMS TABLE HINT: Refer to Problem Symptoms Table. Refer to «PROBLEM SYMPTOMS TABLE [03/2012 - ]»(ref-600436-S35965376192014022400000) . Result Result Proceed to Malfunctioning circuit confirmed A Malfunctioning parts confirmed B B --> GO TO STEP 17 A: Go to next step
14. CHECK ECM POWER SOURCE CIRCUIT HINT: Refer to ECM Power Source Circuit. Refer to «ECM Power Source Circuit»(ref-600578-S39722387982014022400000) . NEXT: Go to next step
15. CONDUCT CIRCUIT INSPECTION Result Result Proceed to Malfunction not confirmed A Malfunction confirmed B B --> GO TO STEP 18 A: Go to next step
16. CHECK FOR INTERMITTENT PROBLEMS HINT: Refer to Check for Intermittent Problems. Refer to «CHECK FOR INTERMITTENT PROBLEMS [03/2012 - ]»(ref-600436-S08790525922014022400000) . NEXT: Go to next step
17. CONDUCT PARTS INSPECTION NEXT: Go to next step
18. IDENTIFY PROBLEM NEXT: Go to next step
19. ADJUST AND/OR REPAIR NEXT: Go to next step
20. CONDUCT CONFIRMATION TEST NEXT --> END

BASIC INSPECTION [03/2012 - ]

When the malfunction is not confirmed by the DTC check, troubleshooting should be carried out in all circuits considered to be possible causes of the problem. In many cases, by carrying out the basic engine check shown in the following procedure, the location of the problem can be found quickly and efficiently. Therefore, using this check is essential when troubleshooting the engine.

1. CHECK AUXILIARY BATTERY VOLTAGE NOTE: Carry out this check with the engine stopped and the power switch off. Result Result Proceed to 11 V or more OK Below 11 V NG NG --> CHARGE OR REPLACE AUXILIARY BATTERY OK: Go to next step
2. CHECK WHETHER ENGINE CRANKS NG --> PROCEED TO PROBLEM SYMPTOMS TABLE. Refer to «PROBLEM SYMPTOMS TABLE [03/2012 - ]»(ref-600436-S35965376192014022400000) OK: Go to next step
3. CHECK WHETHER ENGINE STARTS NG --> GO TO STEP 6 OK: Go to next step
4. CHECK AIR CLEANER FILTER ELEMENT SUB-ASSEMBLY Visually check that the air cleaner filter element sub-assembly is not excessively contaminated with dirt or oil. NG --> REPLACE AIR CLEANER FILTER ELEMENT SUB-ASSEMBLY OK: Go to next step
5. CHECK IDLE SPEED Check the engine idle speed. Refer to «ON-VEHICLE INSPECTION [03/2012 - ] - Step 9»(ref-600560-S06547293962014022400000) . NG --> TROUBLESHOOT IDLE SPEED AND PROCEED TO NEXT STEP OK: Go to next step
6. CHECK FUEL PRESSURE Check the fuel pressure. Refer to «ON-VEHICLE INSPECTION [03/2012 - ]»(ref-600579-S01413069142014022400000) . NG --> TROUBLESHOOT FUEL PRESSURE AND PROCEED TO NEXT STEP OK: Go to next step
7. CHECK FOR SPARK Perform a spark test. Refer to «ON-VEHICLE INSPECTION [03/2012 - ] - Step 1»(ref-600580-S02040303612014022400000) . NG --> TROUBLESHOOT IGNITION SYSTEM AND PROCEED TO NEXT STEP OK --> PROCEED TO PROBLEM SYMPTOMS TABLE. Refer to «PROBLEM SYMPTOMS TABLE [03/2012 - ]»(ref-600436-S35965376192014022400000)

PROBLEM SYMPTOMS TABLE [03/2012 - ]

HINT

1. Use the table below to help determine the cause of problem symptoms. If multiple suspected areas are listed, the potential causes of the symptoms are listed in order of probability in the "Suspected Area" column of the table. Check each symptom by checking the suspected areas in the order they are listed. Replace parts as necessary.
2. Inspect the fuses and relays related to this system before inspecting the suspected areas below.

SFI SYSTEM

DTC CHECK / CLEAR [03/2012 - ]

Note. When the diagnosis system is changed from normal mode to check mode or vice versa, all DTCs and freeze frame data recorded in normal mode are cleared. Before changing modes, always check and make a note of DTCs and freeze frame data.

HINT

1. DTCs which are stored in the ECM can be displayed on the Techstream. The Techstream can display the current, pending and permanent DTCs.
2. If a malfunction is detected during the current driving cycle, current and permanent DTCs are stored.
3. Some DTCs are not stored if the ECM does not detect the same malfunction again during a second consecutive driving cycle. However, such malfunctions, detected on only one occasion, are stored as pending DTCs.
4. Current and pending DTCs can be cleared by using the Techstream or by disconnecting the cable from the negative (-) auxiliary battery terminal. However, permanent DTCs cannot be cleared using either of these two methods.
5. After clearing current DTCs using the Techstream (or by disconnecting the cable from the negative (-) auxiliary battery terminal), permanent DTCs can be cleared when the system is determined to be normal for the relevant DTCs and then the universal trip is performed. The driving pattern to obtain a normal judgment is described under the "Confirmation Driving Pattern" for the respective DTC.

2 TRIP DETECTION EXAMPLES

Scheme 2

Scheme 3

HINT

1. Obtaining a normal judgment and performing a universal trip driving pattern can be done in the same driving cycle or in different driving cycles.
2. It is unnecessary to obtain a normal judgment if the DTCs are misfire or fuel system DTCs.

Scheme 4

1. CHECK DTC Connect the Techstream to the DLC3. Turn the power switch on (IG). Turn the Techstream on. Enter the following menus: Powertrain / Engine and ECT / Trouble Codes. Check the DTC(s) and freeze frame data, and then write them down. Check the details of the DTC(s). Refer to «DIAGNOSTIC TROUBLE CODE CHART [03/2012 - ]»(ref-600436-S04366444592014022400000) .
2. CLEAR DTC (Pending and Current DTC) Connect the Techstream to the DLC3. Turn the power switch on (IG). Turn the Techstream on. Enter the following menus: Powertrain / Engine and ECT / Trouble Codes. Clear the DTCs.
3. CLEAR DTC (Pending and Current DTC without using Techstream) Perform either of the following operations: WARNING: After turning power switch off, waiting time may be required before disconnecting the cable from the negative (-) auxiliary battery terminal. Therefore, make sure to read the disconnecting the cable from the negative (-) auxiliary battery terminal notices before proceeding with work. Refer to «PRECAUTION [03/2012 - ]»(ref-600412-S33693534232014022400000) . Disconnect the cable from the negative (-) auxiliary battery terminal for more than 1 minute. Remove the EFI MAIN fuse from the No. 1 engine room relay block and junction block assembly located inside the engine compartment for more than 1 minute.
4. CLEAR PERMANENT DTC HINT: Even if the following procedure is not performed, permanent DTCs are cleared by obtaining a normal judgment during 3 consecutive driving cycles. Connect the Techstream to the DLC3. Turn the power switch on (IG). Turn the Techstream on. Enter the following menus: Powertrain / Engine and ECT / Trouble Codes. Check if permanent DTCs are stored. HINT: If permanent DTCs are not output, it is not necessary to continue this procedure. Clear the DTCs. Perform the respective confirmation driving patterns in order to obtain a normal judgment for the output DTCs. HINT: Confirmation driving patterns do not need to be performed for misfire and fuel system DTCs. For the confirmation driving pattern, refer to the procedures for the relevant DTC. Refer to «DIAGNOSTIC TROUBLE CODE CHART [03/2012 - ]»(ref-600436-S04366444592014022400000) . Perform the universal trip. WARNING: When performing the confirmation driving pattern, obey all speed limits and traffic laws. HINT: The driving pattern to obtain a normal judgment and the universal trip driving can be performed consecutively in the same driving cycle. Put the engine in inspection mode (maintenance mode). Refer to «INSPECTION MODE PROCEDURE [03/2012 - ]»(ref-600412-S34816019962014022400000) . Idle the engine for 30 seconds or more. Drive the vehicle at 40 km/h (25 mph) or more for a total of 5 minutes or more. HINT: It is possible to complete the drive pattern even if the vehicle decelerates to less than 40 km/h (25 mph) during the driving cycle provided that the vehicle is driven at 40 km/h (25 mph) or more for a total of 5 minutes. Allow 10 minutes or more to elapse from the time the engine is started. Enter the following menus: Powertrain / Engine and ECT / Trouble Codes. Check that the permanent DTCs have been cleared. HINT: The permanent DTCs are cleared when the universal trip is completed.

Scheme 5

Scheme 6

Scheme 7

1. DESCRIPTION The ECM records vehicle and driving condition information as freeze frame data the moment a DTC is stored. When troubleshooting, freeze frame data can be helpful in determining whether the vehicle was moving or stationary, whether the engine was warmed up or not, whether the air/fuel ratio was lean or rich, as well as other data recorded at the time of a malfunction. HINT: If it is impossible to replicate the problem even though a DTC is detected, confirm the freeze frame data. The ECM records engine conditions in the form of freeze frame data every 0.5 seconds. Using Techstream, five separate sets of freeze frame data, including the data values at the time when the DTC was set, can be checked. 3 data set before the DTC was set. 1 data set when the DTC was set. 1 data set after the DTC was set. These data sets can be used to simulate the condition of the vehicle around the time of the occurrence of the malfunction. The data may assist in identifying of the cause of the malfunction, and in judging whether it was temporary or not.
2. PENDING FREEZE FRAME DATA HINT: Pending freeze frame data is stored when a 2 trip DTC is first detected during the first trip. Connect the Techstream to the DLC3. Turn the power switch on (IG). Turn the Techstream on. Enter the following menus: Powertrain / Engine and ECT / Trouble Codes. Select a DTC in order to display its pending freeze frame data. HINT: Pending freeze frame data is cleared when any of the following occurs. Using the Techstream, the DTCs cleared. The cable is disconnected from the negative (-) auxiliary battery terminal. 40 trips with the engine fully warmed up have been performed after returning to normal. (Pending freeze frame data will not be cleared by only returning the system to normal.) With previous pending freeze frame data stored, if pending freeze frame data is newly stored when a 2 trip DTC is detected in the first trip, the old freeze frame data will be replaced with the new data of the newly detected DTC in the next trip.
3. LIST OF FREEZE FRAME DATA Refer to "Data List / Active Test". Refer to «DATA LIST / ACTIVE TEST [03/2012 - ]»(ref-600436-S18321174072014022400000) .

DIAGNOSTIC TROUBLE CODE CHART [03/2012 - ]

HINT

Factors such as instrument type may cause readings to differ slightly from stated values. If any DTCs are output during a check mode DTC check, check the circuit for the DTCs listed in the table below. For details of each DTC, refer to the "See" below.

*: The MIL flashes when a catalyst damaging misfire is detected.

SFI SYSTEM