Diagnostics: Diagnosis Subaru Impreza GD/GC/GG

INSPECTION

When any on-board diagnostics item is malfunctioning, the display on the AT OIL TEMP warning light blinks from the time the malfunction is detected after starting the engine until the ignition switch is turned OFF. The malfunctioning part or unit can be determined by a trouble code during on-board diagnostics operation. Problems which occurred previously can also be identified through the memory function. If the AT OIL TEMP warning does not show a problem (although a problem is occurring), the problem can be determined by checking the performance characteristics of each sensor using the select monitor. Indicator signal is as shown in the figure.

ATF Temperature Warning Light Display Function. Scheme 681

Diagnostic Trouble Code (1 Of 2). Scheme 682

Diagnostic Trouble Code (2 Of 2). Scheme 683

DIAGNOSIS

The AT OIL TEMP warning light circuit is open or shorted.

TROUBLE SYMPTOM

1. When ignition switch is turned to ON (engine OFF), AT OIL TEMP warning light does not illuminate.
2. When on-board diagnostics is performed, AT OIL TEMP warning light remains illuminated.

AT Oil Temp Warning Light Circuit - Wiring Diagram. Scheme 684

Diagnostic Procedure - Chart (1 Of 2). Scheme 685

Diagnostic Procedure - Chart (2 Of 2). Scheme 686

DIAGNOSTIC PROCEDURE WITH TROUBLE CODE

DIAGNOSTIC TROUBLE CODES (DTC) LIST

Faulty harness connector

AT OIL TEMP warning light remains on.

Control Module Power Supply And Ground Line - Wiring Diagram. Scheme 687

Diagnostic Procedure Chart (1 Of 2). Scheme 688

Diagnostic Procedure Chart (2 Of 2). Scheme 689

Engine speed input signal circuit is open or shorted.

1. No lock-up (after engine warm-up).
2. AT OIL TEMP indicator remains on when vehicle speed is "0".

Engine Speed Signal Circuit - Wiring Diagram. Scheme 690

Trouble Code 11 - Diagnostic Chart (1 Of 2). Scheme 691

Trouble Code 11 - Diagnostic Chart (2 Of 2). Scheme 692

Input signal circuit of TCM to ATF temperature sensor is open or shorted.

Excessive shift shock.

ATF Temperature Sensor Circuit - Wiring Diagram. Scheme 693

Trouble Code 27 - Diagnostic Chart (1 Of 4). Scheme 694

Trouble Code 27 - Diagnostic Chart (2 Of 4). Scheme 695

Trouble Code 27 - Diagnostic Chart (3 Of 4). Scheme 696

Trouble Code 27 - Diagnostic Chart (4 Of 4). Scheme 697

Input signal circuit of throttle position sensor is open or shorted.

Shift point too high or too low; engine brake not effected in "3" range: excessive shift shock; excessive tight corner "braking".

Throttle Position Sensor Circuit - Wiring Diagram. Scheme 698

Trouble Code 31 - Diagnostic Chart (1 Of 4). Scheme 699

Trouble Code 31 - Diagnostic Chart (2 Of 4). Scheme 700

Trouble Code 31 - Diagnostic Chart (3 Of 4). Scheme 701

Trouble Code 31 - Diagnostic Chart (4 Of 4). Scheme 702

1. The vehicle speed signal is abnormal.
2. The circuit in combination meter is faulty.
3. The harness connector between TCM and vehicle speed sensor is in short or open.

1. Erroneous idling.
2. Engine stalls.
3. Poor driving performance.

Vehicle Speed Sensor 2 (Front) Circuit - Wiring Diagram. Scheme 703

Trouble Code 33 - Diagnostic Chart (1 Of 5). Scheme 704

Trouble Code 33 - Diagnostic Chart (2 Of 5). Scheme 705

Trouble Code 33 - Diagnostic Chart (3 Of 5). Scheme 706

Trouble Code 33 - Diagnostic Chart (4 Of 5). Scheme 707

Trouble Code 33 - Diagnostic Chart (5 Of 5). Scheme 708

Input signal circuit of TCM is open or shorted.

Excessive shift shock.

Torque Converter Turbine Speed Sensor Circuit - Wiring Diagram. Scheme 709

Trouble Code 36 - Diagnostic Chart (1 Of 3). Scheme 710

Trouble Code 36 - Diagnostic Chart (2 Of 3). Scheme 711

Trouble Code 36 - Diagnostic Chart (3 Of 3). Scheme 712

The signal circuit is open or shorted.

Excessive shift shock.

Torque Control Signal Circuit - Wiring Diagram. Scheme 713

Trouble Code 38 - Diagnostic Chart (1 Of 2). Scheme 714

Trouble Code 38 - Diagnostic Chart (2 Of 2). Scheme 715

Input signal circuit of TCM from ECM is open or shorted.

Excessive shift shock.

Intake Manifold Pressure Signal Circuit - Wiring Diagram. Scheme 716

Trouble Code 45 - Diagnostic Chart (1 Of 2). Scheme 717

Trouble Code 45 - Diagnostic Chart (2 Of 2). Scheme 718

Output signal circuit of shift solenoid 1 is open or shorted.

Does not shift.

Shift Solenoid 1 Circuit - Wiring Diagram. Scheme 719

Trouble Code 71 - Diagnostic Chart (1 Of 3). Scheme 720

Trouble Code 71 - Diagnostic Chart (2 Of 3). Scheme 721

Trouble Code 71 - Diagnostic Chart (3 Of 3). Scheme 722

Output signal circuit of shift solenoid 2 is open or shorted.

Does not shift.

Shift Solenoid 2 Circuit - Wiring Diagram. Scheme 723

Trouble Code 72 - Diagnostic Chart (1 Of 2). Scheme 724

Trouble Code 72 - Diagnostic Chart (2 Of 2). Scheme 725

Output signal circuit of low clutch timing solenoid is open or shorted.

Excessive shift shock.

Low Clutch Timing Solenoid Circuit - Wiring Diagram. Scheme 726

Trouble Code 73 - Diagnostic Chart (1 Of 3). Scheme 727

Trouble Code 73 - Diagnostic Chart (2 Of 3). Scheme 728

Trouble Code 73 - Diagnostic Chart (3 Of 3). Scheme 729

Output signal circuit of 2-4 brake timing solenoid is open or shorted.

Excessive shift shock.

2-4 Brake Timing Solenoid Circuit - Wiring Diagram. Scheme 730

Trouble Code 74 - Diagnostic Chart (1 Of 3). Scheme 731

Trouble Code 74 - Diagnostic Chart (2 Of 3). Scheme 732

Trouble Code 74 - Diagnostic Chart (3 Of 3). Scheme 733

Output signal circuit of line pressure duty solenoid or resistor is open or shorted.

Excessive shift shock.

Line Pressure Duty Solenoid Circuit - Wiring Diagram. Scheme 734

Trouble Code 75 - Diagnostic Chart (1 Of 4). Scheme 735

Trouble Code 75 - Diagnostic Chart (2 Of 4). Scheme 736

Trouble Code 75 - Diagnostic Chart (3 Of 4). Scheme 737

Trouble Code 75 - Diagnostic Chart (4 Of 4). Scheme 738

Output signal circuit of 2-4 brake duty solenoid is open or shorted.

Excessive shift shock.

2-4 Brake Duty Solenoid Circuit - Wiring Diagram. Scheme 739

Trouble Code 76 - Diagnostic Chart (1 Of 4). Scheme 740

Trouble Code 76 - Diagnostic Chart (2 Of 4). Scheme 741

Trouble Code 76 - Diagnostic Chart (3 Of 4). Scheme 742

Trouble Code 76 - Diagnostic Chart (4 Of 4). Scheme 743

Output signal circuit of lock-up duty solenoid is open or shorted.

No "lock-up" (after engine warm-up).

Lock-Up Duty Solenoid Circuit - Wiring Diagram. Scheme 744

Trouble Code 77 - Diagnostic Chart (1 Of 4). Scheme 745

Trouble Code 77 - Diagnostic Chart (2 Of 4). Scheme 746

Trouble Code 77 - Diagnostic Chart (3 Of 4). Scheme 747

Trouble Code 77 - Diagnostic Chart (4 Of 4). Scheme 748

Output signal circuit of transfer duty solenoid is open or shorted.

Excessive "braking" in tight corners.

Transfer Duty Solenoid Circuit - Wiring Diagram. Scheme 749

Trouble Code 79 - Diagnostic Chart (1 Of 3). Scheme 750

Trouble Code 79 - Diagnostic Chart (2 Of 3). Scheme 751

Trouble Code 79 - Diagnostic Chart (3 Of 3). Scheme 752

Input signal circuit of TCM is open or shorted.

No lock-up or excessive tight corner "braking".

Vehicle Speed Sensor 1 (Rear) Circuit - Wiring Diagram. Scheme 753

Trouble Code 93 - Diagnostic Chart (1 Of 3). Scheme 754

Trouble Code 93 - Diagnostic Chart (2 Of 3). Scheme 755

Trouble Code 93 - Diagnostic Chart (3 Of 3). Scheme 756

Gear Position - Diagnostic Chart. Scheme 757

1. LED does not come on even if FWD switch is ON.
2. FWD switch circuit is open or short.

FWD Switch Circuit - Wiring Diagram. Scheme 758

FWD Switch - Diagnostic Chart (1 Of 2). Scheme 759

FWD Switch - Diagnostic Chart (2 Of 2). Scheme 760

Brake Switch - Diagnostic Chart. Scheme 761

ABS Switch - Diagnostic Chart. Scheme 762

Cruise Control Switch - Diagnostic Chart. Scheme 763

Input signal circuit of inhibitor switch is open or shorted.

1. Shift characteristics are erroneous.
2. Engine brake is not effected when selector lever is in "3" range.
3. Engine brake is not effected when selector lever is in "2" range.
4. Engine brake is not effected when selector lever is in "1" range.

Inhibitor Switch Circuit - Wiring Diagram. Scheme 764

Inhibitor Switch - Diagnostic Chart (1 Of 8). Scheme 765

Inhibitor Switch - Diagnostic Chart (2 Of 8). Scheme 766

Inhibitor Switch - Diagnostic Chart (3 Of 8). Scheme 767

Inhibitor Switch - Diagnostic Chart (4 Of 8). Scheme 768

Inhibitor Switch - Diagnostic Chart (5 Of 8). Scheme 769

Inhibitor Switch - Diagnostic Chart (6 Of 8). Scheme 770

Inhibitor Switch - Diagnostic Chart (7 Of 8). Scheme 771

Inhibitor Switch - Diagnostic Chart (8 Of 8). Scheme 772

Checking FWD Light - Diagnostic Chart. Scheme 773

Symptom Related - Diagnostic Chart (1 Of 5). Scheme 774

Symptom Related - Diagnostic Chart (2 Of 5). Scheme 775

Symptom Related - Diagnostic Chart (3 Of 5). Scheme 776

Symptom Related - Diagnostic Chart (4 Of 5). Scheme 777

Symptom Related - Diagnostic Chart (5 Of 5). Scheme 778