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HOMESERVICE MANUALSTOYOTA2004MATRIX XR, FWD, STANDARDREPAIR AND DIAGNOSISEXTERNAL PAGESDIFFERENT CARSECTION 178 (POWER & HEATED SEATS)TROUBLE SHOOTING

2004 Toyota Matrix XR, FWD, Standard

Trouble Shooting

2004 Toyota Matrix XR, FWD, StandardSECTION Trouble Shooting

WARNING: This page is about a different car, the 2002 Lexus GS 430 and 2002 Lexus GS 300. However, it is still accessible from the selected car via links, so may be relevant.

Trouble shooting of a power seat and/or seat heater system complaint begins with verification of the customer problem. If problem occurs, go to step 3. If problem does not occur, go to next step.
If problem does not occur, review conditions under which problem occurred for customer and try to duplicate those conditions. For example, if the problem occurs on rainy days or during high humidity conditions, sprinkle water onto vehicle and see if malfunction occurs. DO NOT sprinkle water directly into engine compartment or onto electronic components. Visually inspect for signs of mechanical and electrical damage. Inspect for blown fuses and damaged relays. Inspect for loose or corroded connections, damaged wiring harness and/or switches. Check for a broken or partially broken wire inside insulation, which could cause system malfunction but prove good in a continuity/voltage check with system disconnected. Ensure any aftermarket electronic equipment is properly installed. If fault is found, repair as necessary.
Inspect the multiplex communication system and confirm that there is no trouble by the basic inspection and DTC check. See PRE-CHECK under SELF-DIAGNOSTIC under appropriate MULTIPLEX COMMUNICATION SYSTEM article in COMMUNICATION DEVICES.

Determine problem symptom. See PROBLEM SYMPTOM INDEX table.

PROBLEM SYMPTOM INDEX

Symptom

Suspected Area ⁽¹⁾

Power Seat System

All Functions Do Not Operate

⁽²⁾⁽³⁾

Both Driver & Passenger Power Seats Do Not Operate (Door Lock Does Not Operate)

⁽⁴⁾⁽⁵⁾

Driver's Seat Does Not Operate

⁽⁶⁾⁽⁷⁾⁽⁵⁾

Passenger's Seat Does Not Operate

⁽⁸⁾⁽⁷⁾⁽⁵⁾

Slide, Reclining, Front Vertical Or Lifter Operation Does Not Operate

⁽⁷⁾⁽⁵⁾⁽⁹⁾

Lumbar Support Operation Does Not Operate

⁽⁷⁾⁽⁵⁾⁽¹⁰⁾

Memory Return Function Does Not Operate

⁽¹¹⁾⁽³⁾

Memory Return Function Operates Normally

⁽¹²⁾⁽³⁾

Seat Heater System

Seat Heaters Do Not Operate

⁽¹³⁾⁽¹⁴⁾⁽⁵⁾⁽¹⁵⁾

Driver's Or Passenger's Seat Heater Does Not Operate

⁽¹⁴⁾⁽⁵⁾

Seat Heater Temperature Is Too Hot

⁽¹⁵⁾

⁽¹⁾	Perform test procedures in order listed under suspected area.

⁽²⁾	Check the ECU power source circuit. See ECU POWER SOURCE CIRCUIT under CIRCUIT TESTS.

⁽³⁾	Check the power seat position ECU. See PIN VOLTAGE TESTS .

⁽⁴⁾	Check the ALT M (120-amp) fuse located in the engine room No. 1 relay block.

⁽⁵⁾	Check the wiring harness. See POWER SEATS under SYSTEM WIRING DIAGRAMS article in ELECTRICAL.

⁽⁶⁾	Check the D P/SEAT (30-amp) fuse located in the drive side junction block.

⁽⁷⁾	Check the appropriate power seat switch (driver or passenger). See POWER SEAT SWITCH under COMPONENT TESTS.

⁽⁸⁾	Check the P P/SEAT (30-amp) fuse located in the passenger side junction block.

⁽⁹⁾	Check the appropriate motor (slide, front vertical, lifter or reclining). See POWER SEAT MOTOR under COMPONENT TESTS.

⁽¹⁰⁾	Check the lumbar support motor. See LUMBAR SUPPORT MOTOR under COMPONENT TESTS.

⁽¹¹⁾	Check the M1, M2 SET switch circuit. See M1, M2 SET SWITCH CIRCUIT under CIRCUIT TESTS.

⁽¹²⁾	Check the seat position sensor circuit. See SEAT POSITION SENSOR CIRCUIT under CIRCUIT TESTS.

⁽¹³⁾	Check the SEAT HTR (20-amp) fuse located in the passenger side junction block.

⁽¹⁴⁾	Check the appropriate seat heater switch (driver or passenger). See SEAT HEATER SWITCH under COMPONENT TESTS.

⁽¹⁵⁾	Check the seat heater. See SEAT HEATER under COMPONENT TESTS.

Inspect the circuits of the power seat and seat heater systems. See CIRCUIT TESTS . If the trouble still reappears in the power seat system, even though there are no abnormalities in any of the other circuits, check and replace the power seat position ECU as the last step.
After repairs have been completed, confirm that problem has been eliminated. Operate the system under same conditions recorded for original complaint. If problem is no longer present, repair has corrected problem. If problem is still present, further diagnosis and repair is required.

RENDER: 1.0x

NO RELATED

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When to See a Mechanic

Stop DIY work and contact a certified mechanic immediately if any of the following apply:

• You smell fuel, burning insulation, or see smoke.
• Brakes feel soft, pull hard to one side, or make grinding noises.
• The engine overheats, stalls repeatedly, or misfires under load.
• You are missing required tools, torque specs, or safe lifting equipment.
• You are not confident in the next step or safety outcome.