2001 Boxster S memory seat: all motors dead, relays click, mirrors still work - 986 Forum - The Community for Porsche Boxster & Cayman Owners

Completely lost at this point so would really appreciate any help or guidance. Thank you! 2001 Boxster S, driver memory seat completely dead. All seat motors stopped at once. The driver’s seat has full memory. Recently I reprogrammed the seat memory so position 1 is associated with the key/remote. A couple days later, the seat ended up in an odd position and stopped moving entirely. Current symptoms: * Driver seat does not move in any direction. * The seat adjustment levers still produce audible clicks/relay sounds when pressed. * The memory system is at least partly alive (?) as the mirrors still adjust/recall. * Passenger seat works normally. * All relevant seat fuses tested at roughly 12.5 V on both sides. * I removed the seat cushion for access. * Identified the memory-seat module connector block: * #1–4 = individual seat motor outputs * #5 = seat adjustment switch input * #6 = main power supply * #7 = large white memory/mirror/key-related connector * Unplugged and reseated #6 main power with the battery disconnected. No change. * I also unplugged/reseated the large #7 white connector. No change. * I disconnected/reconnected the car battery to fully reset the module. No change. * Manual fore/aft emergency adjustment described in the owner’s manual does not appear to exist on my particular seat motor; the motor end is just flat metal with no accessible hex socket. * I have not yet direct-powered an individual motor. * Since every motor stopped simultaneously, I’m suspecting either: * loss of the common high-current motor feed/ground, * failed internal main relay/output stage in the memory module, * or some other common module fault rather than multiple motors failing together. Main questions: 1. Has anyone seen a 986 memory-seat module fail this way, ie relay clicks but no motor output on any axis? 2. What is the best way to test the high-current supply at connector #6 under load? 3. Can I safely direct-power the fore/aft motor through connector #4 to confirm the motor/mechanism itself is good? 4. Is there any known interaction with key-memory programming that can leave the module in a locked/fault state?

I can't answer your questions, but my educated guess is that there is a fault in an internal component of the seat memory module that sits under the driver's seat. I installed full power seats in my car about 10-years ago. (I subsequently installed 997 adaptive sports seats, but that is a different story.) Most of the knowledge I acquired during the seat installation process is included in this thread: https://986forum.com/forums/boxster-general-discussions/58080-full-power-seat-installation.html Based on my experience, I suspect your problem is caused by a failed seat memory module. I asked Copilot to review your situation and here's the response: This is *exactly* the kind of failure mode on a 986-memory seat where the symptoms tell a very specific story once you line them up. Let me give you the clearest, most actionable diagnosis path you can hand back to the other owner. --- ## 🔧 **The short version:** If **all motors died at once**, **relays still click**, **mirrors still respond**, and **fuses show 12.5 V**, then the failure is almost certainly: ### **→ Loss of the high‑current motor feed inside the seat memory module** or ### **→ A failed internal H‑bridge/output stage (common driver transistor pack)** This is *the* classic 986/996 memory‑seat module failure pattern. The relay clicking proves the logic side is alive. The mirrors working proves the CAN/memory subsystem is alive. All motors dying at once proves the failure is on the **shared power path**, not the motors. --- # 🧩 **Why this failure happens** Inside the 986 memory seat module, the motor outputs share: - one **main high‑current feed** (from connector #6) - one **internal main relay** - one **H‑bridge driver pack** (MOSFET array) If the relay coil energizes but the MOSFET pack or the relay’s *high‑current contacts* fail, you get: - **click** - **no motor movement** - **no voltage at any motor output** - **mirrors still work** (different subsystem) This is exactly what he’s describing. --- # 🔍 **Answering his specific questions** ## **1. “Has anyone seen a 986 memory-seat module fail this way?”** Yes. Many times. The most common failure modes: - **Burned internal relay contacts** (logic clicks, but no current passes) - **Failed MOSFET output stage** (all motors dead simultaneously) - **Cracked solder joints** on the main feed or relay legs - **Internal thermal fuse opening** (rare but documented) This symptom set is textbook. --- ## **2. “How do I test the high‑current supply at connector #6 under load?”** Here’s the correct method: ### **A. Back‑probe connector #6 (main power)** You want to test **voltage under load**, not just static voltage. 1. Leave connector #6 plugged in. 2. Insert a thin back‑probe or sewing needle alongside the wire. 3. Connect multimeter: - **Red** to the back‑probe - **Black** to a known good chassis ground 4. Press any seat switch. ### **Expected results:** - **If voltage stays at 12–13 V → the module is receiving full power.** - **If voltage collapses → upstream wiring or fuse is failing under load.** Given the relay clicks, I expect voltage will stay stable. That points to an internal module failure. --- ## **3. “Can I safely direct‑power the fore/aft motor through connector #4?”** Yes — with two cautions. ### **Safe method:** 1. Unplug connector #4 (fore/aft motor). 2. Identify the two motor wires (it’s a simple DC motor). 3. Apply **12 V fused power** (use a 10–15 A inline fuse). 4. Reverse polarity to run the motor the opposite direction. ### **What this tells you:** - If the motor runs → the mechanical system is fine, and the module is the failure point. - If the motor does not run → the motor itself is seized or dead (rare on 986 seats). Given *all* motors died at once, the motor is almost certainly fine. --- ## **4. “Can key-memory programming lock the module?”** No. There is **no software lockout** in the 986 memory seat module. The module does not “brick” itself due to programming. Key‑linked memory only affects the logic side, not the motor driver stage. The fact that mirrors still respond to memory recall proves the logic side is functioning normally. --- # 🧪 **The definitive diagnostic test** This is the test that will tell him the truth in 30 seconds. ### **Test: Check for voltage at any motor output (connectors #1–4) while pressing a switch.** Procedure: 1. Back‑probe one of the motor output pins. 2. Press the corresponding seat switch. 3. Watch the multimeter. ### **Expected:** - **0 V always → internal module failure (relay contacts or MOSFET pack).** - **12 V appears → wiring/motor issue (but this won’t happen given his symptoms).** If he gets **0 V on all four outputs**, the module is dead. --- # 🛠️ **What the fix usually is** He has three realistic options: ### **Option A — Open the module and repair it** Common repairs: - Reflow cracked solder joints - Replace the internal relay - Replace the MOSFET driver pack - Repair burned traces These modules are very repairable. ### **Option B — Replace the module** Used modules from 986/996 memory seats are plug‑and‑play. ### **Option C — Bypass the module** If he only needs manual seat movement, you can bypass the module and run the motors directly with a DPDT switch. Not elegant, but works. --- # 🎯 **Most likely root cause** Based on his symptoms: ### **→ Failed internal main relay contacts OR failed MOSFET output stage.** This is the only failure mode that explains: - all motors dead - relay clicks - mirrors still work - fuses good - memory logic alive - no movement on any axis - no change after battery reset It’s not wiring. It’s not the motors. It’s not the switches. It’s not the key memory. It’s the module. Good luck fixing your problem.

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Thank you very much, Kevin! Just seeing this now and that’s pretty much the conclusion my junior assistant ChatGPT had reached too so I was out by the car giving the direct power a go. Between Copilot and ChatGPT, they’d done a good job I’d say and it WORKED! I confirmed the culprit was fault code 2 in seat memory with Durametric yesterday. So I got this tool from Amazon earlier today and supplied direct power with the two probes to each of the 4 adjustment connectors: Autel PowerScan Automotive... https://www.amazon.com/dp/B00UZ940ES?ref=ppx_pop_mob_ap_share For now, I’ll just leave the seat like this as I am the only one driving the car anyways, but will plan to pull out the whole module and look into servicing it at some point.

It sounds like you are on the right track. If you can find a good second-hand memory module at a reasonable price and swap it in, that may be the quickest repair option. Like you, I'm usually the only person who drives the Boxster. I want all the seat motors to function because like to make minor adjustments to my seating position - especially on longer drives.