Skip to main content

MERCEDES W203 FACELIFT: GEARBOX ISSUE, DRIVE IN LIMP MODE. NOT ABLE TO SHIFT TO REVERSE OR PARKING

Transmission Issue: Unable to Detect Gear Location


Fig 1: Symptom of Gear status unknown

Symptoms:

  • Gear status unknown (as in the picture above: Fig 1)
  • When attempting to reset, the car can move, but in "Drive" mode, it only operates in limp mode.
  • Unable to shift gears to "Reverse" (R) or "Park" (P), only to "Neutral" (N).

Observed Behavior:

  • Limp mode activated.
  • Gear status not detected.
  • In "Drive" (D) mode, the car moves but only in limp mode.
  • Gear cannot be shifted to "Reverse" or "Park."

Troubleshooting and Rectification Steps

Initial Steps:

  1. Perform a gearbox reset. If the problem persists, proceed to the next steps.
  2. Verify the last gearbox service. If it is still within the recommended service interval, follow these solutions:

Solution 1: TCU Check and Cleaning

  • Remove the Transmission Control Unit (TCU) and inspect it.
  • Heat the TCU board (the electrical board inside Fig 2) in an oven at 200°C for 6-8 minutes to reflow the soldering.
  • Reinstall the TCU and test.
  • If the problem persists, proceed to the next step.

Fig 2: TCU body (inside is the control circuit)

Fig 3: TCU location on passenger side




Solution 2: Gear Shift Selector Inspection

  • Remove and inspect the gear shift selector in the centre console (Fig 4).
  • If needed, heat the selector board (Fig 5) in an oven at 200°C for 8 minutes to reflow the soldering.
  • Reinstall and test.
  • If the issue is resolved after reheating, the selector is likely the cause.
  • If the problem remains, proceed to Solution 3.
Fig 4: Gear shift selector on the center console

Fig 5: Board inside gear shift selector




Solution 3: Gearbox Components
If the issue persists, it may be a more significant problem with the gearbox. Troubleshoot in the following order:

  1. Conductor Plate:

    • Replace the conductor plate, ideally with the solenoid included, as this component may be causing incorrect gear signal transmission. (Fig 6)

  2. Valve Solenoid:

    • If replacing the conductor plate does not solve the issue, replace the valve solenoid.

  3. Professional Consultation:

    • If none of the above solutions work, the problem may require dismantling the gearbox. Seek professional assistance.


      Fig 6: Conductor plate



Fig 7: Valve and solenoid with conductor plate


Need help repairing gear selectors in Malaysia?
can PM me through email



Labels:

Comments

Post a Comment

Popular posts from this blog

HONDA RS150 TPS: RPM TAK STABIL BILA NOT ON THROTTLE DAN PENYELESAIANNYA

Assalamualaikum dan salam sejahtera Isu TPS ni berlaku pada tahun lepas, Ogos 2020 (milage dalam 24000km, baru dua tahun pakai) sewaktu saya on the way ke KL Masa tu tunggang motor full throttle yang menyebabkan RPM nya selalu mencecah ke CUT-OFF (utk makluman, honda RS150 saya ni tak guna ECU custom, masih guna yang standard). Jadi saya perasan, bila selalu tunggang pada RPM yang sampai CUTT-OFF, ini menyebabkan kesan tak baik pada TPS..jadi utk yang belum jadi problem TPS ni..boleh la cepat ganti ECU ke ECU yang tanpa cutoff. APA TU TPS? TPS bermaksud Throttle positioning sensor..bahasa mudahnya alat ni bertujuan untuk mengesan kedudukan throttle body valve dimana udara masuk ke enjin untuk pembakaran. Dengan itu, baru la ECU tahu berapa banyak bahan bakar yang perlu utk pembakaran berdasarkan bukaan valve tu.  Bila TPS dah problem, TPS akan memberi maklumat yang salah pada ECU berkenaan besar mana valve tu buka, jadi nisbah bahan api dan udara jadi tak betul la. maka, tu yang ja...
Post a Comment
Read more

HONDA RS150 IACV: IACV PROBLEM? RPM NAIK TINGGI BILA HIDUPKAN ENJIN?

 Hi semua, Salam sejahtera Masalah IACV saya berlaku selepas isu TPS wujud di milage 24000+km..kemungkinan kedua2nya ini saling berkait. Masalah IACV hadir ketika saya on the way balik semula ke Johor, ketika bahan bakar berkurang dari tangki moto. SIMPTOM  ? bila hidupkan enjin honda RS150 saya, RPM akan naik tinggi dan kadang2 sukar dikawal. tengah jalan pun, jika stop di trafik light, rpm akan naik tinggi dan mengaum bising..so, isu ni biasanya disebabkan IACV IACV APA TU IACV? IACV bermaksud Idle Air Control Valve. bahasa mudahnya nak control udara masuk ke ruang pembakaran sewaktu motosikal kita idle (tanpa pulas pendikit atau throttle) iaitu semasa tak bergerak. FUngsi dia mcm choke la pada motor lama yg guna karburator supaya moto mudah di hidupkan dan dalam masa sama injap dikawal dan dikecilkan bila enjin motosikal telah panas. IACV idling control valve (anak panah, lubang udara yang dikawal) APA FUNGSI IACV? Jika kita dah pulas throttle, IACV dah tak digunakan dan va...
4 comments
Read more

KENWOOD PROSPERO KM280 NOT WORKING..WHY?

Hi, Peace upon you all. This afternoon, my wife's food processor Kenwood km280 suddenly dead..she planned to prepare Dorayaki for us all, to eat in the evening. Fig 1: Kenwood KM280 mixer/food processor Unfortunately, after pours mix all the ingredient into the bowl, switch On the main plug and adjust switch knob to no 1 speed, nothing happens. After many tried, after referring to the manual that comes with this food processor (KM280), she gives up and asks me to do something about it. The first step to troubleshoot the problem is to check the power from the main plug and also the fuse. The outcomes are all well and working fine. Second, check the internal connection and gearing, visually. the reason is to make sure no visible damage to the cable and gearing. This will require disassembly of the top cover. It can be done by removing six screws under. after top cover is removed, internal circuits, motor, and gears (figure below) can be observed for any damage. Fortunate...
53 comments
Read more