Renault Scenic P1629 Engine Trouble Code
What is Renault Scenic P1629?
Renault Scenic P1629 indicates potential catalytic converter failure. If completely failed, your vehicle may not run properly and fuel economy will suffer significantly. Average replacement cost is $2,000–$2,140. This repair requires professional service and should not be delayed.
P1629 on the Renault Scenic
The Renault Scenic is particularly susceptible to P1629 faults when the engine management unit receives conflicting sensor data. Owners report that P1629 on Renault Scenic most commonly surfaces after 60,000 miles, especially when routine service intervals have been missed.
Code Information
| Code Type: | OBD-II Powertrain (P) Trouble Code |
| System: | Powertrain |
| Vehicle: | Renault Scenic |
| Brand: | Renault |
| Model: | Scenic |
| Code: | P1629 |
P1629 Renault Scenic Symptoms
Check Engine Light
Illuminated Renault Scenic dashboard warning
Engine Stalling
Engine stops unexpectedly or misfires
Performance Issues
Reduced power or acceleration on the Renault Scenic
Starting Problems
Difficulty starting the engine
Poor Fuel Economy
Increased fuel consumption on the Renault Scenic
Increased Emissions
Failed emissions test due to P1629
P1629 Code Structure
Understanding what each digit means in the P1629 powertrain trouble code:
| P | 1 | 6 | 2 | 9 |
|---|---|---|---|---|
| Powertrain Code | Fuel And Air Metering | Fuel Temperature Sensor B Circuit Range/Performance | Turbocharger Boost Sensor A Circuit Low | Reverse Input Circuit |
How to Fix Renault Scenic P1629
Diagnostic Steps:
The catalytic converter has oxygen sensors before and after it. When warm and in closed-loop mode, the upstream O2 sensor reading should fluctuate, while downstream should remain steady.
Repair Solution:
Disconnected, dirty, or fouled spark plugs commonly prevent proper engine operation. Replace spark plugs every season or 25 hours. Verify proper spark plug gap. If plugs are good, check ignition components: spark plug wires, coils, and ignition module.
Technical Notes:
Parts or components should not be replaced based solely on P1629 DTC. Consult your vehicle service manual for proper diagnostic procedures, possible causes, and required testing before replacement.
Renault Scenic P1629 Repair Cost
PCV system overhaul on the Renault Scenic — which resolves oil-mist contamination of the MAF sensor — costs $100–$200. The MAF sensor should be cleaned ($15–$25 DIY) or replaced ($80–$150) at the same time to ensure accurate fuelling after the fix.
P1629 Description
P1629 engine trouble code is related to Reverse Input Circuit.
Main Cause
The primary reason for P1629 OBD-II Engine Trouble Code is: Fuel Temperature Sensor B Circuit Range/Performance.
Common P1629 Misdiagnosis on the Renault Scenic
When P1629 triggers on the Renault Scenic, a flashing check-engine light (as opposed to a steady one) indicates an active misfire. Misfire codes are commonly misdiagnosed as sensor faults; always rule out ignition and fuel delivery issues before testing sensors.
DIY Repair Guide: P1629 on Renault Scenic
Clearing P1629 on your Renault Scenic with a basic OBD-II reader ($20–$40) is straightforward: plug the reader into the diagnostic port under the dashboard, read the stored code, and clear it. If it returns within one drive cycle, the underlying fault is still present and requires attention.
Preventing P1629 on the Renault Scenic
The Renault Scenic EVAP system requires the fuel tank breather hoses to be flexible and crack-free. A visual inspection at every oil change prevents the slow vacuum leak that triggers P1629 without any drivability symptom.
Frequently Asked Questions — Renault Scenic P1629
A: Yes. A weak battery causes voltage drop during cranking that confuses the ECU and can store a range of fault codes. Always rule out battery and charging system health before diagnosing sensor-related codes.