Opel Sintra P1629 Engine Trouble Code
What is Opel Sintra P1629?
When Opel Sintra P1629 code appears, first check your gas cap. Pull over safely, ensure it is tight, and inspect for cracks. A loose or damaged gas cap affects fuel-system pressure and emissions. A replacement cap costs about $3–$10. This simple fix can resolve the code and improve fuel economy.
P1629 on the Opel Sintra
In cold climates, Opel Sintra vehicles frequently log P1629 during the first winter of ownership. Condensation inside the throttle body creates a temporary short circuit in the position sensor wiring, which clears once the engine warms up — but the fault code remains stored.
Code Information
| Code Type: | OBD-II Powertrain (P) Trouble Code |
| System: | Powertrain |
| Vehicle: | Opel Sintra |
| Brand: | Opel |
| Model: | Sintra |
| Code: | P1629 |
P1629 Opel Sintra Symptoms
Check Engine Light
Illuminated Opel Sintra dashboard warning
Engine Stalling
Engine stops unexpectedly or misfires
Performance Issues
Reduced power or acceleration on the Opel Sintra
Starting Problems
Difficulty starting the engine
Poor Fuel Economy
Increased fuel consumption on the Opel Sintra
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 Opel Sintra P1629
Diagnostic Steps:
Oxygen sensors measure exhaust gas oxygen content to optimise air-fuel ratio. This optimisation improves fuel economy and reduces emissions. Sensors degrade over time and require periodic replacement.
Repair Solution:
Firing order is engineered to minimise vibration. Altering firing order results in mistimed ignition and poor engine operation. Consult vehicle-specific repair manual for correct firing order.
Technical Notes:
P1629 on electronically controlled automatic transmissions relates to shift solenoid operation. The solenoid actuates hydraulic circuits controlling clutches or bands for gear changes.
Opel Sintra P1629 Repair Cost
For Opel Sintra diesel variants with swirl flap actuator failure causing P1629, the repair ranges from $180 (actuator only) to $900+ if a broken flap has been ingested by the engine. Early intervention is strongly recommended.
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 Opel Sintra
On the Opel Sintra, the VANOS (variable camshaft timing) solenoid is routinely replaced for P1629 when the actual issue is oil pressure insufficiency. No solenoid will operate correctly if the oil pressure required to actuate the VVT phaser is not present.
DIY Repair Guide: P1629 on Opel Sintra
The coolant temperature sensor on the Opel Sintra is a straightforward DIY item (difficulty 2/5). Have a drain tray ready for the small amount of coolant that spills when the sensor is removed. Top up the cooling system afterwards and check for air pockets.
Preventing P1629 on the Opel Sintra
For diesel Opel Sintra owners, a DPF (Diesel Particulate Filter) regeneration run on the motorway every 500 miles prevents soot blockage that back-pressures the exhaust and forces P1629 flags via the pressure differential sensors.
Frequently Asked Questions — Opel Sintra P1629
A: P1629 is a standardised OBD-II code that can appear on any make and model. However, the specific components and circuits that trigger this code, and the repair procedures involved, vary significantly between vehicles. The information on this page is focused on the Opel Sintra.