Toyota Century P1629 Engine Trouble Code
What is Toyota Century P1629?
When Toyota Century 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 Toyota Century
The Toyota Century has a known weak point in the lambda sensor wiring loom where it passes through the floor pan grommet. Road salt and vibration cause the insulation to crack at this point, creating an intermittent open circuit that stores P1629 without a consistent symptom.
Code Information
| Code Type: | OBD-II Powertrain (P) Trouble Code |
| System: | Powertrain |
| Vehicle: | Toyota Century |
| Brand: | Toyota |
| Model: | Century |
| Code: | P1629 |
P1629 Toyota Century Symptoms
Check Engine Light
Illuminated Toyota Century dashboard warning
Engine Stalling
Engine stops unexpectedly or misfires
Performance Issues
Reduced power or acceleration on the Toyota Century
Starting Problems
Difficulty starting the engine
Poor Fuel Economy
Increased fuel consumption on the Toyota Century
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 Toyota Century 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:
Brake switch circuit concerns may involve open or shorted BPP circuits, damaged switches, or misadjustment. Verify stoplight function and follow proper self-test procedures per service manual.
Technical Notes:
P1629 DTC indicating a sensor fault does not always mean the sensor itself is bad. The issue may stem from the systems being monitored or even the sensor wiring. Proper diagnosis is essential.
Toyota Century P1629 Repair Cost
Crankshaft reluctor ring inspection and replacement on the Toyota Century is a major service item costing $600–$1,100. Given the labour required to access the component, it is advisable to replace the rear crankshaft seal and crankshaft position sensor simultaneously while the area is open.
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 Toyota Century
When Toyota Century presents P1629 with a concurrent coolant temperature DTC, technicians sometimes replace the thermostat rather than the coolant temperature sensor (CTS). The CTS is a $15–$25 component; the thermostat job carries 1–2 hours of additional labour.
DIY Repair Guide: P1629 on Toyota Century
Clearing P1629 on your Toyota Century 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 Toyota Century
Ensure the Toyota Century oil cap and dipstick tube seal are airtight. Even a small crank-case vacuum leak can cause the PCM to log P1629 and, over time, allows moisture-laden air to degrade the engine oil faster than the scheduled service interval.
Frequently Asked Questions — Toyota Century P1629
A: Almost certainly yes. Most faults that trigger P1629 cause the ECU to operate in open-loop mode or apply overly rich fuel trims, both of which increase fuel consumption by 5–15%. Resolving the fault promptly pays for itself in fuel savings over time.