Nissan Exa P1629 Engine Trouble Code
What is Nissan Exa P1629?
With Nissan Exa P1629, you may drive for several weeks with a malfunctioning MAF sensor, but expect decreased fuel economy and eventual stalling. Shop replacement costs $240–$400 depending on vehicle. The labour is straightforward, with most cost from the part itself.
P1629 on the Nissan Exa
A known issue on the Nissan Exa is that aftermarket air filter upgrades can inadvertently trigger P1629. High-flow filters alter the intake resonance frequency, causing the MAP sensor to report pressure readings outside factory calibration.
Code Information
| Code Type: | OBD-II Powertrain (P) Trouble Code |
| System: | Powertrain |
| Vehicle: | Nissan Exa |
| Brand: | Nissan |
| Model: | Exa |
| Code: | P1629 |
P1629 Nissan Exa Symptoms
Check Engine Light
Illuminated Nissan Exa dashboard warning
Engine Stalling
Engine stops unexpectedly or misfires
Performance Issues
Reduced power or acceleration on the Nissan Exa
Starting Problems
Difficulty starting the engine
Poor Fuel Economy
Increased fuel consumption on the Nissan Exa
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 Nissan Exa P1629
Diagnostic Steps:
Poor running symptoms align with MAP sensor malfunction. In some cases, a faulty MAP sensor will not trigger a code. The issue may represent separate wiring concerns requiring individual diagnosis.
Repair Solution:
Power steering pressure switch monitors system operation. If pressure changes are not detected after calibrated speed transitions, this DTC sets. Verify PSP switch operation and check for circuit opens or shorts.
Technical Notes:
P1629 DTCs can be triggered by upstream issues. For example, a dirty MAF sensor may cause incorrect fuel-trim adjustments, leading oxygen sensors to report mixture problems. Address root causes first.
Nissan Exa P1629 Repair Cost
ECU software update for the Nissan Exa to resolve the P1629 calibration bug is performed free of charge at a franchised Nissan dealer under the technical service bulletin programme. Always confirm the ECU part number and current flash version before spending money on sensors.
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 Nissan Exa
When P1629 triggers on the Nissan Exa, 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 Nissan Exa
Clearing P1629 on your Nissan Exa 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 Nissan Exa
On the Nissan Exa, using a quality fuel system cleaner (added to the fuel tank every 10,000 miles) helps prevent injector deposit build-up that indirectly triggers P1629 through fuel-trim imbalances.
Frequently Asked Questions — Nissan Exa P1629
A: It depends on the severity. If the check-engine light is steady, it is generally safe to drive to a workshop within the next few days. If the light is flashing, pull over safely as soon as possible — a flashing light indicates an active misfire that can cause expensive catalytic converter damage within minutes.