B1938 Renault Master 2 Diagnostic Trouble Code

B1938 Renault Master 2 code definition:
B1938 is a kind of OBD-II Diagnostic B-Body Diagnostic Trouble Code for Renault Master 2.

B1938 Renault Master 2 is triggered when the bank 1 camshaft position sensor doesn't match the signal from the crankshaft position sensor. Other symptoms that may indicate this problem are when the Check Engine Light illuminates and when there is a visible lack of engine power.

Symptoms

Symptoms of a B1938 Renault Master 2 diagnostic trouble code may include:

Rich or lean exhaust
Fuel pressure too low
Engine surge
The light may stay on or light intermittently as the DPF regenerates. The engine will be sluggish on acceleration.

Possible Causes :

An air leak forward of the DPF will change the sensor readings resulting in the code
Rusty exhaust systems, cracked exhaust manifolds or damaged or missing gaskets or donuts will cause air leaks.
Faulty IMRC actuator relay (if equipped)

Common Misdiagnoses

TP Sensor Learn Not Complete Problem
Low Coolant Circuit Problem
Cruise Control System - Vehicle Accel Too High Problem
TFP Valve Position Switch-Drive Without Drive Ratio Problem
Problem

Repair Processes :

If you find a related TSB, the information will often help in diagnosing the code in question as TSBs are crested from many thousands of repairs. Look for missing ground strap or a rusty ground where the fuel tank is grounded to the frame. Check for damage to the wiring harness connector. Replace the oxygen sensor that is downstream from the catalytic converter on the side of the engine that does not contain cylinder #1. Also, if a oxygen sensor code stating "heater circuit malfunction" the sensor has most probably failed.

Process Tips

Diagnostic trouble code B1938 Renault Master 2 is not difficult to diagnose and repair. Thus, it always pays to have a qualified technician to look after your vehicle should this error code arise.

Diagnosing this code requires the engine to be in good running shape, without unmetered air entering the engine. If other codes that relates to misfiring condition, lean running or air entering the engine is present, then you must first fix those error codes before B1938 Renault Master 2.

Fortunately, B1938 Renault Master 2 is a fairly common OBD code, meaning that it applies to all makes and models of vehicles made after 1996.