Start problems and lack of traction in PSA 1.6 HDI engines?

You might know someone, maybe it’s even yourself, who has speculated about the cause of starting problems, lack of traction or increasing smoke in vehicles with a PSA 1.6 HDI engine? Then read on, to find some useful information.

For many, it is nothing new that for PSA vehicles with this type of engine starting in 2004, there are several points to be taken into account both before and after replacing the EGR valve.

A small check up that can be of great importance.
If the above symptoms and possible storage of the P0400 and / or P0100 DTCs are detected, it is advisable to check the throttle valve of the intake manifold before initiating EGR valve fault detection. “The position of the throttle valve is controlled by a small arm and it is not uncommon for the arm to fall off, closing the throttle valve and blocking the air supply to the engine," says Product Coordinator Lars Berthelsen, adding: "However, in some cases the symptoms may be due to a faulty airflow meter. My experience is that in many cases error codes generated by the air flow meter are not stored/recognized, in which case it is recommended to test the air flow meter".

DTC P0400: EGR flow malfunction 
DTC P0100: Air flow meter, circuit malfunction


You might know someone, maybe it’s even yourself, who has speculated about the cause of starting problems, lack of traction or increasing smoke in vehicles with a PSA 1.6 HDI engine? 

Need to adjust EGR valve
If both the throttle valve and the air flow meter are working properly, it may be necessary to replace the EGR valve. When replacing the EGR valve, the EGR valve must be adapted using a diagnostic tester. Failure to adapt the EGR valve will result in uneven engine running. In addition, it results in an extremely limited life span of the EGR valve and oftentimes the valve will be damaged.
"We've seen several examples of valves that were damaged after driving just a few miles, typically it's the head of the valve that falls off, because the lack of adjustment causes the valve to operate under extremely high pressure," explains Lars Berthelsen: "If you have problems with the calibration of the new valve, we recommend the use of pass-thru diagnostic devices with regard to an engine management update".

Error codes P0409, P0490, P1459 indicate a defective EGR valve. If the EGR system can not be adjusted after replacement, this may indicate a faulty engine control unit. The only solution to the problem is replacing or repairing the engine control unit.

DTC P0409: EGR sensor A circuit 
DTC P0490: EGR signal too high
DTC P1459: Position indicator of the EGR valve. The valve is blocked in open condition while driving (Evap incorrect work flow)

EGR valve 881310010
 

Severe sooting of the EGR-valve
Experience has shown that the EGR valve is often exposed to a particularly strong sooting in this type of engine. In connection with the replacement of the EGR valve we therefore recommend to evaluate the diesel particulate filter of the vehicle. An older particulate filter, which has traveled many kilometers, regenerates more frequently, which considerably increases the load on the EGR valve.

We also recommend using diesel additives continuously. The use of additives protects fuel systems and combustion chambers from soot deposits.

Always use additives according to the manufacturer's instructions.