P1521 - FAULT CODE - OBD2

P1521 Code failures by brands

P1521 CHRYSLER, DODGE, JEEP, RAM: INCORRECT ENGINE OIL TYPE

Description of DTC code P1521

The PCM (Powertrain Control Module) checks the right performance of the engine. This module monitors the viscosity of the oil, an important component used to lubricate the various moving parts of the engine, and it reduces the degrees of friction between metals, giving them a longer life.

The PCM relies on oil temperature, oil pressure, and other vital engine input signals to verify that the oil viscosity is right. In case the oil viscosity is not right, the MDS (Multiple Displacement System) operation will be affected by delaying cylinder activation.

The P1521 OBDII diagnostic code occurs after the PCM detects that the engine oil viscosity is not correct.

Symptoms of fault code P1521

Check Engine light ON.

Causes of OBD2 P1521

The P1521 OBD2 fault code is stored for one of the following reasons:

The viscosity of the engine oil may not be the required one.
The type of oil supplied to the engine may not be correct.
The engine may have contamination levels in the oil.
The Engine Oil Pressure Sensor may be in poor condition.
The Powertrain Control Module may have programming errors.

Possible solutions of the DTC code P1521

Steps to solve the P1521 OBDII DTC:

To begin the diagnosis, it is necessary to verify that the oil supplied to the engine meets the viscosity specified in the service manual.
Check with an automotive scanner to know if other fault codes are set, especially those that point to problems with the Engine Oil Pressure Sensor. Diagnose those codes.
Check that there are no traces of contamination in the engine oil. If you discover a dark color, maybe the oil is polluted, replace it.