Applicable Models:
2004-’07 Mazda3
2005-’07 Mazda6
2006-’07 MX-5 vehicles
During service/removal of fuel system parts on the above vehicles, the memory of the malfunctions and the long-term fuel trim need to be cleared by either removing the fuse for the PCM or disconnecting the negative battery cable for at least 60 seconds. If not, the old memory remains, which affects driveability and the diagnostic system.
The fuse for the PCM is the ENG +B fuse on Mazda3 and Mazda6 models and the ROOM fuse on MX-5 models in the engine compartment fuse block.
The above actions are required for the following:
1. When servicing/replacing a fuel system part.
2. When the vehicle experienced an MIL coming on with DTC P2177, P2178, P2187, P2188, P0171 and/or P0172 stored in memory.
Previously, the workshop manual for each relevant DTC section mentioned “Clear the DTC from PCM memory using the M-MDS.” This has been updated.
Note: The radio presets and clock will need to be set on Mazda3 and Mazda6 models and both front power windows will need to be initialized on Mazda6 models if the negative battery cable is disconnected. This does not have to be done if the fuse is removed. On MX-5 models, the radio presets and clock will need to be set and the steering angle sensor will need to be initialized if either the negative battery cable is disconnected or the fuse is removed. See the Steering Angle Sensor Initialization Procedure in the workshop manual.
