2012 Mazda 6 L4-2.5LFACTORY OEM SERVICE PROCEDURE

Component Tests and General Diagnostics





PCM INSPECTION [MZR 2.5]

Using M-MDS

NOTE:
- PIDs for the following parts are not available on this model. Go to the appropriate part inspection.

- CMP sensor
- Main relay

1. Connect the M-MDS to the DLC-2.

Factory service manual diagram





2. Switch the ignition to ON.

3. Measure the PID value.

- If PID value is not within the specification, follow the instructions in Action column.

NOTE:
- The PID/DATA MONITOR function monitors the calculated value of the input/output signals in the PCM. Therefore, an output device malfunction is not directly indicated as a malfunction of the monitored value for the output device. If a monitored value of an output device is out of specification, inspect the monitored value of the input device related to the output control.
- For input/output signals except those of the monitoring items, use a voltmeter to measure the PCM terminal voltage.
- The simulation items that are used in the ENGINE CONTROL SYSTEM OPERATION INSPECTION are as follows.

- ACCS, ALTF, ARPMDES, EVAPCP, EVAPCV, FAN_DUTY, FP, HTR11, IMRC, IMTV, INJ_1~4, SEGRP, Test, VT Duty1 wt

PID/DATA monitor table (reference)

Factory service manual diagram




Factory service manual diagram




Factory service manual diagram




Factory service manual diagram




Factory service manual diagram




Factory service manual diagram




Factory service manual diagram




*1
Calculated value; differs from terminal voltage
*2
MTX
*3
Vehicles equipped with cruise control switch

- Following PIDs are for the ATX models. If inspects for following PIDs, PID/Data Monitor Inspection

Without Using the SST

CAUTION:
- The PCM terminal voltages vary with change in measuring conditions and vehicle conditions. Always carry out a total inspection of the input systems, output systems, and PCM to determine the cause of trouble. Otherwise, a wrong diagnosis will be made.

1. Measure the voltage at each terminal.

- If any incorrect voltage is detected, inspect the related system(s), wiring harnesses and connector(s) referring to the Action column in the terminal voltage table.

Terminal voltage table (Reference)

Factory service manual diagram




Factory service manual diagram




Factory service manual diagram




Factory service manual diagram




Factory service manual diagram




Factory service manual diagram




Factory service manual diagram




Factory service manual diagram




*1
Vehicles equipped with cruise control switch
*2
Without advanced keyless entry and push button start system
*3
With advanced keyless entry and push button start system
*4
MTX
*5
ATX

Inspection Using An Oscilloscope (Reference)

Fan control module signal

Factory service manual diagram




PCM terminals
- 1R-body ground(-)

Oscilloscope setting
- 5 V/DIV (Y), 20 ms/DIV (X), DC range

Vehicle condition
- Idle (after warm up)

A/F sensor heater control

Factory service manual diagram




PCM terminals
- 2A(+)-body ground(-)

Oscilloscope setting
- 5 V/DIV (Y), 200 ms/DIV (X), DC range

Vehicle condition
- Idle (immediately after starting the engine)

HO2S heater control

Factory service manual diagram




PCM terminals
- 2B(+)-body ground(-)

Oscilloscope setting
- 5 V/DIV (Y), 1 s/DIV (X), DC range

Vehicle condition
- Idle (immediately after starting the engine)

Purge control signal

Factory service manual diagram




PCM terminals
- 2C(+)-body ground(-)

Oscilloscope setting
- 10 V/DIV (Y), 20 ms/DIV (X), DC range

Vehicle condition
- Idle (after warm up)

OCV control signal

Factory service manual diagram




PCM terminals
- 2E(+)-body ground(-)

Oscilloscope setting
- 2 V/DIV (Y), 0.8 ms/DIV (X), DC range

Vehicle condition
- Idle (after warm up)

CMP sensor signal

Factory service manual diagram




PCM terminals
- 2S(+)-body ground(-)

Oscilloscope setting
- 1 V/DIV (Y), 25 ms/DIV (X), DC range

Vehicle condition
- Idle (after warm up)

CKP sensor signal

Factory service manual diagram




PCM terminals
- 2W(+)-body ground(-)

Oscilloscope setting
- 1 V/DIV (Y), 5 ms/DIV (X), DC range

Vehicle condition
- Idle (after warm up)

IGT1, IGT2, IGT3, IGT4 control signals

Factory service manual diagram




PCM terminals
- IGT1(ignition coil No.1): 2G(+)-body ground(-)
- IGT2(ignition coil No.2): 2K(+)-body ground(-)
- IGT3(ignition coil No.3): 2L(+)-body ground(-)
- IGT4(ignition coil No.4): 2H(+)-body ground(-)

Oscilloscope setting
- 1 V/DIV (Y), 50 ms/DIV (X), DC range

Vehicle condition
- Idle (after warm up)

Generator field coil control signal

Factory service manual diagram




PCM terminals
- 2AA(+)-body ground(-)

Oscilloscope setting
- 0.5 V/DIV (Y), 2 ms/DIV (X), DC range

Vehicle condition
- Idle (after warm up)

Generator output voltage signal

Factory service manual diagram




PCM terminals
- 2AF(+)-body ground(-)

Oscilloscope setting
- 2 V/DIV (Y), 2 ms/DIV (X), DC range

Vehicle condition
- Idle (after warm up)

Fuel injection control

Factory service manual diagram




PCM terminals
- Fuel Injection No.1: 2BB(+)-body ground(-)
- Fuel Injection No.2: 2BC(+)-body ground(-)
- Fuel Injection No.3: 2BD(+)-body ground(-)
- Fuel Injection No.4: 2AZ(+)-body ground(-)

Oscilloscope setting
- 10 V/DIV (Y), 25 ms/DIV (X), DC range

Vehicle condition
- Idle (after warm up)

Factory Service Tools

Use the Manual With the Right Hardware

Pair factory procedures with proven DIY tools so the instructions are easier to execute.

Disclosure: Verified tool recommendations may earn an affiliate commission at no cost to you.

When to See a Mechanic

Stop DIY work and contact a certified mechanic immediately if any of the following apply:

  • β€’ You smell fuel, burning insulation, or see smoke.
  • β€’ Brakes feel soft, pull hard to one side, or make grinding noises.
  • β€’ The engine overheats, stalls repeatedly, or misfires under load.
  • β€’ You are missing required tools, torque specs, or safe lifting equipment.
  • β€’ You are not confident in the next step or safety outcome.