2012 Mazda CX-7 FWD L4-2.5LFACTORY OEM SERVICE PROCEDURE

Component Tests and General Diagnostics





PCM INSPECTION [L5]

Using M-MDS

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

- CMP sensor
- Main relay

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

Factory service manual diagram





2. Turn the ignition switch to the ON position.

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, 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
With cruise control system

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

Without Using the M-MDS

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.

PCM inspection preparation

1. Disconnect the negative battery cable.

2. Remove the battery and battery tray. Removal and Replacement

3. Remove the windshield wiper arm and blade. (See Windshield Wiper Arm And Blade Removal/Installation.)

4. Remove the cowl grille. (See Cowl Grille Removal/Installation.)

5. Remove the windshield wiper motor. (See Windshield Washer Motor Removal/Installation.)

6. Remove the cowl panel. (See Cowl Panel Removal/Installation.)

7. Remove the PCM bracket with the PCM connector still connected. (See Service and Repair.)

8. Install the battery and battery tray. Removal and Replacement

9. Connect the negative battery cable.

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




Factory service manual diagram




*1
With cruise control system

Inspection Using An Oscilloscope (Reference)

Cooling fan control

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

APP sensor No.2 signal

Accelerator pedal released

Factory service manual diagram




Accelerator pedal depressed

Factory service manual diagram





PCM terminals
- 1AO(+)-body ground(-)

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

Vehicle condition
- Turn the ignition switch to the ON position.

Purge control

Factory service manual diagram




PCM terminals
- 1BA(+)-body ground(-)

Oscilloscope setting
- 10 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)

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

IGT1, IGT2, IGT3, IGT4 control

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

CMP 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 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

Generator field coil control

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

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 (#1, #2, #3, #4) 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.

Rather have a pro handle this?

A certified mobile mechanic comes to your home or office. They bring the tools, you stay comfortable. No tow truck, no waiting room, no surprises.

Comes to youSame-day available12-month warranty
Get a Free Quote

No obligation. See pricing before you book.