No. 2 Check Engine Light Illuminates

2	CHECK ENGINE LIGHT ILLUMINATES
DESCRIPTION	Check engine light illuminates incorrectly. NOTE: If there is a malfunction in the engine system, the PCM stores a DTC and illuminates the check engine light.
Possible cause	Check engine light illuminates for emission-related concern (DTC is stored in PCM) Short to ground in wiring harness between the following terminals: Instrument cluster terminal B-BCM terminal 2D Instrument cluster terminal D-BCM terminal 2C BCM terminal 3C-PCM terminal 2AK BCM terminal 3D-PCM terminal 2AL Open circuit in wiring harness between the following terminals: Instrument cluster terminal B-BCM terminal 2D Instrument cluster terminal D-BCM terminal 2C BCM terminal 3C-PCM terminal 2AK BCM terminal 3D-PCM terminal 2AL Instrument cluster malfunction

CHECK ENGINE LIGHT ILLUMINATES

DESCRIPTION

Check engine light illuminates incorrectly.

NOTE:

If there is a malfunction in the engine system, the PCM stores a DTC and illuminates the check engine light.

Possible cause

Check engine light illuminates for emission-related concern (DTC is stored in PCM)
Short to ground in wiring harness between the following terminals:
- Instrument cluster terminal B-BCM terminal 2D
- Instrument cluster terminal D-BCM terminal 2C
- BCM terminal 3C-PCM terminal 2AK
- BCM terminal 3D-PCM terminal 2AL
Open circuit in wiring harness between the following terminals:
- Instrument cluster terminal B-BCM terminal 2D
- Instrument cluster terminal D-BCM terminal 2C
- BCM terminal 3C-PCM terminal 2AK
- BCM terminal 3D-PCM terminal 2AL
Instrument cluster malfunction

Fig 1: Instrument Cluster - Circuit Diagram

Courtesy of MAZDA MOTORS CORP.

Diagnostic Procedure

Step	INSPECTION	RESULTS	Action
1	VERIFY PCM DTC Retrieve any DTCs using the M-MDS. (See ON-BOARD DIAGNOSTIC TEST ). Are any DTCs present?	Yes	Go to the applicable DTC inspection. (See DTC TABLE (PCM (SKYACTIV-G2.0)) ).
1		No	Go to the next step.
2	INSPECT COMMUNICATION LINE BETWEEN PCM AND INSTRUMENT CLUSTER Inspect for a short or open circuit between the following terminals: Instrument cluster terminal B-BCM terminal 2D Instrument cluster terminal D-BCM terminal 2C BCM terminal 3C-PCM terminal 2AK BCM terminal 3D- PCM terminal 2AL Is the wiring harness normal?	Yes	Inspect the instrument cluster. (See INSTRUMENT CLUSTER INSPECTION ). If there is any malfunction: Repair or replace the malfunctioning part according to the inspection results, then go to the next step. (See INSTRUMENT CLUSTER REMOVAL/INSTALLATION ).
2		No	Refer to the wiring diagram and verify whether or not there is a common connector between the following terminals: Instrument cluster terminal B-BCM terminal 2D Instrument cluster terminal D-BCM terminal 2C BCM terminal 3C-PCM terminal 2AK BCM terminal 3D-PCM terminal 2AL If there is a common connector: Determine the malfunctioning part by inspecting the common connector and the terminal for corrosion, damage, or pin disconnection, and the common wiring harness for a short to ground or open circuit. Repair or replace the malfunctioning part. If there is no common connector: Repair or replace the wiring harness which has a short to ground or open circuit.
3	Verify the test results. If normal, return to the diagnostic index to service any additional symptoms. (See SYMPTOM DIAGNOSTIC INDEX ). If the malfunction remains, inspect the related Service Bulletins and/or On -line Repair Information and perform repair or diagnosis. If the vehicle is repaired, troubleshooting is completed. If the vehicle is not repaired or additional diagnostic information is not available, reprogram the PCM if a later calibration is available. Retest.