Diagnostic Procedure

WARNING: This page is about a different car, the 2017 Mazda 3. However, it is still accessible from the selected car via links, so may be relevant.

FUEL GAUGE READING IS NOT CORRECT (INSTRUMENT CLUSTER) - DIAGNOSTIC PROCEDURE

Step	Inspection		Action
1	PERFORM CAN MALFUNCTION DIAGNOSIS AND DTC INSPECTION Perform the CAN malfunction diagnosis according to the recommendation of FOREWORD [INSTRUMENT CLUSTER]malfunction diagnosis, and if there is no CAN malfunction, perform inspection for DTCs. (See DTC INSPECTION [INSTRUMENT CLUSTER] .) Is the DTC displayed?	Yes	Go to the applicable DTC inspection. (See DTC TABLE [INSTRUMENT CLUSTER] .)
1		No	Go to the next step.
2	INSPECTION OF INSTRUMENT CLUSTER Perform inspection of the fuel gauge/LCD display referring to the instrument cluster inspection. (See INSTRUMENT CLUSTER INSPECTION .) Is the display normal?	Yes	Go to the next step.
2		No	Replace the instrument cluster. (See INSTRUMENT CLUSTER REMOVAL/INSTALLATION .)
3	DETERMINE IF MALFUNCTION CAUSE IS FUEL GAUGE SENDER Display the following rear body control module (RBCM) PIDs using the M-MDS. FUEL_SEN_M Verify the voltage in the display monitor while shaking the vehicle. Does the voltage change?	Yes	Go to the next step.
3		No	Go to Step 5.
4	DETERMINE IF MALFUNCTION CAUSE IS REAR BODY CONTROL MODULE (RBCM) Display the following instrument cluster PIDs using the M-MDS. FUEL_SEN_M Verify the resistance in the display monitor while shaking the vehicle. Does the resistance change?	Yes	Replace the instrument cluster. (See INSTRUMENT CLUSTER REMOVAL/INSTALLATION .)
4		No	Replace the rear body control module (RBCM). (See REAR BODY CONTROL MODULE (RBCM) REMOVAL/INSTALLATION .)
5	INSPECT FUEL GAUGE SENDER UNIT Switch the ignition off. Inspect the fuel gauge sender unit. (See FUEL GAUGE SENDER UNIT INSPECTION .) Is the fuel gauge sender unit normal?	Yes	Refer to the wiring diagram and verify whether or not there is a common connector between the fuel gauge sender unit and the rear body control module (RBCM). 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 mid-wiring harness for a short to power supply. Repair or replace the wiring harness which has a malfunction. If there is no common connector: Repair or replace the wiring harness which has a malfunction.
5		No	Replace the fuel gauge sender unit. (See FUEL GAUGE SENDER UNIT REMOVAL/INSTALLATION .)