Diagnostic Procedure

WARNING: This page is about a different car, the 2020 Mazda CX-30. However, it is still accessible from the selected car via links, so may be relevant.

When performing an asterisked (*) troubleshooting inspection, shake the wiring harness and connectors while performing the inspection to discover whether poor contact points are the cause of any intermittent malfunctions. If there is a problem, check to make sure connectors, terminals and wiring harnesses are connected correctly and undamaged.

HEATED STEERING WHEEL SYSTEM OPERATES CONSTANTLY [HEATED STEERING WHEEL] DIAGNOSTIC PROCEDURE

Step	Inspection	Results	Action
1	DETERMINE IF THE MALFUNCTION CAUSE IS THE HEATED STEERING WHEEL SWITCH Switch the ignition off. Disconnect the climate control unit connector. (See CLIMATE CONTROL UNIT REMOVAL/INSTALLATION [FULL-AUTO AIR CONDITIONER (US)] .) (See CLIMATE CONTROL UNIT REMOVAL/INSTALLATION [MANUAL AIR CONDITIONER (US)] .) Switch the ignition ON (engine off or on). Is the heated steering wheel system operating?	Yes	Go to the next step.
1		No	Replace the climate control unit and perform the repair completion verification. (See CLIMATE CONTROL UNIT REMOVAL/INSTALLATION [FULL-AUTO AIR CONDITIONER (US)] .) (See CLIMATE CONTROL UNIT REMOVAL/INSTALLATION [MANUAL AIR CONDITIONER (US)] .)
2*	INSPECT CLOCK SPRING CONTROL CIRCUIT FOR OPEN CIRCUIT WARNING: Handling the component parts improperly can accidentally operate (deploy) the air bag module, which may seriously injure you. Read the service warnings/cautions and the workshop service information before handling the air bag system components. (See AIR BAG SYSTEM SERVICE WARNINGS [TWO-STEP DEPLOYMENT CONTROL SYSTEM - US/CANADA SPEC.] .) (See AIR BAG SYSTEM SERVICE CAUTIONS [TWO-STEP DEPLOYMENT CONTROL SYSTEM - US/CANADA SPEC.] .) Switch the ignition off. Disconnect the negative battery terminal and wait for 1 min or more. (See NEGATIVE BATTERY TERMINAL DISCONNECTION/CONNECTION (US) .) Inspect the applicable circuit for an open circuit. (See CIRCUIT INSPECTION .) Is the circuit normal?	Yes	Go to the next step.
2*		No	Repair or replace the malfunctioning location and perform the repair completion verification.
3*	INSPECT CLOCK SPRING CONTROL CIRCUIT FOR SHORT TO GROUND Inspect the applicable circuit for a short to ground. (See CIRCUIT INSPECTION .) Is the circuit normal?	Yes	Go to the next step.
3*		No	Repair or replace the malfunctioning location and perform the repair completion verification.
4*	INSPECT CLOCK SPRING CONTROL CIRCUIT FOR SHORT TO POWER SUPPLY Inspect the applicable circuit for a short to power supply. See CIRCUIT INSPECTION .) Is the circuit normal?	Yes	Go to the next step.
4*		No	Repair or replace the malfunctioning location and perform the repair completion verification.
5*	INSPECT HEATED STEERING WHEEL CONTROL UNIT CONTROL CIRCUIT FOR OPEN CIRCUIT Inspect the applicable circuit for an open circuit. (See CIRCUIT INSPECTION .) Is the circuit normal?	Yes	Go to the next step.
5*		No	Repair or replace the malfunctioning location and perform the repair completion verification.
6*	INSPECT HEATED STEERING WHEEL CONTROL UNIT CONTROL CIRCUIT FOR SHORT TO GROUND Inspect the applicable circuit for a short to ground. (See CIRCUIT INSPECTION .) Is the circuit normal?	Yes	Go to the next step.
6*		No	Repair or replace the malfunctioning location and perform the repair completion verification.
7*	INSPECT HEATED STEERING WHEEL CONTROL UNIT CONTROL CIRCUIT FOR SHORT TO POWER SUPPLY Inspect the applicable circuit for a short to power supply. (See CIRCUIT INSPECTION .) Is the circuit normal?	Yes	Go to the next step.
7*		No	Repair or replace the malfunctioning location and perform the repair completion verification.
8*	DETERMINE IF CAUSE OF MALFUNCTION IS CLOCK SPRING Inspect for continuity between the following terminals: Clock spring connector terminal 4B and 5B Is there continuity?	Yes	Refer to the controller area network (CAN) malfunction diagnosis flow to inspect for a CAN communication error. (See CONTROLLER AREA NETWORK (CAN) MALFUNCTION DIAGNOSIS FLOW (US) .) If the CAN communication is normal, perform the diagnosis from Step 1. If the malfunction recurs, replace the climate control unit. (See CLIMATE CONTROL UNIT REMOVAL/INSTALLATION [FULL-AUTO AIR CONDITIONER (US)] .) (See CLIMATE CONTROL UNIT REMOVAL/INSTALLATION [MANUAL AIR CONDITIONER (US)] .)
8*		No	Replace the clock spring and perform the repair completion verification. (See CLOCK SPRING REMOVAL/INSTALLATION [TWO-STEP DEPLOYMENT CONTROL SYSTEM - US/CANADA SPEC.] .)
Repair completion verification	VERIFY IF MALFUNCTION CAUSE IS CORRECTED Always reconnect all disconnected connectors. Switch the ignition ON (engine off or on). Operate the heated steering wheel switch to turn on the heated steering wheel system. Does the heated steering wheel system operate normally?	Yes	Troubleshooting completed. (Explain the contents of the servicing to the customer.)
Repair completion verification		No	Verify the malfunction symptom in the symptom troubleshooting chart and perform the other applicable malfunction diagnosis. (See SYMPTOM TROUBLESHOOTING [HEATED STEERING WHEEL] .)