NO.1 STEERING WARMER SYSTEM DOES NOT OPERATE [STEERING WARMER]

Description

Steering warmer does not warm steering wheel even though steering warmer switch is on

Possible Causes

The power supply is not supplied to filament of steering warmer

• Open circuit in steering warmer control unit power supply circuit:

― Steering warmer control unit terminal D and battery positive terminal

• ST.HEATER 15 A fuse malfunction (Blown fuse):

― Short to ground in wiring harness between ST.HEATER 15 A fuse and steering warmer control unit terminal D

• C/U IG1 15 A fuse malfunction (Blown fuse):

― Short to ground in wiring harness between C/U IG1 15 A fuse and steering warmer relay

• IG1 relay and Steering warmer relay malfunction:

― Short to ground in wiring harness between IG1 relay and steering warmer relay

― Short to ground in wiring harness between steering warmer relay and steering warmer control unit terminal D

• Clock spring malfunction:

― Open circuit in wiring harness between clock spring connector 4A and 5A

• Poor connect the connector:

― Clock spring connector and steering warmer control unit connector

Steering warmer control unit not operation

• Open circuit in wiring harness between the following terminal:

― Steering warmer control unit terminal A and body ground

• Clock spring malfunction:

― Open circuit in wiring harness between clock spring connector 4B and 5B

Steering warmer unit cannot control filament on

• Steering warmer unit malfunction

Steering warmer filament does not generate heat

• Steering warmer unit malfunction

Steering warmer control unit cannot receive operation signal

• Steering warmer control unit malfunction

• Open circuit or short to ground in wiring harness between the following terminal:

― Steering warmer control unit terminal C and indicator unit terminal I

• Clock spring malfunction:

― Open circuit in wiring harness between clock spring connector 4D and 5D

• 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.

STEP	INSPECTION		ACTION
1	DETERMINE IF MALFUNCTION CAUSE IS STEERING WARMER SWITCH • Operate the steering warmer switch to turn on the steering warmer system. • Does the steering warmer switch LED illuminate?	Yes	Go to the next step.
1		No	Inspect the indicator unit, then go to step 14. (See INDICATOR UNIT INSPECTION.)
2	INSPECT IG1 RELAY • Inspect the IG1 relay. • Is the relay normal?	Yes	Go to the next step.
2		No	Inspect the IG1 relay, then go to step 14. (See RELAY INSPECTION.)
3	INSPECT STEERING WARMER CONTROL UNIT POWER SUPPLY FUSE • Inspect the C/U IG1 15 A fuse. • Is the fuse normal?	Yes	Go to the next step.
3		No	• If the fuse is deterioration: ― Replace the malfunctioning fuse. • If the fuse is blown: Repair the short to ground in wiring harness between the following terminals: ― C/U IG1 15 A fuse and steering warmer relay terminal A • Go to step 14.
4	INSPECT STEERING WARMER CONTROL UNIT POWER SUPPLY FUSE • Inspect the ST.HEATER 15 A fuse. • Is the fuse normal?	Yes	Go to the next step.
4		No	• If the fuse is deterioration: ― Replace the malfunctioning fuse. • If the fuse is blown: Repair the short to ground in wiring harness between the following terminals: ― ST.HEATER 15 A fuse and steering warmer relay terminal D • Go to step 14.
5	INSPECT STEERING WARMER RELAY • Inspect the steering warmer relay. • Is the relay normal?	Yes	Go to the next step.
5		No	Inspect the steering warmer relay, then go to step 14. (See RELAY INSPECTION.)
6*	VERIFY IF MALFUNCTION CAUSE IS STEERING WARMER CONTROL UNIT POWER SUPPLY 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 manual before handling the air bag system components. (See AIR BAG SYSTEM SERVICE WARNINGS.) (See AIR BAG SYSTEM SERVICE CAUTIONS.) • Switch the ignition off (LOCK). • Disconnect the negative battery terminal and wait for 1 min or more. (See NEGATIVE BATTERY CABLE DISCONNECTION/CONNECTION [SKYACTIV-D 2.2].) (See NEGATIVE BATTERY CABLE DISCONNECTION/CONNECTION [SKYACTIV-G 1.5, SKYACTIV-G 2.0, SKYACTIV-G 2.5].) (See NEGATIVE BATTERY CABLE DISCONNECTION/CONNECTION [MZR 1.6].) (See NEGATIVE BATTERY CABLE DISCONNECTION/CONNECTION [SKYACTIV-D 1.5].) • Remove the driver-side air bag module connector. (See DRIVER-SIDE AIR BAG MODULE REMOVAL.) (See DRIVER-SIDE AIR BAG MODULE INSTALLATION.) • Remove the steering wheel. (See STEERING WHEEL AND COLUMN REMOVAL/INSTALLATION.) • Remove the column cover. (See COLUMN COVER REMOVAL/INSTALLATION.) • Remove the clock spring. (See CLOCK SPRING REMOVAL/INSTALLATION.) • Connect the negative battery terminal. (See NEGATIVE BATTERY CABLE DISCONNECTION/CONNECTION [SKYACTIV-D 2.2].) (See NEGATIVE BATTERY CABLE DISCONNECTION/CONNECTION [SKYACTIV-G 1.5, SKYACTIV-G 2.0, SKYACTIV-G 2.5].) (See NEGATIVE BATTERY CABLE DISCONNECTION/CONNECTION [MZR 1.6].) (See NEGATIVE BATTERY CABLE DISCONNECTION/CONNECTION [SKYACTIV-D 1.5].) • Switch the ignition ON (engine off or on). • Measure the voltage at the following terminals (vehicle wiring harness side). ― Clock spring connector 3 terminal 4A • Is the voltage B+?	Yes	Go to the next step.
6*		No	• Refer to the wiring diagram and verify if there is a common wiring harness between the following terminal. ― Steering warmer relay terminal C and clock spring connector 3 terminal 4A If there is a common connector: • Inspect the common connector and terminals for corrosion, damage, or disconnection and the common wiring harnesses for short to ground to determine the malfunctioning location. • Repair or replace the malfunctioning location. If there is no common connector: • Repair or replace the wiring harness which is shorted to ground. • Replace the fuse. Go to Step 14.
7*	VERIFY IF MALFUNCTION CAUSE IS OPEN CIRCUIT IN WIRING HARNESS BETWEEN CLOCK SPRING CONNECTOR AND BODY GROUND • Switch the ignition OFF (LOCK). • Verify that the clock spring connector 3 is disconnected. • Inspect for continuity between the following terminals (vehicle wiring harness side) and body ground. ― Clock spring connector 3 terminal 4D • Is there continuity?	Yes	Go to the next step.
7*		No	• Refer to the wiring diagram and verify if there is a common connector between the following terminals and body ground. ― Clock spring connector 3 terminal 4D If there is a common connector: • Inspect the common connector and terminals for corrosion, damage, or disconnection and the common wiring harnesses for an open circuit to determine the malfunctioning location. • Repair or replace the malfunctioning location. If there is no common connector: • Repair or replace the wiring harness which has an open circuit. • Go to Step 14.
8*	VERIFY IF MALFUNCTION CAUSE IS SHORT CIRCUIT TO GROUND IN WIRING HARNESS BETWEEN CLOCK SPRING CONNECTOR AND INDICATOR UNIT • Verify that the clock spring connector 3 is disconnected. • Disconnect the indicator unit connector. • Inspect for continuity between clock spring connector 3 terminal 4B (vehicle wiring harness side) and body ground. • Is there continuity?	Yes	• Refer to the wiring diagram and verify if there is a common connector between clock spring connector 3 terminal 4B and indicator unit terminal I. If there is a common connector: ― Inspect the common connector and terminals for corrosion, damage, or disconnection and the common wiring harnesses for short to ground to determine the malfunctioning location. ― Repair or replace the malfunctioning location. If there is no common connector: ― Repair or replace the wiring harness which is shorted to ground. • Go to Step 14.
8*		No	Go to the next step.
9*	VERIFY IF MALFUNCTION CAUSE IS OPEN CIRCUIT IN WIRING HARNESS BETWEEN CLOCK SPRING CONNECTOR AND INDICATOR UNIT • Verify that the clock spring connector 3 and the indicator unit connector are disconnected. • Inspect the wiring harness for continuity between clock spring connector 3 terminal 4B and indicator unit terminal I (vehicle wiring harness side). • Is there continuity?	Yes	Go to the next step.
9*		No	• Refer to the wiring diagram and verify if there is a common connector between clock spring connector 3 terminal 4B and indicator unit terminal I. If there is a common connector: ― Inspect the common connector and terminals for corrosion, damage, or disconnection and the common wiring harnesses for an open circuit to determine the malfunctioning location. ― Repair or replace the malfunctioning location. If there is no common connector: ― Repair or replace the wiring harness which has an open circuit. • Go to Step 14.
10*	DETERMINE IF CAUSE OF MALFUNCTION IS CLOCK SPRING • Inspect for continuity between the following terminals: ― Clock spring connector 3 terminal 4A and 5A ― Clock spring connector 3 terminal 4B and 5B ― Clock spring connector 3 terminal 4D and 5D • Is there continuity?	Yes	Go to the next step.
10*		No	• Inspect the clock spring, then go to step 14. (See CLOCK SPRING INSPECTION.)
11*	VERIFY IF MALFUNCTION CAUSE IS OPEN CIRCUIT IN WIRING HARNESS BETWEEN CLOCK SPRING AND STEERING WARMER CONTROL UNIT • Verify that the steering warmer control unit connector (clock spring side) is disconnected. • Disconnect the is steering warmer control unit connector (unit side). • Inspect for continuity between the following terminals. ― Steering warmer control unit harness connector terminal 5A and D ― Steering warmer control unit harness connector terminal 5B and C ― Steering warmer control unit harness connector terminal 5D and A • Is there continuity?	Yes	Go to the next step.
11*		No	Repair or replace the wiring harness which has an open circuit, then go to step 14.
12*	VERIFY IF MALFUNCTION CAUSE IS OPEN CIRCUIT IN WIRING HARNESS OF STEERING WARMER UNIT CIRCUIT • Inspect for continuity between the following terminals (wiring harness-side); ― Steering warmer unit terminal A and B ― Steering warmer unit terminal C and D • Is there continuity?	Yes	Go to the next step.
12*		No	Repair or replace the wiring harness which has an open circuit, then go to the next step. (See STEERING WHEEL AND COLUMN REMOVAL/INSTALLATION.)
13	DETERMINE IF MALFUNCTION CAUSE IS STEERING WARMER CONTROL UNIT • Reconnect all the disconnected connectors. • Connect the negative battery terminal. (See NEGATIVE BATTERY CABLE DISCONNECTION/CONNECTION [SKYACTIV-D 2.2].) (See NEGATIVE BATTERY CABLE DISCONNECTION/CONNECTION [SKYACTIV-G 1.5, SKYACTIV-G 2.0, SKYACTIV-G 2.5].) (See NEGATIVE BATTERY CABLE DISCONNECTION/CONNECTION [MZR 1.6].) (See NEGATIVE BATTERY CABLE DISCONNECTION/CONNECTION [SKYACTIV-D 1.5].) • Switch the ignition ON (engine off or on). • Operate the steering warmer switch to turn on the steering warmer system. • Does the seat warmer system operate normally?	Yes	Go to the next step.
13		No	Replace the steering warmer control unit, then go to the next step. (See STEERING WARMER CONTROL UNIT REMOVAL/INSTALLATION.)
14	VERIFY IF MALFUNCTION CAUSE IS CORRECTED • Operate the steering warmer switch to turn on the steering warmer system. • Does the seat warmer system operate normally?	Yes	Troubleshooting completed. (Explain the contents of the servicing to the customer.)
14		No	Verify the malfunction symptom in the symptom troubleshooting chart and perform the other applicable malfunction diagnosis. (See SYMPTOM TROUBLESHOOTING [STEERING WARMER].)