Suzuki Grand Vitara JB416 / JB420 / JB419. Manual - part 374

7A-6 Heater and Ventilation: 

Additional Heater System Component Location (Diesel Engine Model)

S6JB0A7103002

Diagnostic Information and Procedures

Heater and Ventilation System Check

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1

3

4

5

2

I5JB0B710004-01

1. Additional heater assembly

3. Additional heater relay No.1

5. Additional heater relay No.3

2. ECM

4. Additional heater relay No.2

Step

Action

Yes

No

1

)

 Customer complaint analysis

1) Perform “Customer complaint analysis”.

Was customer complaint analysis performed?

Go to Step 2.

Perform customer 
complaint analysis.

2

)

 DTC check

1) Perform “DTC check”.

Is there any DTC code?

Go to Step 3.

Go to Step 4.

3

)

 Troubleshooting malfunction

1) Perform “Troubleshooting malfunction”.

Is there any faulty condition?

Repair or replace 
malfunction part, and go 
to Step 7.

Go to Step 5.

4

)

 Visual inspection

1) Perform “Visual inspection”.

Is there any faulty condition?

Repair or replace 
malfunction part.

Go to Step 5.

5

)

 Perform heater and ventilation system symptom 

diagnosis
1) Inspect and repair referring to “Heater and Ventilation 

Symptom Diagnosis”.

Is there any faulty condition?

Repair or replace 
malfunction part, and go 
to Step 7.

Go to Step 6.

Heater and Ventilation:  7A-7

Description for Each Step
Step 1. Customer complaint analysis
Talk to customer, and then record details of the problem.

Customer questionnaire (example)

NOTE
The form is a standard sample. It should be modified according to conditions characteristic of each 
market.

 

6

)

 Check for intermittent problem

1) Check for intermittent troubles referring to “Intermittent 

and Poor Connection Inspection in Section 00”.

Is there any faulty condition?

Repair or replace 
malfunction part, and go 
to Step 7.

Go to Step 7.

7

)

 Final confirmation test

1) Perform “Final confirmation test”.

Is there any malfunction code?

Go to Step 4.

Heater and ventilation 
system is in good 
condition.

Step

Action

Yes

No

Customer’s Name:

Model:

VIN:

Date of Issue:

Date of Reg.

Date of Problem:

Mileage:

Problem Symptoms

• REC indicator lamp and/or FRE indicator lamp abnormal: fails to turn on / fails to turn 

off / flashes

• Abnormal noise while is working: from blower motor / from HVAC unit / from engine 

room, other_______________

• Air intake selector dose not work:
• Blower speed selector dose not work:
• Temperature selector dose not work:
• Other:

Frequency of Occurrence

• Continuous / Intermittent (_____ times a day, a month) / other_______________

Conditions for Occurrence of 
Problem

• Vehicle at stop & blower motor is working:
• For some time after blower speed selector is ON:
• When outside air temperature is high:
• When outside air temperature is low:
• All the time:

Environmental Condition

• Weather: fair / cloudy / rain / snow / other_______________
• Temperature: _____ 

°F (_____ °C)

Diagnostic Trouble Code

• First check: Normal code / malfunction code (__________)
• Second check: Normal code / malfunction code (__________)

7A-8 Heater and Ventilation: 

Step 2. Visual inspection
As a preliminary step, be sure to perform visual check of the items that support proper function of the heater and 
ventilation referring to “Visual Inspection”.

Step 3. DTC check
Check DTC referring to “DTC Check”.

Step 4. Troubleshooting malfunction
Based on the DTC, perform an applicable DTC diagnostic flow and locate the cause of the trouble, namely in a sensor, 
wire harness, connector, actuator, HVAC control module or other part and repair faulty parts.

Step 5. Heater and ventilation system symptom diagnosis
Check any part or system suspected to be a possible cause referring to “Heater and Ventilation Symptom Diagnosis”.

Step 6. Check for intermittent problem
Check any part where an intermittent trouble is easy to occur (e.g., wire harness, connector, etc.), referring to 
“Intermittent and Poor Connection Inspection in Section 00” and related circuit of trouble cord recorded.

Step 7. Final confirmation test
Confirm if the problem symptom is troubleshooting and the heater and ventilation system is free from any abnormal 
conditions. If there existed DTC, clear the DTC. Then, check if the DTC is still detected and if there is any other DTC.

Visual Inspection

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Check visually the following parts and systems.

DTC Check

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DTC check is the same as vehicle equipped with A/C system.
Refer to “DTC Check in Section 7B”.

DTC Clearance

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DTC clearance is the same as vehicle equipped with A/C system.
Refer to “DTC Clearance in Section 7B”.

DTC Table

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DTC table is the same as vehicle equipped with A/C system.
Refer to “DTC Table in Section 7B”.

Fail-Safe Table

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Fail-safe table is the same as vehicle equipped with A/C system.
Refer to “Fail-Safe Table in Section 7B”.

Scan Tool Data

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Scan tool data is the same as vehicle equipped with A/C system.
Refer to “Scan Tool Data in Section 7B”.

Inspection item

Correction

• Engine coolant
• Heater pipe and/or hose
• Battery
• Connectors of electric wire harness
• Fuses
• Parts
• Other parts that can be checked visually

• Leakage
• Disconnection, looseness and deterioration
• Fluid level and corrosion of terminal
• Disconnection and friction
• Burning
• Installation and damage

Heater and Ventilation:  7A-9

Heater and Ventilation Symptom Diagnosis

S6JB0A7104008

Condition

Possible cause

Correction / Reference Item

Blower won’t work even 
when blower speed 
selector is ON

Blower fuse blown

Replace fuse to check for short.

Blower motor faulty

Check blower motor referring to “Blower Motor 
Inspection”.

Blower motor relay faulty

Check relay referring to “Blower Motor Relay 
Inspection”.

Blower motor controller faulty

Check blower motor controller referring to 
“Blower Motor Controller Inspection”.

Blower speed selector faulty

Check HVAC control module referring to 
“HVAC Control Module and Its Circuits 
Inspection (for Vehicle without A/C)” or “HVAC 
Control Module and Its Circuits Inspection in 
Section 7B”.

Wiring or grounding faulty

Repair as necessary.

Air temperature is not 
changed even when 
temperature selector is 
changed

Temperature control door broken

Repair Temperature control door.

Linkage broken

Check actuator linkage referring to “Actuator 
Linkage Inspection”.

Heater hoses leaking or clogged

Replace hoses.

Heater core leaking or clogged

Replace heater core referring to “Heater Core 
Removal and Installation”.

Temperature control actuator faulty

Check temperature control actuator referring to 
“Temperature Control Actuator Inspection”.

Temperature selector faulty

Check HVAC control module referring to 
“HVAC Control Module and Its Circuits 
Inspection (for Vehicle without A/C)” or “HVAC 
Control Module and Its Circuits Inspection in 
Section 7B”.

Air outlet port is not 
changed when air flow 
selector is changed

Air flow control door broken 

Repair air flow control door.

Linkage broken

Check actuator linkage referring to “Actuator 
Linkage Inspection”.

Air flow control actuator faulty

Check air flow control actuator referring to “Air 
Flow Control Actuator Inspection”.

Mode selector faulty

Check HVAC control module referring to 
“HVAC Control Module and Its Circuits 
Inspection (for Vehicle without A/C)” or “HVAC 
Control Module and Its Circuits Inspection in 
Section 7B”.

No fresh air inlet is 
changed.

Fuse blown

Check related fuses and check for short circuit 
to ground.

Air intake control actuator faulty

Check air intake control actuator.

Air intake control door broken

Repair air intake control door.

Linkage broken

Check actuator linkage referring to “Actuator 
Linkage Inspection”.

Air intake selector faulty

Check HVAC Control module referring to 
“HVAC Control Module and Its Circuits 
Inspection (for Vehicle without A/C)” or “HVAC 
Control Module and Its Circuits Inspection in 
Section 7B”.

Wiring or grounding faulty

Repair or replace as necessary.