Nissan Titan. Manual — part 374

HAC-1

VENTILATION, HEATER & AIR CONDITIONER

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SECTION

HAC

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HAC

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CONTENTS

HEATER & AIR CONDITIONING CONTROL SYSTEM

AUTOMATIC AIR CONDITIONER

BASIC INSPECTION . . . . . . . . .

5

DIAGNOSIS AND REPAIR WORKFLOW . . ..

5

How to Perform Trouble Diagnosis For Quick And
Accurate Repair . . . . . . . . . . . . . ....

5

INSPECTION AND ADJUSTMENT . . . . . .

6

Operational Check . . . . . . . . . . . . ....

6

SYSTEM DESCRIPTION . . . . . . . ..

8

FUNCTION INFORMATION . . . . . . . .

8

Component Part Location . . . . . . . . . .....

8

Symptom Table . . . . . . . . . . . . . ...

10

REFRIGERATION SYSTEM . . . . . . . ..

11

Refrigerant Cycle . . . . . . . . . . . . .

11

Refrigerant System Protection . . . . . . . .

11

AUTOMATIC AIR CONDITIONER SYSTEM . .

13

Control System Diagram . . . . . . . . . . .

13

Control System Description . . . . . . . . . .

13

Discharge Air Flow . . . . . . . . . . . . ..

15

Switches And Their Control Function . . . . . ..

16

DIAGNOSIS SYSTEM (HVAC) . . . . . . ..

17

CONSULT Function (HVAC) . . . . . . . . ...

17

DIAGNOSIS SYSTEM (BCM) . . . . . . .

19

CONSULT Function (BCM - COMMON ITEM) . ...

19

CONSULT Function (BCM - AIR CONDITIONER) .

19

SELF-DIAGNOSIS FUNCTION . . . . . . ..

21

Front Air Control Self-Diagnosis . . . . . . . ..

21

Front Air Control Self-Diagnosis Code Chart . . ..

21

DTC/CIRCUIT DIAGNOSIS . . . . . . .

22

MODE DOOR MOTOR . . . . . . . . . ...

22

System Description . . . . . . . . . . . . .

22

Mode Door Motor Component Function Check . ...

23

Mode Door Motor Diagnosis Procedure . . . . ..

23

AIR MIX DOOR MOTOR . . . . . . . . ...

27

System Description . . . . . . . . . . . . ..

27

Air Mix Door Motor (Driver) Component Function
Check . . . . . . . . . . . . . . . . . ..

28

Air Mix Door Motor (Driver) Diagnosis Procedure .

28

Air Mix Door Motor (Passenger) Component
Function Check . . . . . . . . . . . . . .

31

Air Mix Door Motor (Passenger) Diagnosis Proce-
dure . . . . . . . . . . . . . . . . . . .

32

INTAKE DOOR MOTOR . . . . . . . . ...

35

System Description . . . . . . . . . . . . ..

35

Intake Door Motor Component Function Check . ..

36

Intake Door Motor Diagnosis Procedure . . . . .

36

DEFROSTER DOOR MOTOR CIRCUIT . . ...

38

System Description . . . . . . . . . . . . ..

38

Defroster Door Motor Component Function Check

.

38

Defroster Door Motor Diagnosis Procedure . . .

39

BLOWER MOTOR CONTROL SYSTEM . . ..

43

System Description . . . . . . . . . . . . ..

43

Front Blower Motor Component Function Check .

44

Front Blower Motor Diagnosis Procedure . . . .

44

Front Blower Motor Component Inspection . . . .

48

MAGNET CLUTCH . . . . . . . . . . ...

49

System Description . . . . . . . . . . . . ..

49

Magnet Clutch Component Function Check . . .

49

Magnet Clutch Diagnosis Procedure . . . . . ...

49

WATER VALVE CIRCUIT . . . . . . . . .

54

Description . . . . . . . . . . . . . . . ...

54

Water Valve Diagnosis Procedure . . . . . . ...

54

AMBIENT SENSOR . . . . . . . . . . ..

56

Component Description . . . . . . . . . . ...

56

Ambient Sensor Diagnosis Procedure . . . . . .

56

Ambient Sensor Component Inspection . . . . ..

57

HAC-2

IN-VEHICLE SENSOR . . . . . . . . . ...

59

Component Description . . . . . . . . . . ..

59

In-Vehicle Sensor Diagnosis Procedure . . . . .

59

In-Vehicle Sensor Component Inspection . . . ..

61

OPTICAL SENSOR . . . . . . . . . . ...

62

Component Description . . . . . . . . . . ..

62

Optical Sensor Diagnosis Procedure . . . . . ..

62

INTAKE SENSOR . . . . . . . . . . . ..

64

System Description . . . . . . . . . . . . .

64

Intake Sensor Diagnosis Procedure . . . . . ...

64

Intake Sensor Component Inspection . . . . ....

65

POWER SUPPLY AND GROUND CIRCUIT
FOR CONTROLLER . . . . . . . . . . ..

67

Component Description . . . . . . . . . . ..

67

Front Air Control Component Function Check . ....

67

Front Air Control Power and Ground Diagnosis
Procedure . . . . . . . . . . . . . . . ...

67

ECU DIAGNOSIS INFORMATION . . . ..

69

AIR CONDITIONER CONTROL . . . . . .

69

Front Air Control Terminals Reference Values . ...

69

WIRING DIAGRAM . . . . . . . . . .

71

AIR CONDITIONER CONTROL . . . . . .

71

Wiring Diagram - Automatic Air Conditioner . . ...

71

SYMPTOM DIAGNOSIS . . . . . . . .

82

AIR CONDITIONER CONTROL . . . . . .

82

Symptom Matrix Chart . . . . . . . . . . ..

82

INSUFFICIENT COOLING . . . . . . . . .

83

Component Function Check . . . . . . . . ...

83

Diagnostic Work Flow . . . . . . . . . . . .

84

Performance Chart . . . . . . . . . . . . .

86

Trouble Diagnoses for Abnormal Pressure . . ....

87

INSUFFICIENT HEATING . . . . . . . . .

91

Component Function Check . . . . . . . . ...

91

NOISE . . . . . . . . . . . . . . . .

93

Component Function Check . . . . . . . . ...

93

MEMORY FUNCTION DOES NOT OPERATE ...

94

Memory Function Check . . . . . . . . . . .

94

PRECAUTION . . . . . . . . . . . .

95

PRECAUTIONS . . . . . . . . . . . . .

95

Precaution for Supplemental Restraint System
(SRS) "AIR BAG" and "SEAT BELT PRE-TEN-
SIONER" . . . . . . . . . . . . . . . . .

95

Working with HFC-134a (R-134a) . . . . . . ..

95

Precaution for Service Equipment . . . . . . ..

96

MANUAL A/C (TYPE 1)

BASIC INSPECTION . . . . . . . . ...

97

MANUAL A/C IDENTIFICATION TABLE . . ..

97

Application Table . . . . . . . . . . . . .

97

DIAGNOSIS AND REPAIR WORKFLOW . . .

98

How to Perform Trouble Diagnosis For Quick And
Accurate Repair . . . . . . . . . . . . . ..

98

INSPECTION AND ADJUSTMENT . . . . ...

99

Operational Check . . . . . . . . . . . . ..

99

SYSTEM DESCRIPTION . . . . . . ..

101

MANUAL A/C IDENTIFICATION TABLE . . .

101

Application Table . . . . . . . . . . . . ..

101

FUNCTION INFORMATION . . . . . . . .

102

Component Part Location . . . . . . . . . .

102

Symptom Table . . . . . . . . . . . . . .

104

REFRIGERATION SYSTEM . . . . . . . .

105

Refrigerant Cycle . . . . . . . . . . . . ..

105

Refrigerant System Protection . . . . . . . ..

105

MANUAL AIR CONDITIONER SYSTEM . . .

107

Control System Diagram . . . . . . . . . ...

107

Control System Description . . . . . . . . ..

107

Discharge Air Flow . . . . . . . . . . . .

109

Switches And Their Control Function . . . . .

109

DIAGNOSIS SYSTEM (HVAC) . . . . . . .

111

CONSULT Function (HVAC) . . . . . . . . .

111

DIAGNOSIS SYSTEM (BCM) . . . . . . ...

112

CONSULT Function (BCM - COMMON ITEM) . .

112

CONSULT Function (BCM - AIR CONDITIONER) .

112

SELF-DIAGNOSIS FUNCTION . . . . . .

114

Front Air Control Self-Diagnosis . . . . . . ...

114

Front Air Control Self-Diagnosis Code Chart . .

114

DTC/CIRCUIT DIAGNOSIS . . . . . ...

115

MANUAL A/C IDENTIFICATION TABLE . . .

115

Application Table . . . . . . . . . . . . ..

115

MODE DOOR MOTOR . . . . . . . . . .

116

System Description . . . . . . . . . . . ...

116

Mode Door Motor Component Function Check .

116

Mode Door Motor Diagnosis Procedure . . . .

116

AIR MIX DOOR MOTOR . . . . . . . . ..

120

System Description . . . . . . . . . . . ...

120

Air Mix Door Motor Component Function Check ..

120

Air Mix Door Motor Diagnosis Procedure . . . ..

121

INTAKE DOOR MOTOR . . . . . . . . ...

125

System Description . . . . . . . . . . . ...

125

Intake Door Motor Component Function Check .

125

Intake Door Motor Diagnosis Procedure . . . ...

126

DEFROSTER DOOR MOTOR CIRCUIT . . ..

127

System Description . . . . . . . . . . . ...

127

HAC-3

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HAC

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Defroster Door Motor Component Function Check

..

127

Defroster Door Motor Diagnosis Procedure . . ..

127

BLOWER MOTOR CONTROL SYSTEM . . .

131

System Description . . . . . . . . . . . ...

131

Front Blower Motor Component Function Check ..

131

Front Blower Motor Diagnosis Procedure . . . .

132

Front Blower Motor Component Inspection . . ...

135

MAGNET CLUTCH . . . . . . . . . . ...

137

System Description . . . . . . . . . . . ...

137

Magnet Clutch Component Function Check . . .

137

Magnet Clutch Diagnosis Procedure . . . . . .

137

WATER VALVE CIRCUIT . . . . . . . .

142

Description . . . . . . . . . . . . . . .

142

Water Valve Diagnosis Procedure . . . . . .

142

AMBIENT SENSOR . . . . . . . . . . .

144

Component Description . . . . . . . . . . .

144

Ambient Sensor Diagnosis Procedure . . . . ..

144

Ambient Sensor Component Inspection . . . .

145

INTAKE SENSOR . . . . . . . . . . .

147

System Description . . . . . . . . . . . ...

147

Intake Sensor Diagnosis Procedure . . . . . ..

147

Intake Sensor Component Inspection . . . . ...

148

POWER SUPPLY AND GROUND CIRCUIT
FOR CONTROLLER . . . . . . . . . .

150

Component Description . . . . . . . . . . .

150

Front Air Control Component Function Check . ..

150

Front Air Control Power and Ground Diagnosis
Procedure . . . . . . . . . . . . . . . ..

150

ECU DIAGNOSIS INFORMATION . . .

152

MANUAL A/C IDENTIFICATION TABLE . .

152

Application Table . . . . . . . . . . . . ...

152

AIR CONDITIONER CONTROL . . . . . ...

153

Front Air Control Terminals Reference Values . .

153

WIRING DIAGRAM . . . . . . . . .

155

AIR CONDITIONER CONTROL . . . . . ...

155

Wiring Diagram - Manual With 2 Control Dial Sys-
tem . . . . . . . . . . . . . . . . . .

155

SYMPTOM DIAGNOSIS . . . . . . .

165

MANUAL A/C IDENTIFICATION TABLE . .

165

Application Table . . . . . . . . . . . . ...

165

AIR CONDITIONER CONTROL . . . . . ...

166

Symptom Matrix Chart . . . . . . . . . . .

166

INSUFFICIENT COOLING . . . . . . . ...

167

Component Function Check . . . . . . . . ..

167

Diagnostic Work Flow . . . . . . . . . . ...

168

Performance Chart . . . . . . . . . . . .

170

Trouble Diagnoses for Abnormal Pressure . . ...

171

INSUFFICIENT HEATING . . . . . . . ...

175

Component Function Check . . . . . . . . ..

175

NOISE . . . . . . . . . . . . . . . ..

177

Component Function Check . . . . . . . . ..

177

PRECAUTION . . . . . . . . . . .

178

PRECAUTIONS . . . . . . . . . . . ...

178

Precaution for Supplemental Restraint System
(SRS) "AIR BAG" and "SEAT BELT PRE-TEN-
SIONER" . . . . . . . . . . . . . . . ...

178

Working with HFC-134a (R-134a) . . . . . . .

178

Precaution for Service Equipment . . . . . . .

179

MANUAL A/C (TYPE 2)

BASIC INSPECTION . . . . . . . . .

180

MANUAL A/C IDENTIFICATION TABLE . ...

180

Application Table . . . . . . . . . . . . ...

180

DIAGNOSIS AND REPAIR WORKFLOW . ..

181

How to Perform Trouble Diagnosis For Quick And
Accurate Repair . . . . . . . . . . . . . .

181

INSPECTION AND ADJUSTMENT . . . .

182

Operational Check . . . . . . . . . . . . .

182

SYSTEM DESCRIPTION . . . . . . ...

184

MANUAL A/C IDENTIFICATION TABLE . ...

184

Application Table . . . . . . . . . . . . ...

184

FUNCTION INFORMATION . . . . . . .

185

Component Part Location . . . . . . . . . ..

185

Symptom Table . . . . . . . . . . . . . .

187

REFRIGERATION SYSTEM . . . . . . ...

188

Refrigerant Cycle . . . . . . . . . . . . ...

188

Refrigerant System Protection . . . . . . . ...

188

MANUAL AIR CONDITIONER SYSTEM . .

190

Control System Diagram . . . . . . . . . ...

190

Control System Description . . . . . . . . ...

190

Discharge Air Flow . . . . . . . . . . . .

191

Switches And Their Control Function . . . . .

192

DIAGNOSIS SYSTEM (BCM) . . . . . . .

194

CONSULT Function (BCM - COMMON ITEM) . ..

194

CONSULT Function (BCM - AIR CONDITIONER) ..

194

DTC/CIRCUIT DIAGNOSIS . . . . . ...

196

MANUAL A/C IDENTIFICATION TABLE . ...

196

Application Table . . . . . . . . . . . . ...

196

MODE DOOR MOTOR . . . . . . . . .

197

System Description . . . . . . . . . . . .

197

Mode Door Motor Component Function Check . .

197

Mode Door Motor Diagnosis Procedure . . . .

197

HAC-4

AIR MIX DOOR MOTOR . . . . . . . . ..

201

System Description . . . . . . . . . . . .

201

Air Mix Door Motor Component Function Check ...

201

Air Mix Door Motor Diagnosis Procedure . . . ..

202

INTAKE DOOR MOTOR . . . . . . . . ..

205

System Description . . . . . . . . . . . .

205

Intake Door Motor Component Function Check .

205

Intake Door Motor Diagnosis Procedure . . . ...

206

DEFROSTER DOOR MOTOR CIRCUIT . . .

207

System Description . . . . . . . . . . . .

207

Defroster Door Motor Component Function Check

..

207

Defroster Door Motor Diagnosis Procedure . . ...

207

BLOWER MOTOR CONTROL SYSTEM . .

211

System Description . . . . . . . . . . . .

211

Front Blower Motor Component Function Check ...

211

Front Blower Motor Diagnosis Procedure . . . ..

212

Front Blower Motor Component Inspection . . ...

215

MAGNET CLUTCH . . . . . . . . . . ..

217

System Description . . . . . . . . . . . .

217

Magnet Clutch Component Function Check . . ..

217

Magnet Clutch Diagnosis Procedure . . . . . .

217

WATER VALVE CIRCUIT . . . . . . . .

222

Description . . . . . . . . . . . . . . . .

222

Water Valve Diagnosis Procedure . . . . . . .

222

INTAKE SENSOR . . . . . . . . . . .

224

System Description . . . . . . . . . . . .

224

Intake Sensor Diagnosis Procedure . . . . . ..

224

Intake Sensor Component Inspection . . . . ...

225

POWER SUPPLY AND GROUND CIRCUIT
FOR CONTROLLER . . . . . . . . . .

227

Component Description . . . . . . . . . . .

227

Front Air Control Component Function Check . ...

227

Front Air Control Power and Ground Diagnosis
Procedure . . . . . . . . . . . . . . . ..

227

ECU DIAGNOSIS INFORMATION . . .

229

MANUAL A/C IDENTIFICATION TABLE . . .

229

Application Table . . . . . . . . . . . . ..

229

AIR CONDITIONER CONTROL . . . . . ...

230

Front Air Control Terminals Reference Values . .

230

WIRING DIAGRAM . . . . . . . . ...

232

AIR CONDITIONER CONTROL . . . . . ...

232

Wiring Diagram - Manual With 3 Control Dial Sys-
tem . . . . . . . . . . . . . . . . . .

232

SYMPTOM DIAGNOSIS . . . . . . ...

242

MANUAL A/C IDENTIFICATION TABLE . . .

242

Application Table . . . . . . . . . . . . ..

242

AIR CONDITIONER CONTROL . . . . . ...

243

Symptom Matrix Chart . . . . . . . . . . .

243

INSUFFICIENT COOLING . . . . . . . .

244

Component Function Check . . . . . . . . .

244

Diagnostic Work Flow . . . . . . . . . . ...

245

Performance Chart . . . . . . . . . . . .

247

Trouble Diagnoses for Abnormal Pressure . . ...

248

INSUFFICIENT HEATING . . . . . . . .

252

Component Function Check . . . . . . . . .

252

NOISE . . . . . . . . . . . . . . . ...

254

Component Function Check . . . . . . . . .

254

PRECAUTION . . . . . . . . . . ...

255

PRECAUTIONS . . . . . . . . . . . .

255

Precaution for Supplemental Restraint System
(SRS) "AIR BAG" and "SEAT BELT PRE-TEN-
SIONER" . . . . . . . . . . . . . . . ...

255

Working with HFC-134a (R-134a) . . . . . . .

255

Precaution for Service Equipment . . . . . .

256