Infiniti G37 Coupe. Manual - part 550

P1148, P1168 CLOSED LOOP CONTROL

EC-381

< COMPONENT DIAGNOSIS >

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P1148, P1168 CLOSED LOOP CONTROL

DTC Logic

INFOID:0000000001734183

DTC DETECTION LOGIC

NOTE:
DTC P1148 or P1168 is displayed with another DTC for A/F sensor 1.
Perform the trouble diagnosis for the corresponding DTC.

DTC No.

Trouble diagnosis name

DTC detecting condition

Possible cause

P1148

Closed loop control 
function (bank 1)

The closed loop control function for bank 1 does 
not operate even when vehicle is driving in the 
specified condition.

• Harness or connectors

(The A/F sensor 1 circuit is open or short-
ed.)

• A/F sensor 1
• A/F sensor 1 heater

P1168

Closed loop control 
function (bank 2)

The closed loop control function for bank 2 does 
not operate even when vehicle is driving in the 
specified condition.

EC-382

< COMPONENT DIAGNOSIS >

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P1211 TCS CONTROL UNIT

P1211 TCS CONTROL UNIT

Description

INFOID:0000000001734184

The malfunction information related to TCS is transferred through the CAN communication line from “ABS
actuator and electric unit (control unit)” to ECM.
Be sure to erase the malfunction information such as DTC not only for “ABS actuator and electric unit
(control unit)” but also for ECM after TCS related repair.

DTC Logic

INFOID:0000000001734185

DTC DETECTION LOGIC

Freeze frame data is not stored in the ECM for this self-diagnosis.

DTC CONFIRMATION PROCEDURE

1.

PRECONDITIONING

TESTING CONDITION:
Before performing the following procedure, confirm that battery voltage is more than 10.5V at idle.

>> GO TO 2.

2.

PERFORM DTC CONFIRMATION PROCEDURE

1.

Start engine and let it idle for at least 60 seconds.

2.

Check 1st trip DTC.

Is 1st trip DTC detected?

YES

>>

EC-382, "Diagnosis Procedure"

NO

>> INSPECTION END

Diagnosis Procedure

INFOID:0000000001734186

Go to 

BRC-4, "Work Flow"

.

DTC No.

Trouble diagnosis name

DTC detecting condition

Possible cause

P1211

TCS control unit

ECM receives a malfunction information from
“ABS actuator and electric unit (control unit)”.

• ABS actuator and electric unit (control 

unit)

• TCS related parts

P1212 TCS COMMUNICATION LINE

EC-383

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P1212 TCS COMMUNICATION LINE

Description

INFOID:0000000001734187

This CAN communication line is used to control the smooth engine operation during the TCS operation. Pulse
signals are exchanged between ECM and “ABS actuator and electric unit (control unit)”.
Be sure to erase the malfunction information such as DTC not only for “ABS actuator and electric unit
(control unit)” but also for ECM after TCS related repair.

DTC Logic

INFOID:0000000001734188

DTC DETECTION LOGIC

NOTE:
• If DTC P1212 is displayed with DTC U1000 or U1001, first perform the trouble diagnosis for DTC

U1000, U1001. Refer to 

EC-146, "DTC Logic"

.

• If DTC P1212 is displayed with DTC U1010, first perform the trouble diagnosis for DTC U1010. Refer

to 

EC-147, "DTC Logic"

.

Freeze frame data is not stored in the ECM for this self-diagnosis.

DTC CONFIRMATION PROCEDURE

1.

PRECONDITIONING

TESTING CONDITION:
Before performing the following procedure, confirm that battery voltage is more than 10.5V at idle.

>> GO TO 2.

2.

PERFORM DTC CONFIRMATION PROCEDURE

1.

Start engine and let it idle for at least 10 seconds.

2.

Check 1st trip DTC.

Is 1st trip DTC detected?

YES

>> Go to 

EC-383, "Diagnosis Procedure"

.

NO

>> INSPECTION END

Diagnosis Procedure

INFOID:0000000001734189

Go to 

BRC-4, "Work Flow"

.

DTC No.

Trouble diagnosis name

DTC detecting condition

Possible cause

P1212

TCS communication line

ECM can not receive the information from 
“ABS actuator and electric unit (control 
unit)” continuously.

• Harness or connectors

(The CAN communication line is open or short-
ed.)

• ABS actuator and electric unit (control unit)
• Dead (Weak) battery

EC-384

< COMPONENT DIAGNOSIS >

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P1217 ENGINE OVER TEMPERATURE

P1217 ENGINE OVER TEMPERATURE

DTC Logic

INFOID:0000000001734190

DTC DETECTION LOGIC

NOTE:
• If DTC P1217 is displayed with DTC U1000 or U1001, first perform the trouble diagnosis for DTC

U1000, U1001. Refer to 

EC-146, "DTC Logic"

.

• If DTC P1217 is displayed with DTC U1010, first perform the trouble diagnosis for DTC U1010. Refer

to 

EC-147, "DTC Logic"

.

If the cooling fan or another component in the cooling system malfunctions, engine coolant temperature will
rise.
When the engine coolant temperature reaches an abnormally high temperature condition, a malfunction is
indicated.

CAUTION:

When a malfunction is indicated, be sure to replace the coolant. Refer to 

CO-8, "Draining"

 and 

CO-9,

"Refilling"

. Also, replace the engine oil. Refer to 

LU-7, "Draining"

and 

LU-8, "Refilling"

.

1.

Fill radiator with coolant up to specified level with a filling speed of 2 liters per minute. Be sure to
use coolant with the proper mixture ratio. Refer to 

MA-11, "Anti-Freeze Coolant Mixture Ratio"

.

2.

After refilling coolant, run engine to ensure that no water-flow noise is emitted.

DTC CONFIRMATION PROCEDURE

1.

PERFORM COMPONENT FUNCTION CHECK

Perform component function check. Refer to 

EC-384, "Component Function Check"

.

NOTE:
Use component function check to check the overall function of the cooling fan. During this check, a DTC might
not be confirmed.
Is the inspection result normal?

YES

>> INSPECTION END

NO

>> Go to 

EC-385, "Diagnosis Procedure"

.

Component Function Check

INFOID:0000000001734191

1.

PERFORM COMPONENT FUNCTION CHECK-I

WARNING:

Never remove the radiator cap when the engine is hot. Serious burns could be caused by high pres-
sure fluid escaping from the radiator.
Wrap a thick cloth around cap. Carefully remove the cap by turning it a quarter turn to allow built-up
pressure to escape. Then turn the cap all the way off.

DTC No.

Trouble diagnosis name

DTC detecting condition

Possible cause

P1217

Engine over tempera-
ture (Overheat)

• Cooling fan does not operate properly (Over-

heat).

• Cooling fan system does not operate proper-

ly (Overheat).

• Engine coolant was not added to the system 

using the proper filling method.

• Engine coolant is not within the specified 

range.

• Harness or connectors

(The cooling fan circuit is open or short-
ed.)

• IPDM E/R
• Cooling fan control module
• Cooling fan motor
• Radiator  hose
• Radiator
• Radiator  cap
• Water pump
• Thermostat