Infiniti M45 (Y34). Manual - part 454

DTC P1148, P1168 CLOSED LOOP CONTROL

EC-505

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DTC P1148, P1168 CLOSED LOOP CONTROL

PFP:22690

On Board Diagnosis Logic

ABS002P7

These self-diagnoses have the one trip detection logic.

DTC Confirmation Procedure

ABS002P8

CAUTION:

Always drive vehicle at a safe speed.

NOTE:
If DTC Confirmation Procedure has been previously conducted, always turn ignition switch OFF and wait at
least 10 seconds before conducting the next test.
TESTING CONDITION:

●

Never raise engine speed above 3,000 rpm during the DTC Confirmation Procedure. If the engine
speed limit is exceeded, retry the procedure from step 2.

●

Before performing the following procedure, confirm that battery voltage is more than 11V at idle.

 WITH CONSULT-II

1.

Start engine and warm it up to normal operating temperature.

2.

Turn ignition switch OFF and wait at least 10 seconds,

3.

Select “DATA MONITOR” mode with CONSULT-II.

4.

Hold engine speed at 2,000 rpm and check one of the following.

–

“HO2S1 (B1)/(B2)” voltage should go above 0.70V at least once.

–

“HO2S1 (B1)/(B2)” voltage should go below 0.21V at least once.
If the check result is NG, perform 

EC-506, "Diagnostic Proce-

dure"

 .

If the check result is OK, perform the following step.

5.

Let engine idle at least 5 minutes.

6.

Maintain the following condition at least 50 consecutive sec-
onds.

During this test, P0132 and/or P0152 may be displayed on CONSULT-II screen.

7.

If DTC is detected, go to 

EC-506, "Diagnostic Procedure"

 .

DTC No.

Trouble diagnosis name

DTC detecting condition

Possible cause

P1148
1148
(Bank 1)

Closed loop control 
function

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

●

The heated oxygen sensor 1 circuit is 
open or shorted.

●

Heated oxygen sensor 1

●

Heated oxygen sensor 1 heater

P1168
1168
(Bank 2)

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

B/FUEL SCHDL

4.0 msec or more

ENG SPEED

More than 1,300 rpm

Selector lever

Suitable position

VHCL SPEED SE

More than 71 km/h (44 MPH)

PBIB2025E

EC-506

DTC P1148, P1168 CLOSED LOOP CONTROL

Overall Function Check

ABS002P9

Use this procedure to check the overall function of the closed loop control. During this check, a DTC might not
be confirmed.

 WITH GST

1.

Start engine and warm it up to normal operating temperature.

2.

Turn ignition switch OFF and wait at least 10 seconds,

3.

Start engine and keep the engine speed between 3,500 and 4,000 rpm for at least 1 minute under no load.

4.

Let engine idle for 1 minute.

5.

Set voltmeter probes between ECM terminal 114 [HO2S1 (B1)
signal] or 115 [HO2S1 (B2) signal] and ground.

6.

Check the following with engine speed held at 2,000 rpm con-
stant under no-load.

–

The voltage should go above 0.70V at least once.

–

The voltage should go below 0.21V at least once.

7.

If NG, go to 

EC-506, "Diagnostic Procedure"

 .

Diagnostic Procedure

ABS002PA

Perform trouble diagnosis for “DTC P0133, P0153”. Refer to 

EC-224

 .

PBIB0063E

DTC P1211 TCS CONTROL UNIT

EC-507

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DTC P1211 TCS CONTROL UNIT

PFP:47850

Description

ABS002PB

The malfunction information related to TCS is transferred through the CAN communication line from VDC/
TCS/ABS control unit to ECM.
Be sure to erase the malfunction information such as DTC not only for VDC/TCS/ABS control unit but
also for ECM after TCS related repair.

On Board Diagnosis Logic

ABS002PC

Freeze frame data is not stored in the ECM for this self-diagnosis. The MIL will not light up for this self-
diagnosis.

DTC Confirmation Procedure

ABS002PD

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

 WITH CONSULT-II

1.

Turn ignition switch ON.

2.

Select “DATA MONITOR” mode with CONSULT-II.

3.

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

4.

If 1st trip DTC is detected, go to 

EC-507, "Diagnostic Procedure"

.

 WITH GST

Follow the procedure WITH CONSULT-II above.

Diagnostic Procedure

ABS002PE

Go to 

BRC-11, "TROUBLE DIAGNOSIS"

 .

DTC No.

Trouble diagnosis name

DTC detecting condition

Possible cause

P1211
1211

TCS control unit

ECM receives a malfunction information from 
VDC/TCS/ABS control unit.

●

VDC/TCS/ABS control unit

●

TCS related parts

SEF058Y

EC-508

DTC P1212 TCS COMMUNICATION LINE

DTC P1212 TCS COMMUNICATION LINE

PFP:47850

Description

ABS002PF

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

EC-143, "DTC U1000, U1001 CAN COMMUNICATION LINE"

 .

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

On Board Diagnosis Logic

ABS002PG

Freeze frame data is not stored in the ECM for this self-diagnosis. The MIL will not light up for this self-
diagnosis.

DTC Confirmation Procedure

ABS002PH

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

 WITH CONSULT-II

1.

Turn ignition switch ON.

2.

Select “DATA MONITOR” mode with CONSULT-II.

3.

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

4.

If a 1st trip DTC is detected, go to 

EC-508, "Diagnostic Proce-

dure"

 .

 WITH GST

Follow the procedure WITH CONSULT-II above.

Diagnostic Procedure

ABS002PI

Go to 

BRC-11, "TROUBLE DIAGNOSIS"

 .

DTC No.

Trouble diagnosis name

DTC detecting condition

Possible cause

P1212
1212

TCS communication line

ECM can not receive the information from 
VDC/TCS/ABS control unit continuously.

●

Harness or connectors
(The CAN communication line is open or 
shorted.)

●

VDC/TCS/ABS control unit

●

Dead (Weak) battery

SEF058Y