2004 INFINITI QX56 relay

TROUBLE DIAGNOSIS
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P POSI IND (ON-OFF display) — — X
R POSI IND (ON-OFF display) — — X
N POSI IND (ON-OFF display) — — X
D POSI IND (ON-OFF display) — — X
4TH POSI IND (ON-OFF display) — — X
3RD POSI IND (ON-OFF display) — — X
2ND POSI IND (ON-OFF display) — — X
1ST POSI IND (ON-OFF display) — — X
MANU MODE IND (ON-OFF display) — — X
Not mounted but displayed.
POWER M LAMP (ON-OFF display) — — X
F-SAFE IND/L (ON-OFF display) — — X
ATF WARN LAMP (ON-OFF display) — — X
BACK-UP LAMP (ON-OFF display) — — X
STARTER RELAY (ON-OFF display) — — X
PNP SW3 MON (ON-OFF display) — — X
C/V CLB ID1 — — X
C/V CLB ID2 — — X
C/V CLB ID3 — — X
UNIT CLB ID1 — — X
UNIT CLB ID2 — — X
UNIT CLB ID3 — — X
TRGT GR RATIO — — X
TRGT PRES TCC (kPa) — — X
TRGT PRES L/P (kPa) — — X
TRGT PRES I/C (kPa) — — X
TRGT PRE FR/B (kPa) — — X
TRGT PRES D/C (kPa) — — X
TRG PRE HLR/C (kPa) — — X
SHIFT PATTERN — — X
DRV CST JUDGE — — X
START RLY MON — — X
NEXT GR POSI — — X
SHIFT MODE — — X
MANU GR POSI — — X
VEHICLE SPEED (km/h) — X X Vehicle speed recognized by the TCM.
Voltage (V) — — XDisplays the value measured by the voltage
probe.
Frequency (Hz) — — X
The value measured by the pulse probe is dis-
played. DUTY-HI (high) (%) — — X
DUTY-LOW (low) (%) — — X
PLS WIDTH-HI (ms) — — X
PLS WIDTH-LOW (ms) — — XMonitored item (Unit)Monitor Item Selection
Remarks ECU
INPUT
SIGNALSMAIN SIG-
NALSSELEC-
TION
FROM
MENU

DTC P0615 START SIGNAL CIRCUIT
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DTC P0615 START SIGNAL CIRCUITPFP:25230
DescriptionUCS002DE

TCM controls park/neutral (PNP) relay (starter relay) in IPDM E/R.

TCM switches PNP relay “ON” at “P” or “N” position and allows to crank engine.

Then it prohibits cranking other than at “P” or “N” position.
CONSULT-II Reference ValueUCS002DF
On Board Diagnosis LogicUCS002DG

This is not an OBD-II self-diagnostic item.

Diagnostic trouble code “STARTER RELAY/CIRC” with CONSULT-II is detected when detects as irregular
when park/neutral (PNP) relay (starter relay) is switched “ON” other than at “P” or “N” position. (Or when
switched “OFF” at “P” or “N” position).
Possible CauseUCS002D H

Harness or connectors
[The park/neutral position (PNP) relay (starter relay) and TCM circuit is open or shorted.]

Park/neutral position (PNP) relay (starter relay)
DTC Confirmation ProcedureUCS002DI
NOTE:
If “DTC Confirmation Procedure” has been previously performed, always turn ignition switch “OFF”
and wait at least 10 seconds before performing the next test.
After the repair, perform the following procedure to confirm the malfunction is eliminated.
WITH CONSULT-II
1. Turn ignition switch “ON”. (Do not start engine.)
2. Select “DATA MONITOR” mode for “A/T” with CONSULT-II.
3. Start engine.
4. Drive vehicle for at least 2 consecutive seconds.
5. If DTC is detected, go to AT - 1 0 6 , "
Diagnostic Procedure" .
Item name Condition Display value
STARTER RELAYSelector lever in “N”,“P” position. ON
Selector lever in other position. OFF
BCIA0030E

AT-106
DTC P0615 START SIGNAL CIRCUIT
Revision: August 20072004 QX56
Diagnostic ProcedureUCS002DJ
1. CHECK STARTER RELAY
With CONSULT-II
1. Turn ignition switch “ON”. (Do not start engine.)
2. Select “SELECTION FROM MENU” in “DATA MONITOR” mode
for “A/T” with CONSULT-II and check monitor “STARTER
RELAY” ON/OFF.
Without CONSULT-II
1. Turn ignition switch “ON”. (Do not start engine.)
2. Check the voltage between the IPDM E/R connector and
ground.
OK or NG
OK >> GO TO 3.
NG >> GO TO 2.
2. DETECT MALFUNCTIONING ITEM
Check the following items:

Starter relay, Refer to SC-10, "STARTING SYSTEM" .

IPDM E/R, Refer to PG-17, "IPDM E/R (INTELLIGENT POWER DISTRIBUTION MODULE ENGINE
ROOM)" .

Disconnections or short-circuits in the harness between TCM and IPDM E/R.
OK or NG
OK >> GO TO 3.
NG >> Repair or replace damaged parts.
3. CHECK TCM
Perform TCM input/output signals inspection. Refer to AT- 9 0 , "
TCM Input/Output Signal Reference Values" .
OK or NG
OK >> GO TO 5.
NG >> GO TO 4.
4. DETECT MALFUNCTIONING ITEM
Check the following items:

Power supply and ground circuit for TCM.

The A/T assembly harness connector terminals for damage or loose connection with harness connector.
OK or NG
OK >> GO TO 5.
NG >> Repair or replace damaged parts.
Item name Condition Display value
STARTER RELAYSelector lever in N, P position. ON
Selector lever in other position. OFF
PCIA0056E
Item ConnectorTe r m i n a l
(Wirer color)Shift position Voltage (Approx.)
Sta rte r
relayE12248
(B/R)GroundN and P Battery voltage
R, D and M 0V
LCIA0320E

ATC-18
REFRIGERATION SYSTEM
Revision: August 20072004 QX56
REFRIGERATION SYSTEMPFP:KA990
Refrigerant CycleEJS002BS
REFRIGERANT FLOW
The refrigerant flows in the standard pattern, that is, through the compressor, the condenser with liquid tank,
through the front and rear evaporators, and back to the compressor. The refrigerant evaporation through the
evaporator coils are controlled by front and rear externally equalized expansion valves, located inside the front
and rear evaporator cases.
Refrigerant System ProtectionEJS002BT
REFRIGERANT PRESSURE SENSOR
The refrigerant system is protected against excessively high or low pressures by the refrigerant pressure sen-
sor, located on the condenser. If the system pressure rises above or falls below the specifications, the refriger-
ant pressure sensor detects the pressure inside the refrigerant line and sends a voltage signal to the ECM.
The ECM deenergizes the A/C relay to disengage the magnetic compressor clutch when pressure on the high
pressure side detected by refrigerant pressure sensor is over about 2,746 kPa (28 kg/cm
2 , 398 psi), or below
about 120 kPa (1.22 kg/cm
2 , 17.4 psi).

AIR CONDITIONER CONTROL
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MAGNET CLUTCH CONTROL
When the A/C or DEF switch is activated, the front air control outputs a compressor ON signal to the BCM.
Upon receiving this input, the BCM sends a compressor ON signal to the ECM via CAN communication lines.
The ECM then judges whether the compressor can be turned ON, based on each sensor status (refrigerant
pressure sensor signal, throttle angle sensor, etc.). If it determines the compressor can be turned ON, a com-
pressor ON signal is sent to the IPDM E/R via CAN communication lines.
Upon receipt of a compressor ON signal, the IPDM E/R turns ON the A/C relay which engages the magnet
clutch and operates the A/C compressor.
SELF-DIAGNOSTIC SYSTEM
A self-diagnostic system is built into the front air control to quickly locate the cause of symptoms. Refer to
ATC-53, "
A/C System Self-diagnosis Function"
WJIA0751E

ATC-86
TROUBLE DIAGNOSIS
Revision: August 20072004 QX56
1. CHECK FUSES
Check 20A fuses [No. 24 and 27 (located in the fuse and fusible link box)]. For fuse layout. Refer to PG-77,
"FUSE AND FUSIBLE LINK BOX" .
OK or NG
OK >> GO TO 2.
NG >> GO TO 10.
2. CHECK FRONT BLOWER MOTOR POWER SUPPLY CIRCUIT
1. Turn ignition switch OFF.
2. Disconnect front blower motor connector M62.
3. Turn ignition switch ON.
4. Press the MODE switch to select any mode except OFF.
5. Set front fan switch to high.
6. Check voltage between front blower motor harness connector
M62 terminal 2 (W/L) and ground.
OK or NG
OK >> GO TO 12.
NG >> GO TO 3.
3. CHECK FRONT BLOWER MOTOR RELAY (SWITCH SIDE) POWER SUPPLY CIRCUIT
1. Turn ignition switch OFF.
2. Disconnect front blower motor relay M107.
3. Check voltage between front blower motor relay harness con-
nector M107 terminals 5 (GR) and 7 (P), and ground.
OK or NG
OK >> GO TO 4.
NG >> Repair harness or connector.
4. CHECK FRONT BLOWER MOTOR RELAY
Refer to ATC-89, "
Front Blower Motor Relay" .
OK or NG
OK >> GO TO 5.
NG >> Replace front blower motor relay.
5. CHECK FRONT BLOWER MOTOR RELAY (SWITCH SIDE) CIRCUIT FOR OPEN
1. Turn ignition switch OFF.
2. Disconnect blower motor relay connector M107 and front blower
motor connector M62.
3. Check continuity between front blower motor relay harness con-
nector M107 terminals 3 (W/L) and 6 (W/L)
and front blower motor harness connector M62 terminal 2 (W/L).
OK or NG
OK >> GO TO 6.
NG >> Repair harness or connector.2 - Ground : Battery voltage should exist.
WJIA1331E
5, 7 - Ground : Battery voltage should exist.
WJIA0780E
3, 6 - 2 : Continuity should exist.
WJIA0781E

TROUBLE DIAGNOSIS
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6. CHECK VARIABLE BLOWER CONTROL POWER SUPPLY CIRCUIT FOR OPEN
1. Disconnect variable blower control connector M122.
2. Check continuity between front blower motor relay harness con-
nector M107 terminals 3 (W/L) and 6 (W/L), and variable blower
control harness connector M122 terminal 1 (W/L).
OK or NG
OK >> GO TO 7.
NG >> Repair harness or connector.
7. CHECK VARIABLE BLOWER CONTROL SIGNAL CIRCUIT
1. Disconnect front air control connector M49.
2. Check continuity between front air control harness connector
M49 terminal 13 (G/R) and variable blower control harness con-
nector M122 terminal 2 (G/R).
OK or NG
OK >> GO TO 8.
NG >> Repair harness or connector.
8. CHECK FRONT BLOWER MOTOR RELAY (COIL SIDE) POWER SUPPLY
1. Turn ignition switch ON.
2. Check voltage between front blower motor relay harness con-
nector M107 terminal 1 (Y/G) and ground.
OK or NG
OK >> GO TO 9.
NG >> Repair harness or connector.
9. CHECK FRONT BLOWER MOTOR RELAY (COIL SIDE) GROUND CIRCUIT
1. Turn ignition switch OFF.
2. Check continuity between front blower motor relay harness con-
nector M107 terminal 2 (R/B) and front air control harness con-
nector M49 terminal 26 (R/B).
OK or NG
OK >> Replace front air control. Refer to ATC-135, "FRONT
AIR CONTROL" .
NG >> Repair harness or connector.3, 6 - 1 : Continuity should exist.
WJIA0784E
13 - 2 : Continuity should exist.
WJIA0785E
1 - Ground : Battery voltage should exist.
WJIA0786E
2 - 26 : Continuity should exist.
WJIA0471E

TROUBLE DIAGNOSIS
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COMPONENT INSPECTION
Front Blower Motor Relay
Check continuity between terminals by supplying 12 volts and
ground to coil side terminals of relay.
Front Blower Motor
Confirm smooth rotation of the blower motor.

Ensure that there are no foreign particles inside the blower unit.

Apply 12 volts to terminal 2 and ground to terminal 1 and verify
that the motor operates freely and quietly.
LJIA0068E
WJIA0895E