ON BOARD DIAGNOSTIC (OBD) SYSTEM AT-39
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ON BOARD DIAGNOSTIC (OBD) SYSTEMPFP:00028
IntroductionACS002LN
The A/T system has two self-diagnostic systems.
The first is the emission-related on board diagnostic system (OBD-II) performed by the TCM in combination
with the ECM. The malfunction is indicated by the MIL (malfunction indicator lamp) and is stored as a DTC in
the ECM memory but not the TCM memory.
The second is the TCM original self-diagnosis indicated by the A/T CHECK indicator lamp. The malfunction is
stored in the TCM memory. The detected items are overlapped with OBD-II self-diagnostic items. For detail,
refer to AT- 9 3 , "
Display Items List" .
OBD-II Function for A/T SystemACS002LO
The ECM provides emission-related on board diagnostic (OBD-II) functions for the A/T system. One function
is to receive a signal from the TCM used with OBD-related parts of the A/T system. The signal is sent to the
ECM when a malfunction occurs in the corresponding OBD-related part. The other function is to indicate a
diagnostic result by means of the MIL (malfunction indicator lamp) on the instrument panel. Sensors, switches
and solenoid valves are used as sensing elements.
The MIL automatically illuminates in “One or Two Trip Detection Logic” when a malfunction is sensed in rela-
tion to A/T system parts.
One or Two Trip Detection Logic of OBD-IIACS002LP
ONE TRIP DETECTION LOGIC
If a malfunction is sensed during the first test drive, the MIL will illuminate and the malfunction will be stored in
the ECM memory as a DTC. The TCM is not provided with such a memory function.
TWO TRIP DETECTION LOGIC
When a malfunction is sensed during the first test drive, it is stored in the ECM memory as a 1st trip DTC
(diagnostic trouble code) or 1st trip freeze frame data. At this point, the MIL will not illuminate. — 1st trip
If the same malfunction as that experienced during the first test drive is sensed during the second test drive,
the MIL will illuminate. — 2nd trip
The “Trip” in the “One or Two Trip Detection Logic” means a driving mode in which self-diagnosis is performed
during vehicle operation.
OBD-II Diagnostic Trouble Code (DTC)ACS002LQ
HOW TO READ DTC AND 1ST TRIP DTC
DTC and 1st trip DTC can be read by the following methods.
( with CONSULT-II or GST) CONSULT-II or GST (Generic Scan Tool) Examples: P0705, P0720 etc.
These DTC are prescribed by SAE J2012.
(CONSULT-II also displays the malfunctioning component or system.)
1st trip DTC No. is the same as DTC No.
Output of the diagnostic trouble code indicates that the indicated circuit has a malfunction. How-
ever, in case of the Mode II and GST, they do not indicate whether the malfunction is still occurring
or occurred in the past and returned to normal.
CONSULT-II can identify them as shown below, therefore, CONSULT-II (if available) is recom-
mended.
A sample of CONSULT-II display for DTC and 1st trip DTC is shown
on the next page. DTC or 1st trip DTC of a malfunction is displayed
in SELF-DIAGNOSTIC RESULTS mode for “ENGINE” with CON-
SULT-II. Time data indicates how many times the vehicle was driven
after the last detection of a DTC.
BCIA0030E
AT-40
ON BOARD DIAGNOSTIC (OBD) SYSTEM
Revision: 2005 July 2005 FX
If the DTC is being detected currently, the time data will be “0”.
If a 1st trip DTC is stored in the ECM, the time data will be “1t”.
Freeze Frame Data and 1st Trip Freeze Frame Data
The ECM has a memory function, which stores the driving condition such as fuel system status, calculated
load value, engine coolant temperature, short term fuel trim, long term fuel trim, engine speed and vehicle
speed at the moment the ECM detects a malfunction.
Data which are stored in the ECM memory, along with the 1st trip DTC, are called 1st trip freeze frame data,
and the data, stored together with the DTC data, are called freeze frame data and displayed on CONSULT-II
or GST. The 1st trip freeze frame data can only be displayed on the CONSULT-II screen, not on the GST. For
detail, refer to EC-132, "
CONSULT-II Function (ENGINE)" (for VQ35DE) or EC-822, "CONSULT-II Function
(ENGINE)" (for VK45DE).
Only one set of freeze frame data (either 1st trip freeze frame data of freeze frame data) can be stored in the
ECM. 1st trip freeze frame data is stored in the ECM memory along with the 1st trip DTC. There is no priority
for 1st trip freeze frame data and it is updated each time a different 1st trip DTC is detected. However, once
freeze frame data (2nd trip detection/MIL on) is stored in the ECM memory, 1st trip freeze frame data is no
longer stored. Remember, only one set of freeze frame data can be stored in the ECM. The ECM has the fol-
lowing priorities to update the data.
Both 1st trip freeze frame data and freeze frame data (along with the DTC) are cleared when the ECM mem-
ory is erased.
HOW TO ERASE DTC
The diagnostic trouble code can be erased by CONSULT-II, GST or ECM DIAGNOSTIC TEST MODE as
described following.
If the battery cable is disconnected, the diagnostic trouble code will be lost within 24 hours.
When you erase the DTC, using CONSULT-II or GST is easier and quicker than switching the mode
selector on the ECM.
The following emission-related diagnostic information is cleared from the ECM memory when erasing DTC
related to OBD-II. For details, refer to EC-55, "
Emission-Related Diagnostic Information" (for VQ35DE) or EC-
746, "Emission-Related Diagnostic Information" (for VK45DE).
Diagnostic trouble codes (DTC)
SAT015K
SAT016K
Priority Items
1 Freeze frame data Misfire — DTC: P0300 - P0306
Fuel Injection System Function — DTC: P0171, P0172, P0174, P0175
2 Except the above items (Includes A/T related items)
3 1st trip freeze frame data
ON BOARD DIAGNOSTIC (OBD) SYSTEM AT-41
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1st trip diagnostic trouble codes (1st trip DTC)
Freeze frame data
1st trip freeze frame data
System readiness test (SRT) codes
Test values
HOW TO ERASE DTC (WITH CONSULT-II)
If a DTC is displayed for both ECM and TCM, it is necessary to be erased for both ECM and TCM.
1. If the ignition switch stays ON after repair work, be sure to turn ignition switch OFF once. Wait at least 10 seconds and then turn it ON (engine stopped) again.
2. Turn CONSULT-II ON and touch “A/T”.
3. Touch “SELF-DIAG RESULTS”.
4. Touch “ERASE”. (The DTC in the TCM will be erased.) Then touch “BACK” twice.
5. Touch “ENGINE”.
6. Touch “SELF-DIAG RESULTS”.
7. Touch “ERASE”. (The DTC in the ECM will be erased.)
SCIA5671E
TROUBLE DIAGNOSIS AT-43
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TROUBLE DIAGNOSISPFP:00004
DTC Inspection Priority ChartACS002LS
If some DTCs are displayed at the same time, perform inspections one by one based on the following priority
chart.
NOTE:
If DTC U1000 is displayed with other DTCs, first perform the trouble diagnosis for DTC U1000. Refer to
AT- 1 0 6
.
Fail-safeACS002LT
The TCM has an electrical fail-safe mode. This mode makes it possible to operate even if there is a an error in
a main electronic control input/output signal circuit.
In fail-safe mode, even if the selector lever is “D” or “M” mode, the transmission is fixed in 2nd, 4th or 5th
(depending on the breakdown position), so the customer should feel “slipping” or “poor acceleration”. When
fail-safe mode is triggered, when the ignition switch is switched “ON”, the A/T CHECK indicator lamp flashes
for about 8 seconds. (Refer to AT- 1 0 3 , "
TCM SELF-DIAGNOSTIC PROCEDURE (NO TOOLS)" ).
Even when the electronic circuits are normal, under special conditions (for example, when slamming on the
brake with the wheels spinning drastically and stopping the tire rotation), the transmission can go into fail-safe
mode. If this happens, switch OFF the ignition switch for 10 seconds, then switch it ON again to return to the
normal shift pattern. Also, the A/T CHECK indicator lamp flashes for about 8 seconds once, then is cleared.
Therefore, the customer's vehicle has returned to normal, so handle according to the “WORK FLOW” (Refer to
AT- 4 6
).
FAIL-SAFE FUNCTION
If any malfunction occurs in a sensor or solenoid, this function controls the A/T to mark driving possible.
Vehicle Speed Sensor
Signals are input from two systems - from vehicle speed sensor A/T (revolution sensor) installed on the
transmission and from combination meter so normal driving is possible even if there is a malfunction in
one of the systems. And if vehicle speed sensor A/T (revolution sensor) has unusual cases, 5th gear and
manual mode are prohibited.
Accelerator Pedal Position Sensor
If there is a malfunction in one of the systems, the accelerator opening angle is controlled by ECM accord-
ing to a pre-determined accelerator angle to make driving possible. And if there are malfunctions in tow
systems, the engine speed is fixed by ECM to a pre-determined engine speed to make driving possible.
Throttle Position Sensor
If there is a malfunction in one of the systems, the accelerator opening angle is controlled by ECM accord-
ing to a pre-determined accelerator angle to make driving possible. And if there are malfunctions in tow
systems, the accelerator opening angle is controlled by the idle signal sent from the ECM which is based
on input indicating either idle condition or off-idle condition (pre-determined accelerator opening) in order
to make driving possible.
PNP Switch
In the unlikely event that a malfunction signal enters the TCM, the position indicator is switched OFF, the
starter relay is switched OFF (starter starting is disabled), the back-up lamp relay switched OFF (back-up
lamp is OFF) and the position is fixed to the “D” position to make driving possible.
Starter Relay
The starter relay is switched OFF. (Starter starting is disabled.)
Priority Detected items (DTC)
1 U1000 CAN communication line
2 Except above
AT-44
TROUBLE DIAGNOSIS
Revision: 2005 July 2005 FX
A/T Interlock
If there is an A/T interlock judgment malfunction, the transmission is fixed in 2nd gear to make driving pos-
sible.
NOTE:
When the vehicle is driven fixed in 2nd gear, a turbine revolution sensor malfunction is displayed,
but this is not a turbine revolution sensor malfunction.
When the coupling pattern below is detected, the fail-safe action corresponding to the pattern is per-
formed.
A/T INTERLOCK COUPLING PATTERN TABLE
: NG X: OK
A/T 1st Engine Braking
When there is an A/T first gear engine brake judgment malfunction, the low coast brake solenoid is
switched OFF to avoid the engine brake operation.
Line Pressure Solenoid
The solenoid is switched OFF and the line pressure is set to the maximum hydraulic pressure to make
driving possible.
Torque Converter Clutch Solenoid
The solenoid is switched OFF to release the lock-up.
Low Coast Brake Solenoid
When a (electrical or functional) malfunction occurs, in order to make driving possible, if the solenoid is
ON, the transmission is held in 2nd gear; if the solenoid is OFF, the transmission is held in 4th gear.
(Engine brake is not applied in 1st and 2nd gear.)
Input Clutch Solenoid
If a (electrical or functional) malfunction occurs with the solenoid either ON or OFF, the transmission is
held in 4th gear to make driving possible.
Direct Clutch Solenoid
If a (electrical or functional) malfunction occurs with the solenoid either ON or OFF, the transmission is
held in 4th gear to make driving possible.
Front Brake Solenoid
If a (electrical or functional) malfunction occurs with the solenoid ON, in order to make driving possible,
the A/T is held in 5th gear; if the solenoid is OFF, 4th gear.
High and Low Reverse Clutch Solenoid
If a (electrical or functional) malfunction occurs with the solenoid either ON or OFF, the transmission is
held in 4th gear to make driving possible.
Turbine Revolution Sensor 1 or 2
The control is the same as if there were no turbine revolution sensors, 5th gear and manual mode are pro-
hibited.
Gear position ATF pressure switch output
Fail-safe function Clutch pressure output pattern after fail-safe func-
tion
SW3 (I/C) SW6
(HLR/ C) SW5
(D/C) SW1
(FR/B) SW2
(LC/B) I/C HLR/C D/C FR/B LC/B L/U
A/T inter-
lock cou-
pling pattern 3rd – X X –
Held in
2nd gear OFF OFF ON OFF OFF OFF
4th – X X – Held in
2nd gear OFF OFF ON OFF OFF OFF
5th X X – X Held in
2nd gear OFF OFF ON OFF OFF OFF
AT-90
TROUBLE DIAGNOSIS
Revision: 2005 July 2005 FX
CONSULT-II Function (A/T)ACS002M9
CONSUT-II can display each diagnostic item using the diagnostic test models shown following.
FUNCTION
CONSULT-II REFERENCE VALUE
NOTICE:
1. The CONSULT-II electrically displays shift timing and lock-up timing (that is, operation timing of each sole-
noid).
Check for time difference between actual shift timing and the CONSULT-II display. If the difference is
noticeable, mechanical parts (except solenoids, sensors, etc.) may be malfunctioning. Check mechanical
parts using applicable diagnostic procedures.
2. Shift schedule (which implies gear position) displayed on CONSULT-II and that indicated in Service Man- ual may differ slightly. This occurs because of the following reasons:
–Actual shift schedule has more or less tolerance or allowance,
–Shift schedule indicated in Service Manual refers to the point where shifts start, and
–Gear position displayed on CONSULT-II indicates the point where shifts are completed.
3. Display of solenoid valves on CONSULT-II changes at the start of shifting, while gear position is displayed upon completion of shifting (which is computed by TCM).
Diagnostic test mode Function Reference page
Self-diagnostic results Self-diagnostic results can be read and erased quickly. AT- 9 3
Data monitor Input/Output data in the ECU can be read.AT- 9 6
CAN diagnostic support
monitor The results of transmit/receive diagnosis of CAN communication can be read.
AT- 1 0 0
Function test Performed by CONSULT-II instead of a technician to determine whether each system
is “OK” or “NG”. —
DTC work support Select the operating condition to confirm Diagnosis Trouble Codes. AT- 1 0 0
ECU part number ECU part number can be read. —
Item name Condition Display value
(Approx.)
VHCL/S SE·A/T During driving Approximately
matches the speed-
ometer reading.
VHCL/S SE·MTR
ACCELE POSI Released accelerator pedal. 0.0/8
Fully depressed accelerator pedal. 8/8
CLSD THL POS Released accelerator pedal. ON
Fully depressed accelerator pedal. OFF
W/O THL POS Fully depressed accelerator pedal. ON
Released accelerator pedal. OFF
BRAKE SW Depressed brake pedal. ON
Released brake pedal. OFF
ENGINE SPEED Engine running Closely matches the
tachometer reading.
TURBINE REV During driving (lock-up ON) Approximately
matches the engine
speed.
ATF TEMP SE 1 0 °C (32 ° F) - 20 °C (68 °F) - 80 °C (176 °F) 3.3 - 2.7 - 0.9 V
ATF TEMP SE 2 3.3 - 2.5 - 0.7 V
TCC SOLENOID When performing slip lock-up 0.2 - 0.4 A
When performing lock-up 0.4 - 0.6 A
LINE PRES SOL During driving 0.2 - 0.6 A
TROUBLE DIAGNOSIS AT-91
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FR/B SOLENOID Front brake engaged. Refer to
AT- 2 1 . 0.6 - 0.8 A
Front brake disengaged. Refer to AT- 2 1
. 0 - 0.05 A
I/C SOLENOID Input clutch disengaged. Refer to
AT- 2 1
. 0.6 - 0.8 A
Input clutch engaged. Refer to AT- 2 1
. 0 - 0.05 A
D/C SOLENOID Direct clutch disengaged. Refer to
AT- 2 1
. 0.6 - 0.8 A
Direct clutch engaged. Refer to AT- 2 1
. 0 - 0.05 A
HLR/C SOL High and low reverse clutch disengaged. Refer to
AT- 2 1
. 0.6 - 0.8 A
High and low reverse clutch engaged. Refer to AT- 2 1
. 0 - 0.05 A
STARTER RELAY Selector lever in “N”, “P” position. ON
Selector lever in other positions. OFF
SLCT LVR POSI Selector lever in “N”,“P” position. N/P
Selector lever in “R” position. R
Selector lever in “D” position. D
ON OFF SOL Low coast brake engaged. Refer to
AT- 2 1
.ON
Low coast brake disengaged. Refer to AT- 2 1
.OFF
ATF PRES SW 1 Front brake engaged. Refer to
AT- 2 1
.ON
Front brake disengaged. Refer to AT- 2 1
.OFF
ATF PRES SW 2 Low coast brake engaged. Refer to
AT- 2 1
.ON
Low coast brake disengaged. Refer to AT- 2 1
.OFF
ATF PRES SW 3 Input clutch engaged. Refer to
AT- 2 1
.ON
Input clutch disengaged. Refer to AT- 2 1
.OFF
ATF PRES SW 5 Direct clutch engaged. Refer to
AT- 2 1
.ON
Direct clutch disengaged. Refer to AT- 2 1
.OFF
ATF PRES SW 6 High and low reverse clutch engaged. Refer to
AT- 2 1
.ON
High and low reverse clutch disengaged Refer to AT- 2 1
.OFF
MANU MODE SW Manual shift gate position (neutral) ON
Other than the above OFF
NON M-MODE SW Manual shift gate position OFF
Other than the above ON
UP SW LEVER Selector lever: + side ON
Other than the above OFF
DOWN SW LEVER Selector lever: - side ON
Other than the above OFF
GEAR During driving 1, 2, 3, 4, 5 Item name Condition
Display value
(Approx.)
TROUBLE DIAGNOSIS AT-93
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SELF-DIAGNOSTIC RESULT MODE
After performing AT- 9 3 , "SELF-DIAGNOSTIC RESULT MODE" , place check marks for results on the AT- 4 7 ,
"DIAGNOSTIC WORKSHEET" . Reference pages are provided following the items.
Operation Procedure
1. Perform “CONSULT-II SETTING PROCEDURE”. Refer to AT- 9 2 , "CONSULT-II SETTING PROCEDURE"
.
2. Touch “SELF-DIAG RESULTS”. Display shows malfunction experienced since the last erasing
operation.
Display Items List
X: Applicable, —: Not applicable
BCIA0031E
Items (CONSULT-II
screen terms) Malfunction is detected when... TCM self-
diagnosis OBD-II
(DTC)
Reference page
“A/T” with
CONSULT- II MIL indica-
tor lamp*1, “ENGINE”
with CON- SULT-II or GST
CAN COMM CIR-
CUIT
When a malfunction is detected in CAN communications U1000 U1000 AT- 1 0 6
STARTER RELAY/
CIRC
If this signal is ON other than in “P” or “N” position, this is judged
to be a malfunction.
(And if it is OFF in “P” or “N” position, this too is judged to be a
malfunction.) P0615 —
AT- 1 0 9
TCMTCM is malfunctioning P0700 P0700*3 AT- 11 3
PNP SW/CIRC
PNP switch 1-4 signals input with impossible pattern
“P” position is detected from “N” position without any other posi-
tion being detected in between. P0705 P0705
AT- 11 4
VEH SPD SEN/CIR
AT (Revolution
sensor)
Signal from vehicle speed sensor A/T (Revolution sensor) not
input due to cut line or the like
Unexpected signal input during running
After ignition switch is turned ON, unexpected signal input from
vehicle speed sensor MTR before the vehicle starts moving P0720 P0720
AT- 11 8
ENGINE SPEED
SIGTCM does not receive the CAN communication signal from the
ECM. P0725 P0725*3
AT- 1 2 3
TCC SOLENOID/
CIRCNormal voltage not applied to solenoid due to cut line, short, or
the like P0740 P0740
AT- 1 2 5
A/T TCC S/V
FNCTNA/T cannot perform lock-up even if electrical circuit is good.
TCM detects as irregular by comparing difference value with slip
rotation. P0744 P0744*2
AT- 1 2 7
L/PRESS SOL/
CIRC
Normal voltage not applied to solenoid due to cut line, short, or
the like
TCM detects as irregular by comparing target value with monitor
value. P0745 P0745
AT- 1 2 9
TCM·RAMTCM memory (RAM) is malfunctioning. P1702 — AT- 1 3 1