7B1-10 AUTOMATIC TRANSMISSION (4 A/T)
Automatic Transmission Diagnostic Flow Table
Refer to the following pages for the details of each step.
Step Action Yes No
1 Customer Complaint Analysis
1) Perform customer complaint analysis refer-
ring to the next page.
Was customer complaint analysis performed
according to instruction?Go to Step 2. Perform customer com-
plaint analysis.
2 Diagnostic Trouble Code (DTC) and Freeze
Frame Data Check, Record and Clearance
1) Check for DTC (including pending DTC)
Is there any DTC(s)?Print DTC and freeze
frame data or write them
down and clear them by
referring to “DTC CLEAR-
ANCE” in this section
Go to Step 3.Go to Step 4.
3 Visual Inspection
1) Perform visual inspection referring to the
next page.
Is there any faulty condition?Repair or replace mal-
function part.
Go to Step 11.Go to Step 5.
4 Visual Inspection
1) Perform visual inspection referring to the
next page.
Is there any faulty condition?Go to Step 8.
5 Trouble Symptom Confirmation
1) Confirm trouble symptom referring to the
next page.
Is trouble symptom identified?Go to Step 6. Go to Step 7.
6 Rechecking and Record of DTC/Freeze Frame
Data
1) Recheck for DTC and freeze frame data
referring to “DTC Check” in this section.
Is there any DTC(s)?Go to Step 9. Go to Step 8.
7 Rechecking and Record of DTC/Freeze Frame
Data
1) Recheck for DTC and freeze frame data
referring to “DTC Check” in this section.
Is there any DTC(s)?Go to Step 9. Go to Step 10.
8 Automatic Transmission Basic Inspection and
Trouble Diagnosis Table
1) Check and repair according to “A/T Basic
Check” and “Trouble Diagnosis Table” in this
section.
Are check and repair complete?Go to Step 11. Check and repair mal-
function part(s).
Go to Step 11.
9 Troubleshooting for DTC
1) Check and repair according to applicable
DTC diag. flow Table.
Are check and repair complete?
10 Check for Intermittent Problems
1) Check for intermittent problems referring to
the next page.
Is there any faulty condition?Repair or replace mal-
function part(s).
Go to Step 11.Go to Step 11.
AUTOMATIC TRANSMISSION (4 A/T) 7B1-11
STEP 1. CUSTOMER COMPLAINT ANALYSIS
Record details of the problem (failure, complaint) and how it occurred as described by the customer.
For this purpose, use of such a inspection form will facilitate collecting information to the point required for
proper analysis and diagnosis.
STEP 2. DIAGNOSTIC TROUBLE CODE (DTC)/FREEZE FRAME DATA CHECK, RECORD AND
CLEARANCE
First, referring to DTC check section, check DTC (including pending DTC). If DTC exists, print or write down
DTC and freeze frame data and then clear them by referring to DTC clearance section. DTC indicates malfunc-
tion in the system but it is not possible to know from it whether the malfunction is occurring now or it occurred in
the past and normal condition has been restored. In order to know that, check symptom in question according to
Step 5 and then recheck DTC according to Step 6.
Diagnosing a trouble based on the DTC in this step only or failure to clear the DTC in this step may result in an
faulty diagnosis, trouble diagnosis of a normal circuit or difficulty in troubleshooting which is otherwise unneces-
sary.
STEP 3 and STEP 4. VISUAL INSPECTION
As a preliminary step, be sure to perform visual check of the items that support proper function of the A/T and
engine referring to Visual Inspection section.
STEP 5. TROUBLE SYMPTOM CONFIRMATION
Check trouble symptoms based on information obtained in Step 1 “CUSTOMER COMPLAINT ANALYSIS” and
Step 2 “DTC/FREEZE FRAME DATA CHECK”.
Also, recheck DTC according to “DTC CONFIRMATION PROCEDURE” described in each “DTC FLOW
TABLE”.
STEP 6 and STEP 7. RECHECKING AND RECORD OF DTC/FREEZE FRAME DATA
Refer to “DTC CHECK” in this section for checking procedure.
STEP 8. A/T BASIC CHECK AND TROUBLE DIAGNOSIS TABLE
Perform A/T basic check according to the “A/T Basic Check Flow Table” first. When the end of the flow table has
been reached, check the parts of the system suspected as a possible cause referring to “TROUBLE DIAGNO-
SIS TABLE” and based on symptoms appearing on the vehicle (symptoms obtained through steps of customer
complaint analysis, trouble symptom confirmation and/or A/T basic check) and repair or replace faulty parts, if
any.
STEP 9. DIAGNOSTIC TROUBLE CODE FLOW TABLE
Based on the DTC indicated in Step 6 and 7 and referring to “DIAGNOSTIC TROUBLE CODE FLOW TABLE” in
this section, locate the cause of the trouble, namely in a sensor, switch, wire harness, connector, actuator, PCM
or other part and repair or replace faulty parts.11 Final Confirmation Test
1) Clear DTC if any.
2) Perform final confirmation test referring to
the next page.
Is there any problem symptom, DTC or abnor-
mal condition?Go to Step 6. End. Step Action Yes No
7B1-12 AUTOMATIC TRANSMISSION (4 A/T)
STEP 10. CHECK FOR INTERMITTENT PROBLEM
Check parts where an intermittent trouble is easy to occur (e.g., wire harness, connector, etc.), referring to
“INTERMITTENT AND POOR CONNECTION” in Section 0A and related circuit of DTC recorded in Step 2.
STEP 11. FINAL CONFIRMATION TEST
Confirm that the problem symptom has gone and the A/T is free from any abnormal conditions.
If what has been repaired is related to the malfunction DTC, clear the DTC once, set conditions under which
DTC was detected and A/T and/or vehicle was repaired and confirm that no DTC is indicated.
CUSTOMER PROBLEM INSPECTION FORM (EXAMPLE)
NOTE:
The above form is a standard sample. It should be modified according to conditions characteristic of
each market.
AUTOMATIC TRANSMISSION (4 A/T) 7B1-15
Trouble Diagnosis Table 1
Trouble Diagnosis Table 2
TRANSMISSION FLUID
RUNNING CONDITION
4 Perform stall test, time rag test, line pressure test,
engine brake test and “P” range test referring to
“STALL TEST”, “LINE PRESSURE TEST”, “ENGINE
BRAKE TEST” and ““P” RANGE TEST” in this section.
Are the test results satisfactory?Go to Step 5. Proceed to “TROUBLE
DIAGNOSIS TABLE 3” in
this section.
5 Proceed to “TROUBLE DIAGNOSIS TABLE 2” in this
section.
Is trouble identified?Repair or replace
defective parts.Proceed to “TROUBLE
DIAGNOSIS TABLE 3” in
this section. Step Action Yes No
Condition Possible Cause Correction
TCC does not operateBrake pedal (stop lamp) switch or its circuit
faulty (H25 engine only)Refer to “DIAGNOSTIC FLOW
TABLE A-1” in this section.
4WD low switch or its circuit faulty
Engine coolant temp. sensor or its circuit faulty
Cruise control signal circuit faulty (if equipped)
Gear does not change
to 4thO/D off switch or its circuit faulty Refer to “DIAGNOSTIC FLOW
TABLE A-2” in this section.
4WD low switch or its circuit faulty
Engine coolant temp. sensor or its circuit faulty
Cruise control signal circuit faulty (if equipped)
Condition Possible Cause Correction
Low fluid pressureClogged oil pump strainer Wash strainer.
Malfunction of pressure regulator valve Overhaul valve body.
High fluid pressurePressure regulator valve Overhaul valve body.
Condition Possible Cause Correction
Unable to run in all
rangeRegulator valve stick Replace.
Clogged oil strainer Wash strainer.
Seized or broken planetary gear Repair or replace.
Faulty manual valve Replace.
Poor 1st speed run-
ning or excessive slip-
page in “D” or “2”Faulty 1–2 shift valve Replace.
AUTOMATIC TRANSMISSION (4 A/T) 7B1-31
REFERENCE
Connect oscilloscope between C51-1-11 (+) and C51-1-10 (–) of
PCM connector connected to PCM and check input speed sensor
signal. 4 Check visually input speed sensor and over-
drive clutch drum for the followings.
•No damage
•No foreign material attached
•Correct installation
Are they in good condition?Intermittent trouble or
faulty PCM.
Check for intermittent
referring to “INTERMIT-
TENT AND POOR CON-
NECTION” in Section 0A.Clean, repair or replace. Step Action Yes No
[A] : Oscilloscope waveforms at specified idle speed in “p” range
AUTOMATIC TRANSMISSION (4 A/T) 7B1-33
TROUBLESHOOTING
REFERENCE
Connect oscilloscope between C51-1-23 (+) and C51-1-22 (–) of
PCM connector connected to PCM and check output speed sen-
sor signal. Step Action Yes No
1Was “A/T DIAGNOSTIC FLOW TABLE” in this
section performed?Go to Step 2. Go to “A/T DIAGNOSTIC
FLOW TABLE” in this sec-
tion.
2 Output shaft speed sensor circuit check :
1) Remove PCM cover.
2) With ignition switch OFF, disconnect PCM
connectors.
3) Check for proper connection to output
speed sensor at C51-1-22 and C51-1-23
terminals.
4) If OK, check resistance of sensor circuit.
Resistance between C51-1-22 and C51-1-23 :
387 – 473 Ω
ΩΩ Ω (at 20 °C (68 °F))
Resistance between C51-1-22/C51-1-23 and
ground :
1 MΩ
ΩΩ Ω or more
Are check results satisfactory?Go to Step 4. Go to Step 3.
3 Output shaft speed sensor check :
1) With ignition switch OFF, disconnect output
shaft speed sensor connector.
2) Check for proper connection to output shaft
speed sensor at each terminals.
3) If OK, then check resistance of output shaft
speed sensor.
Are measured values as specified in Step 2?“ORN” or “WHT” wire
open or shorted to
ground.Replace output shaft
speed sensor.
4 Check visually output shaft speed sensor and
sensor rotor for the followings.
•No damage
•No foreign material attached
•Correct installation
Are they in good condition?Intermittent trouble or
faulty PCM.
Check for intermittent
referring to “INTERMIT-
TENT AND POOR CON-
NECTION” in Section 0A.Clean, repair or replace.
[A] : Oscilloscope waveforms at about 40 km/h (25 mile/h)
DIFFERENTIAL (FRONT) 7E-3
Diagnosis
Differential Assembly Diagnosis Table
4WD Control System Diagnostic Flow Table
Before performing the trouble diagnosis, check that the transfer and front differential are in good condition and
there is no air leakage from air hoses and the actuator. Refer to “4WD CONTROL SYSTEM INSPECTION” in
this section for air leakage.
Notes on system circuit inspection
•Be sure to read “PRECAUTIONS FOR ELECTRICAL CIRCUIT SERVICE” in Section 0A before circuit
inspection and observe what is written there.
•For system circuit, refer to the figure of “GENERAL DESCRIPTION” in this section.
•For terminal arrangement, refer to “4WD CONTROL CIRCUIT INSPECTION” in this section. Condition Possible Cause Correction
Gear noiseDeteriorated or water mixed lubricant Repair and replenish.
Inadequate or insufficient lubricant Repair and replenish.
Maladjusted backlash between bevel pinion and gear Adjust.
Improper tooth contact in the mesh between bevel pinion
and gearAdjust or replace.
Loose bevel gear securing bolts Replace or retighten.
Damaged side gear(s) or side pinion(s) Replace.
Bearing noise(Constant noise) Deteriorated or water mixed lubricant Repair and replenish.
(Constant noise) Inadequate or insufficientlubricant Repair and replenish.
(Noise while coasting) Damaged bearing(s) of bevel pinion Replace.
(Noise while turning) Damaged differential side bearing(s)
or axle bearing(s)Replace.
Oil leakageWorn or damaged oil seal Replace.
Excessive oil Adjust oil level.
Loose differential carrier bolts Replace or retighten.
2WD/4WD
switching errorDefective actuator Replace.
Abnormality in 4WD control system Inspect referring to “4WD
CONTROL SYSTEM DIAG-
NOSTIC FLOW TABLE”.
7E-4 DIFFERENTIAL (FRONT)
Flow table
Step Action Yes No
1 Turn ON ignition switch (but engine at stop) and
check malfunction indicator lamp.
Does lamp light up?Go to step 2. A trouble has occurred
at some place. Repair
it referring to
MALFUNCTION INDI-
CATOR LAMP
(“CHECK ENGINE”
LAMP) CHECK in
DIAGNOSIS of Sec-
tion 6.
2 Check 4WD switch circuit.
Turn ignition switch ON and check that voltage
between terminal C51-3-7 and terminal C51-3-17
(ground) is as follows.
When transfer shift lever is in N or 2H : 10 – 14 V
When transfer shift lever is in 4L or 4H : 0 – 1 V
Is the check result satisfactory?Go to step 3. Check 4WD switch
(refer to Section 7A),
“BLK/ORN” and “BLK”
circuits of 4WD switch.
If OK, substitute a
known-good ECM
(PCM) and recheck.
3 Check power supply.
1) Turn ignition switch ON.
2) Check voltage between C51-1-9 and C51-3-17
(ground). The check results should be as follows.
When transfer shift lever is in N or 2H : 0 – 1 V
When transfer shift lever is in 4L or 4H : 10 – 14 V
Is the check result satisfactory?Go to step 4. Check “RED” circuit. If
it is OK, substitute a
known-good ECM
(PCM) and recheck.
4 Check air pump assembly circuit.
1) Check for proper connection to air pump assem-
bly at all terminals.
2) Turn ignition switch ON.
3) Check voltage between C51-3-18 and C51-3-17
(ground). The check result should be as follows.
When transfer shift lever is in 2H or N : 0 – 1 V
When transfer shift lever is in 4L or 4H (more than
4 seconds after shifted to 4L or 4H) : 10 – 14 V
Is the check result satisfactory?Go to step 5. Check air pump
assembly referring to
“ON-VEHICLE SER-
VICE”, and then
“PNK” circuit.
If OK, substitute a
known-good ECM
(PCM) and recheck.
5 Check 4WD indicator lamp circuit.
1) Turn ignition switch ON.
2) Check voltage between E61-19 and C51-3-17
(ground). The check result should be as follows.
When transfer shift lever is in 2H or N : 10 – 14 V
When transfer shift lever is in 4L or 4H : 0 – 1 V
Is the check result satisfactory?4WD control system is
in good condition.Check “ORN/BLK” cir-
cuit (including indica-
tor lamp and
combination meter).
If OK, substitute a
known-good ECM
(PCM) and recheck.