ON-BOARD DIAGNOSTIC
K–79
K
Diagnostic procedure
STEP INSPECTION ACTION
1 VERIFY RELATED REPAIR INFORMATION
AVAILABILITY
• Check for related Service Bulletins availability.
• Is any related repair information available?
Yes Perform repair or diagnosis according to available repair
information.
• If vehicle is not repaired, go to next step.
No Go to next step.
2 CHECK ATF CONDITION
• Turn ignition key to OFF.
• Check ATF condition.
— Clear red: Normal
— Milky: Water mixed in fluid
— Reddish brown: Deteriorated ATF
• Is it okay?
(See K–12 Automatic Transaxle Fluid (ATF)
Condition Inspection.)
Yes Go to next step.
No If ATF color milky or reddish brown, replace ATF, then go to
Step 4.
(See K–13 AUTOMATIC TRANSAXLE FLUID (ATF)
REPLACEMENT.)
3 CHECK ATF LEVEL
• Start engine.
• Warm up ATX.
• Is ATF level within specification?
(See K–12 Automatic Transaxle Fluid (ATF) Level
Inspection.)
Yes Go to next step.
No Adjust ATF level, then go to Step 6.
(See K–12 Automatic Transaxle Fluid (ATF) Level
Inspection.)
4 INSPECT LINE PRESSURE
• Start engine.
• Measure line pressure.
Specification
Idle: 330—470 kPa {3.4—4.7 kgf/cm
2
, 49—66
psi}
Stall: 1,160—1,320 kPa {11.9—13.4 kgf/cm
2
,
170—190 psi}
• Is line pressure within specification?
(See K–6 Line Pressure Test.)
Yes Go to next step.
No • All ranges: Replace oil pump or control valve body, then
go to Step 6.
• Any ranges: Replace ATX, then go to Step 6.
(See K–29 AUTOMATIC TRANSAXLE REMOVAL/
INSTALLATION.)
(See ATX Workshop Manual FN4A-EL (9999-95-FN4A-
99).)
5 CHECK OPERATION OF EACH VALVE AND
EACH SPRING
• Turn ignition key to OFF.
• Remove control valve body.
• Disassemble control valve body.
• Is each valve operation okay and is return
spring okay?
(See K–34 CONTROL VALVE BODY REMOVAL,
K–35 CONTROL VALVE BODY INSTALLATION.)
(See ATX Workshop Manual FN4A-EL (9999-95-
FN4A-99).)
Yes Replace ATX, then go to next step.
(See K–29 AUTOMATIC TRANSAXLE REMOVAL/
INSTALLATION.)
(See ATX Workshop Manual FN4A-EL (9999-95-FN4A-
99).)
No Repair or replace shift valve and return spring, then go to
next step.
(See K–34 CONTROL VALVE BODY REMOVAL, K–35
CONTROL VALVE BODY INSTALLATION.)
(See ATX Workshop Manual FN4A-EL (9999-95-FN4A-
99).)
6 VERIFY TROUBLESHOOTING OF DTC P0742
COMPLETED
• Make sure to reconnect all disconnected
connectors.
• Clear DTC from memory using WDS or
equivalent.
• Start engine.
• Warm up engine and ATX.
• Drive vehicle under following.
— ATF temperature: 20 °C {68 °F} or above
— Drive in D range, 4th gear (TCC not in
operation)
— Vehicle speed: below 70 km/h {43 mph}.
• Throttle conditions
— Throttle opening angle (TP PID) above
10.1% and 5 seconds or more have
passed.
— Throttle opening angle (TP PID) within
3.1—10.1% and 3 seconds or more have
passed.
— Throttle opening angle at closed throttle
position and 5 seconds or more have
passed.
• Are any DTCs present?
Yes Replace PCM, then go to next step.
(See F–43 PCM REMOVAL/INSTALLATION.)
No Go to next step.