AT-78
[RE4F04B]
TROUBLE DIAGNOSIS - BASIC INSPECTION
Revision: November 2006
2006 Altima
5.
Start engine and measure line pressure at idle and stall speed.
●
When measuring line pressure at stall speed, follow the
stall test procedure.
JUDGEMENT OF LINE PRESSURE TEST
Road Test
ECS0096C
DESCRIPTION
●
The purpose of the test is to determine overall performance of A/
T and analyze causes of problems.
●
The road test consists of the following three parts:
1.
Check before engine is started
2.
Check at idle
3.
Cruise test
SAT493G
Judgement
Suspected parts
At idle
Line pressure is low in all positions.
●
Oil pump wear
●
Control piston damage
●
Pressure regulator valve or plug sticking
●
Spring for pressure regulator valve damaged
●
Fluid pressure leakage between oil strainer and pres-
sure regulator valve
●
Clogged strainer
Line pressure is low in particular position.
●
Fluid pressure leakage between manual valve and par-
ticular clutch
●
For example, line pressure is:
−
Low in R and 1 positions, but
−
Normal in D and 2 positions.
Therefore, fluid leakage exists at or around low and
reverse brake circuit.
Refer to
AT-27, "CLUTCH AND BAND CHART"
Line pressure is high.
●
A/T fluid temperature sensor damaged
●
Line pressure solenoid valve sticking
●
Short circuit of line pressure solenoid valve circuit
●
Pressure modifier valve sticking
●
Pressure regulator valve or plug sticking
●
Open in dropping resistor circuit
At stall speed
Line pressure is low.
●
Line pressure solenoid valve sticking
●
Short circuit of line pressure solenoid valve circuit
●
Pressure regulator valve or plug sticking
●
Pressure modifier valve sticking
●
Pilot valve sticking
SAT786A