Dtc P0756 Shift Solenoid B Performance Without Input Speed - Isuzu Trooper 1999 Workshop Manual

7A1–68 TRANSMISSION CONTROL SYSTEM (4L30–E)

DTC P0756 Shift Solenoid B Performance Without Input Speed

Circuit Description
The shift solenoid B is used to control fluid flow acting on
the 2–3 shift valves. The solenoid is a normally open
exhaust valve that is used with the shift solenoid (A) to
allow four different shift combinations.
This DTC detects a non 2–3 upshift and a non 1st gear
when 1st gear is commanded, or 1st gear when 4th gear
is commanded. This is a type "B" DTC.
Conditions For Setting The DTC
f No TPS DTCs P0122 or P0123.
f No OSS DTCs P0722 or P0723.
f No TCC solenoid DTC P0742, P1860.
f No shift solenoid DTCs P0753, P0758.
f Vehicle speed is greater than 10 km/h (6.25 mph).
f Gear range is D4.
f Engine vacuum is between 0 and 70 kPa.
f Engine speed is less than 6,000 rpm.
f Transmission fluid temperature is between 20° and
125°C (68° and 257°F).
f TCC is "off".
All of the above conditions have been met and either one
of the following fail conditions occurs:
f The solenoid is stuck "on" and conditions 3 and 4 are
present two consecutive times.
f The solenoid is stuck "off" and conditions 1 and 3 are
present two consecutive times.
Condition 1:
f TP angle is greater than 45%.
f 1st gear is commanded for 3 seconds.
f Speed ratio is between 0.5 and 2.65 (speed ratio is
engine speed output speed).
f Transmission output speed is between 320 and 2,000
rpm.
f TCC slip speed is between –200 and –4,000 rpm for
1.8 seconds.
Condition 2:
f Not used.
Condition 3:
f Commanded 2–3 shift.
f TP angle is between 10 and 60%.
f TP angle is within +/–5%.
f 3rd gear is commanded for 2 seconds.
f 3rd gear speed ratio is greater than the last 2nd gear
speed ratio minus 0.05.
f 3rd gear TCC slip speed is greater than or equal to the
last 2nd gear TCC slip speed plus 520 rpm for 1.8
seconds.
f Discontinue test if time since shift commanded is 5.57
seconds.
Condition 4:
f TP angle is greater than 10%.
f 4th gear is commanded for 1 second.
f Speed ratio is between 2.0 and 4.0.
f Transmission output speed is between 0 and 8,192
rpm.
f TCC slip speed is between 2,000 and 5,000 rpm for 3
seconds.
Action Taken When the DTC Sets
f Maximum line pressure.
f The PCM will illuminate the Malfunction Indicator
Lamp (MIL) and CHECK TRANS LAMP.
Conditions For Clearing The MIL/DTC
f The PCM will turn off the MIL and CHECK TRANS
Lamp after three consecutive ignition cycles without a
failure reported.
f The DTC can be cleared from the PCM history by
using a scan tool.
D07RT011