Holiday Navigator 2003 Owner's Manual page 433

The electronic control system of the transmission is programmed to inform the
operator of a problem with the transmission system and reacts automatically to
protect the operator, motorhome and transmission. When the Electronic Control
Unit (ECU) detects a DO NOT SHIFT (DNS) condition the ECU restricts shifting,
turns on the CHECK TRANS light in the instrument panel and registers a fault code.
NOTE: For some problems, fault codes may be registered
without the ECU activating the CHECK TRANS light. An
Allison Transmission authorized service outlet should be
consulted whenever there is a transmission related concern.
They have the equipment to check diagnostic codes and
correct problems which may arise.
Each time the engine is started the CHECK TRANS icon will light, then
turn off after a few seconds. This momentary lighting is to indicate that the
status light circuit is working properly. If the CHECK TRANS light does not
illuminate during start up, or if the light remains on after start up, the transmission
system should be checked immediately.
Continued illumination of the CHECK TRANS light during vehicle
operation (other than start up) indicates that the ECU has signaled a diagnostic
code. Illumination of the CHECK TRANS light is accompanied by a flashing
display from the shift selector. The shift selector display will show actual
range attained and the transmission will not respond to shift selector requests.
Indications from the shift selector are provided to inform the operator that
the transmission is not performing as designed and is operating at reduced
capabilities. Before turning the ignition off, the transmission may be operated
for a short time in the selected range in order to "limp home" for service
assistance. Service should be performed immediately in order to minimize
potential damage to the transmission.
When the Check Trans icon illuminates the keypad will not respond to
command and the transmission generally will downshift to 4th gear. The
torque converter will not "lock-up" and engine speed is automatically reduced.
Direction changes (i.e. forward to reverse) will not be allowed. Locate a safe
secure place to park the motorhome. If the engine is shut off, then engaged
after a Check Trans indication, the transmission remains in Neutral until the
fault causing the Check Trans light has been corrected.
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N A V I G A T O R 2 0 0 3
Chassis Information
Transmission
- Check Light
1 0 • 4 3 3