Allison

Main code 21 indicates the throttle position sensor has been retracted or extended by its linkage into an error zone. Code 21 12 is set when the ECU receives TPS counts of 14 or less. Whenever a Code 21 XX condition is detected, the system
defaults to 100 percent throttle and part throttle shifts will be abrupt.

Possible causes:
Sensor
Wiring to the sensor or the ECM
PWM signal problem

Main code 21 indicates the throttle position sensor has been retracted or extended by its linkage into an error zone.
This may be due to a fault with the sensor, or a fault in the wiring to the sensor or to the ECU. This code may also
indicate a PWM signal problem. Code 21 12 is set when the ECU receives TPS counts of 14 or less. Code 21 23 is
set when the ECU senses TPS counts of 233?255. Whenever a Code 21 XX condition is detected, the system
defaults to 100 percent throttle and part throttle shifts will be abrupt.

Main code 13 indicates either a high or low input voltage. Low voltage is less than 8V.
In the event of a power loss, the transmission fails to the ranges indicated in the following, depending upon which latch valve releases ?rst

Possible causes:
1) Bad batteries
2)Faulty vehicle charging system
3) No battery-direct power and ground

None, DNA

Main code 13 indicates either a high or low input voltage. High voltage is over 35V.
In the event of a power loss, the transmission fails to the ranges indicated in the following, depending upon which latch valve releases ?rst

Possible causes:
1) Faulty vehicle alternator
2) Faulty vehicle voltage regulator

Code 14 12 indicates the ECU has detected a voltage signal in the low error zone.
OLS ground wire 135B is common to the TPS and the RMR devices. A power wire short-to-ground for any of these devices will cause ?sensor failed low? codes (21 12 and 64 12). An OLS signal open or short-to-ground results in a Code 14 12 only.

Possible causes:
1) Faulty wiring to the OLS
2) A faulty OLS
3) A faulty ECU

Code 14 23 is programmed out of all calibrations.

Main code 21 indicates the throttle position sensor has been retracted or extended by its linkage into an error zone. Code 21 23 is set when the ECU senses TPS counts of 233?255. Whenever a Code 21 XX condition is detected, the system defaults to 100 percent throttle and part throttle shifts will be abrupt.

Possible causes:
1. Sensor
2. Wiring to the sensor or the ECM
3. PWM signal problem

Main code 22 indicates a fault within a speed sensor, the wiring to a speed sensor, incorrect speed sensor gap, or damaged bumps or teeth which create the speed signal. This fault is determined by the reasonableness of a speed sensor signal when compared with the other two speed sensors and the commanded range. A speed sensor will not pass the reasonableness test if there is no signal at all from that sensor when a signal should be present.

Main code 22 indicates a fault within a speed sensor, the wiring to a speed sensor, incorrect speed sensor gap, or damaged bumps or teeth which create the speed signal. This fault is determined by the reasonableness of a speed sensor signal when compared with the other two speed sensors and the commanded range. A speed sensor will not pass the reasonableness test if there is no signal at all from that sensor when a signal should be present.