A/T - AW4 Throttle Position Sensor (TP)
DATE: 1996TECHNICAL BULLETIN # 324A
TRANSMISSION: AW4
SUBJECT: [1][2]Throttle Position Sensor
APPLICATION: 1987-95 Jeep Cherokee
AW4 (Jeep)
[1][2]Throttle Position Sensor (TP)
The 1987-90 sensor has two pigtail leads. One has an in-line three pin connector, containing three wires. The other has a square four pin connector with three wires. The square connector is the one that is used for the transmission controller. These wires can be identified by the letters which are stamped into the connector.
Adjustment is simple, although backward by most TP standards. With the harness connected, test the voltage on pins A, B, & D. The voltage on pin "A" (reference voltage) should be approximately 5v.
NOTE:
TP malfunctions are rarely caused by low voltage on pin "A".
Voltage on pin "D" (ground) should be less than 0.1v. If the voltage is higher, an additional ground wire can be spliced into the circuit.
Pin "B" is the TP signal to the controller. The voltage on pin "B" should be 4.0-4.4v at closed throttle. At full throttle, the voltage should be 0.2-0.5v. The TP sensor has elongated holes for the hold-down screws which allow it to be adjusted.
The most common failure on this sensor is a spike of voltage at approximately 1/4-1/3 throttle. If this condition exists, the TP must be replaced. The most common complaints for this sensor are in and out of lock-up and erratic shift timing.
In 1991 Chrysler changed the TP design to one that was more conventional. Now, instead of having two harness connectors (one for the engine controller, the other for the transmission controller), they share the sensor signal from a common wire. Testing this sensor is similar to the earlier design (1987-90), however, the sensor signal is low at an idle and increases as the throttle is opened. Full-throttle voltage is approximately 4.5v. Signal voltage should change smoothly as the throttle is moved. If the signal moves erratically or is not within specifications, the sensor must be replaced, it is not adjustable.
Year Cylinder Part Numbers
1987-1990 2.54 cyl. 33000169
1987-1990 4.O6 cyl. 33004650
1991-1993 2.54 cyl. 4626051
1991-1993 4.06 cyl. 4626051
1994-1995 2.54 cyl. 4761871
1994-1995 4.06 cyl. 4761871