P0722

Diagnostic Chart:

Wiring Diagram:

CIRCUIT DESCRIPTION
The speed sensor circuit consists of a magnetic induction type sensor, which is the Output Shaft Speed (OSS) Sensor, a Vehicle Speed Sensor (VSS) Buffer Module, and wiring. Gear teeth pressed onto the output shaft carrier assembly induce an alternating voltage into the sensor. This signal transmits to the VSS Buffer Module. The VSS Buffer Module compensates for various final drive ratios. The VSS Buffer Module also converts the AC OSS Sensor signal into a 40 pulse per revolution (PPR) DC 5 volt square wave form signal on circuit 437 to indicate transmission output speed.
When the Powertrain Control Module (PCM) detects a low output speed when the vehicle has a high engine speed in a drive gear range, then DTC P0722 sets. DTC P0722 is a type B DTC.

CONDITIONS FOR SETTING THE DTC
^ No TFP Val. Position Sw. DTC P1810.
^ The APP Angle is greater than 12%.
^ The engine torque must be 100-565 Nm (80-450 lb. ft).
^ The engine speed must be 2000-3800 RPM.
^ The Automatic Transmission Input Speed Shaft (A/T ISS) Sensor speed is greater than 2000 RPM.
^ The transmission is not in Park or Neutral.
^ The engine vacuum is 0-105 kPa.
^ The OSS Sensor speed is less than 200 RPM for at least 3 seconds.

ACTION TAKEN WHEN THE DTC SETS
^ The PCM defaults to maximum line pressure.
^ The PCM freezes shift adapts.
^ The PCM defaults to the calculated output speed value using the Input Shaft Speed Sensor values.

CONDITIONS FOR CLEARING THE DTC
1. The PCM turns OFF the Malfunction Indicator Lamp (MIL) after three consecutive ignition cycles without a failure reported.
2. A scan tool can clear the DTC from the PCM history. The PCM clears the DTC from the PCM history if the vehicle completes 40 warm-up cycles without a failure reported.
3. The PCM cancels the DTC default actions when the fault no longer exists and the ignition is OFF long enough in order to power down the PCM.

DIAGNOSTIC AIDS
^ Inspect the wiring for poor electrical connections at the PCM. Inspect the wiring for poor electrical connections at the transmission 20-way connector. Look for the following problems:
- A bent terminal.
- A backed out terminal.
- A damaged terminal.
- Poor terminal tension.
- A chafed wire.
- A broken wire inside the insulation.
^ When diagnosing for an intermittent short or open, massage the wiring harness while watching the test equipment for a change. It may be necessary to drive the vehicle.
^ Inspect the Speed Sensor wiring for contact with sharp metal edges.

TEST DESCRIPTION
The numbers below refer to the step numbers on the diagnostic table.
2. This step verifies the fault condition.
3. This step tests OSS Sensor integrity.
9. This step verifies power and ground to the VSS Buffer Module.
15. This step verifies the PCM input controlled by the Speed Buffer.