For 1990-2009 cars

## DTC P0503 L61

### Circuit Description

When the vehicle speed is above 5 km/h (3 mph), the output speed sensor (OSS) produces an AC voltage of different amplitude and frequency depending upon the rotation of the output shaft. The OSS produces the signal from 16 evenly spaced machined notches on the transaxle final drive assembly. The OSS signal is transmitted to the PCM, and is used to determine the rotation of the output shaft. When the PCM detects a dropout in the OSS signal for a certain length of time while the vehicle is moving, DTC P0503 sets.

### Conditions for Setting the DTC

DTC P0503 will set if the transmission OSS signal drops more than 1,200 RPM when:

• | The dropout condition exist for longer than 3 seconds.

• | The engine speed is greater than 500 RPM.

• | The transmission range is a drive range .

• | The transmission OSS does not increase by more than 250 RPM within a 100 ms time period for more than 0.5 seconds.

• | The time since the gear selector has been moved is greater than 6 seconds for MY 2002.

• | DTC P1810 has not been set for MY 2002.

• | Engine torque is between 68-237 N·m (50-175 lb ft) for MY 2003.

DTC P0503 diagnostic runs continuously when the above conditions have been met.

DTC P0503 is a type B DTC.

### Diagnostic Aids

If DTC P0502 is also set, diagnose that DTC first.

To locate this intermittent problem, use a scan tool to monitor TRANSMISSION OSS with the vehicle raised and the drive wheels moving greater than 5 km/h (3 mph). The parameter will drop out if a fault occurs.

DTC P0503 can set if a direct or intermittent short to voltage on circuit 400 occurs, an intermittent open occurs anywhere in the circuit, or an intermittent short to ground in circuit 400 occurs.

Inspect the TRANSMISSION OSS and differential carrier reluctor wheel teeth for damage. If the PCM does not receive a TRANSMISSION OSS signal or if DTC P0503 is active, it will command maximum main line pressure to the transaxle.

The output speed sensor resistance is 1,530-1,870 ohms.

## DTC P0503 L81

### Circuit Description

When the vehicle speed is above 5 km/h (3 mph), the output speed sensor (OSS) produces an AC voltage of different amplitude and frequency depending upon the rotation of the output shaft. The OSS produces the signal from 16 evenly spaced machined notches on the transaxle final drive assembly. The OSS signal is transmitted to the TCM, and is used to determine the rotation of the output shaft. When the TCM detects a dropout in the OSS signal for a certain length of time while the vehicle is moving, DTC P0503 sets.

### Conditions for Setting the DTC

DTC P0503 will set if the transmission OSS signal drops more than 600 RPM when:

• | The dropout condition exist for longer than 3 seconds.

• | The transmission OSS is greater than 300 RPM and does not increased by more than 250 RPM within a 100 ms time period for more than 2 seconds.

• | The transmission ISS does not increase more than 500 RPM within a 100 ms time period for more than 2 seconds.

• | The engine torque is between 100-150 N·m (74-111 lb ft).

• | The engine speed is between 200-7,500 RPM for 5 seconds for MY 2002, or 500-6,500 RPM for 5 seconds for MY 2003.

• | The transmission range is a drive range.

• | The TFP range is not Park/Neutral for MY 2002.

• | The time since the gear selector has been moved is greater than 6 seconds for MY 2002.

• | DTC P0716 and P0717 have not set.

• | DTC P1810 has not been set for MY 2002.

• | DTC P1842 has not set for MY 2003.

DTC P0503 diagnostic runs continuously when the above conditions have been met.

DTC P0503 is a type B DTC.

### Diagnostic Aids

If DTC P0502 is also set, diagnose that DTC first.

To locate this intermittent problem, use the scan tool to monitor the TRANSMISSION OSS with the vehicle raised and the drive wheels moving greater than 5 km/h (3 mph). The parameter will drop out if a fault occurs.

DTC P0503 can set if a direct or intermittent short to voltage on circuit 400 occurs, an intermittent open occurs anywhere in the circuit, or an intermittent short to ground in circuit 400 occurs.

Inspect the TRANSMISSION OSS and differential carrier reluctor wheel teeth for damage. If the PCM does not receive an OSS signal or if DTC P0503 is active, it will command maximum main line pressure to the transaxle.

If the TCM does not receive a TRANSMISSION OSS signal, it will calculate vehicle speed based on engine speed, input shaft speed, and commanded gear. The speedometer will still be inoperative, however.

The output speed sensor resistance is 1,530-1,870 ohms.