Aston Martin diagnostic trouble code
P0502: Output Shaft Speed Sensor Short To Ground/Open Circuit
Use this reference to understand the recorded condition, confirm the available V8 Vantage or DB9 manual coverage, and follow the documented diagnostic checks before replacing parts.
- Code family
- Powertrain
- Vehicle system
- Electrical and control modules
- Manual coverage
- DB9
- Warning-lamp status
- DB9: Non-MIL
What Aston Martin code P0502 means
Output Shaft Speed Sensor Short To Ground/Open Circuit
DB9 preliminary diagnostic manual · section 2-120
Manufacturer fault-analysis procedure
Cautions and notes
NOTE: Vehicle speed is sensed from the diff speed sensor on auto cars and from the gearbox output speed
sensor on manual cars.
sensor on manual cars.
Test sequence and decision path
1. Connect the WDS and confirm that P0500,
P0501, P0502 or P0503 is logged. Clear the
logged fault code.
2. Set datalogger to monitor the VSS (output shaft
speed sensor) signal. run a brief road test (or rolling road test) with varying speeds.
Check if the recorded vehicle speed matches the
actual speed.
If the recorded speed does not match actual
speed, go to step 3 for manual cars or step 4 for
automatic cars.
If the VSS readings are accurate and no relevant
fault codes are logged, treat this as an intermittent
problem and service the VSS circuit for poor connections and shorts to power or ground
Run an extended road test to ensure that the
problem is resolved.
3. For Manual Cars:
Perform continuity checks between the following
connections:
VSS+ C1561-2 to primary PCM C0635-32 and
secondary PCM C0638-32.
VSS- C1561-1 to primary PCM C0635-33 and
secondary PCM C0638-33.
If any circuit fault is detected, service the circuit
as necessary. Clear the fault code and run a brief
road or rolling road test to ensure that the problem is resolved.
4. For Auto Cars:
Perform continuity checks between the following
connections:
VSS+ C0195-2 to primary PCM C0635-32 and
secondary PCM C0638-32.
VSS- C0195-1 to primary PCM C0635-33 and
secondary PCM C0638-33.
5. If no continuity fault is detected, go to step 6.
If any continuity fault is detected, service the circuit as necessary. Clear the fault code and run a
brief road or rolling road test to ensure that the
problem is resolved.
6. Check for short circuits to supply or ground by
performing voltage and continuity checks from
VSS+ and VSSto ground at the sensor.
If any short circuit fault is detected, service the
circuit as necessary. Clear the fault code and run
a brief road or rolling road test to ensure that the
problem is resolved.
Open the corresponding manual page for wiring diagrams and figures
P0501, P0502 or P0503 is logged. Clear the
logged fault code.
2. Set datalogger to monitor the VSS (output shaft
speed sensor) signal. run a brief road test (or rolling road test) with varying speeds.
Check if the recorded vehicle speed matches the
actual speed.
If the recorded speed does not match actual
speed, go to step 3 for manual cars or step 4 for
automatic cars.
If the VSS readings are accurate and no relevant
fault codes are logged, treat this as an intermittent
problem and service the VSS circuit for poor connections and shorts to power or ground
Run an extended road test to ensure that the
problem is resolved.
3. For Manual Cars:
Perform continuity checks between the following
connections:
VSS+ C1561-2 to primary PCM C0635-32 and
secondary PCM C0638-32.
VSS- C1561-1 to primary PCM C0635-33 and
secondary PCM C0638-33.
If any circuit fault is detected, service the circuit
as necessary. Clear the fault code and run a brief
road or rolling road test to ensure that the problem is resolved.
4. For Auto Cars:
Perform continuity checks between the following
connections:
VSS+ C0195-2 to primary PCM C0635-32 and
secondary PCM C0638-32.
VSS- C0195-1 to primary PCM C0635-33 and
secondary PCM C0638-33.
5. If no continuity fault is detected, go to step 6.
If any continuity fault is detected, service the circuit as necessary. Clear the fault code and run a
brief road or rolling road test to ensure that the
problem is resolved.
6. Check for short circuits to supply or ground by
performing voltage and continuity checks from
VSS+ and VSSto ground at the sensor.
If any short circuit fault is detected, service the
circuit as necessary. Clear the fault code and run
a brief road or rolling road test to ensure that the
problem is resolved.