Aston Martin diagnostic trouble code
P2800: Shift-by-wire transmission range sensor circuit fault
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
- Transmission
- Manual coverage
- DB9
- Warning-lamp status
- DB9: MIL
What Aston Martin code P2800 means
Shift-by-wire transmission range sensor circuit fault
DB9 preliminary diagnostic manual · section 2-318
Manufacturer fault-analysis procedure
Test sequence and decision path
1. Connect the WDS and confirm that P2800 or
P2801 is logged.
2. With the ignition on, press and release the ‘P, R,
N and D’ buttons in turn.
If the lamp in each button illuminates, the circuit
to the Auto Switch Interface Unit, the PCM and
the TCM is serviceable. Go to step 3.
If any one lamp does not illuminate when its button is pressed and released, perform continuity
checks on the wiring between the switch and
interface box. Also check continuity of the wiring
to the telltale lamp in the suspect switch. Service
the switch or circuits as necessary. Clear the fault
code and run a brief road test to ensure that the
problem is resolved.
3. Using the WDS datalogger, monitor the PRND1
and PRND2 signals.
Key on. Press and release each switch in turn and
look for a corresponding change in the PRND signals.
If the PRND signal voltages are correct, the problem is not present at this time and testing is complete.
If the PRND signal voltages are not correct, if
either voltage does not change when any button
is pressed, check BVREF and SIG RTN at the
interface box. Service the BVREF and SIGRTN circuits as necessary. Repeat the voltage checks to
ensure that the problem is resolved.
If no fault is found with the BVREF and SIGRTN
lines, then check the continuity of the PRND1
and PRND2 signal lines. Service the wiring as
necessary. Clear the fault code and run a KOER
test including changes of gear to all modes to
ensure that the problem is resolved.
4. If PRND 1 or PRND 2 change when any single
button is pressed, but the voltages do not match
the PRND table, substitute each button in turn
with a new button and retest to ensure that the
PRND voltages are now correct.
IF the voltages are still not correct, check for
continuity/short circuit to power or ground from
each button to the interface box. Service any
identified faults and retest to ensure that the
problem is resolved.
Button
Pressed
PRND 1-
GND
PRND 2-
GND
PARK 0.45 2.26
NEUTRAL 1.08 2.26
DRIVE 1.74 2.26
REVERSE 2.16 2.26
NONE 2.62 3.71
Open the corresponding manual page for wiring diagrams and figures
P2801 is logged.
2. With the ignition on, press and release the ‘P, R,
N and D’ buttons in turn.
If the lamp in each button illuminates, the circuit
to the Auto Switch Interface Unit, the PCM and
the TCM is serviceable. Go to step 3.
If any one lamp does not illuminate when its button is pressed and released, perform continuity
checks on the wiring between the switch and
interface box. Also check continuity of the wiring
to the telltale lamp in the suspect switch. Service
the switch or circuits as necessary. Clear the fault
code and run a brief road test to ensure that the
problem is resolved.
3. Using the WDS datalogger, monitor the PRND1
and PRND2 signals.
Key on. Press and release each switch in turn and
look for a corresponding change in the PRND signals.
If the PRND signal voltages are correct, the problem is not present at this time and testing is complete.
If the PRND signal voltages are not correct, if
either voltage does not change when any button
is pressed, check BVREF and SIG RTN at the
interface box. Service the BVREF and SIGRTN circuits as necessary. Repeat the voltage checks to
ensure that the problem is resolved.
If no fault is found with the BVREF and SIGRTN
lines, then check the continuity of the PRND1
and PRND2 signal lines. Service the wiring as
necessary. Clear the fault code and run a KOER
test including changes of gear to all modes to
ensure that the problem is resolved.
4. If PRND 1 or PRND 2 change when any single
button is pressed, but the voltages do not match
the PRND table, substitute each button in turn
with a new button and retest to ensure that the
PRND voltages are now correct.
IF the voltages are still not correct, check for
continuity/short circuit to power or ground from
each button to the interface box. Service any
identified faults and retest to ensure that the
problem is resolved.
Button
Pressed
PRND 1-
GND
PRND 2-
GND
PARK 0.45 2.26
NEUTRAL 1.08 2.26
DRIVE 1.74 2.26
REVERSE 2.16 2.26
NONE 2.62 3.71