Aston Martin diagnostic trouble code
P0102: Mass or Volume Air Flow Circuit Low Input
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
- Fuel and air
- Manual coverage
- V8 Vantage, DB9
- Warning-lamp status
- V8 Vantage: MIL; DB9: MIL
What Aston Martin code P0102 means
Mass or Volume Air Flow Circuit Low Input
DB9 preliminary diagnostic manual · section 2-10
Manufacturer fault-analysis procedure
Manual fault definition
P0102 - The MAF signal went below 0.24 volts
during normal engine running.
during normal engine running.
Cautions and notes
CAUTION: This code may be generated in the
Primary or Secondary PCM. Check that you are
working on the correct half of the engine.
Primary or Secondary PCM. Check that you are
working on the correct half of the engine.
Test sequence and decision path
1. Connect the WDS or Scan Tool. Check that fault
code P0102 is present. Set the datalogger to monitor both MAF signals.
2. Check the air filter and all ducting for blockage or
leaks. Repair if necessary.
3. Run the engine up to 1500 rpm for 5 seconds.
Read both Mass Air Flow signals and check if
either MAF voltage is less than 0.24V (i.e. below
minimum volts).
If both MAF signals are in range, the fault is not
present at this time and testing is complete.
If either MAF voltage is below 0.24 volts, go to
step 4.
4. Check the VPWR voltage on MAF sensor pin 6. If
the supply voltage is below 10.5 volts, key off.
Remove underbonnet fuses F18 (MAF 1-6) or F6
(MAF 7-12). Check the fuse continuity and
replace if necessary.
Switch on the ignition. Check for correct 12V
ignition supply at the fuse input terminal.
If the voltage is below 10.5V, troubleshoot the
Battery + supply through underbonnet relays 5
and 3.
If the voltage is in the range 10.5-13.5V, troubleshoot and repair the open circuit in the 12V supply from F18 or F6 to MAF sensor connector pin
C2370-6 or C0149-6. Replace F18 and F6.
Switch on the ignition and clear the P0102 code.
Repeat the KOER test to ensure that the P0102
problem is resolved.
5. Key off, disconnect the MAF Sensor, key on
engine off. Measure the voltage across MAF harness connector pin 6 +12V EMS supply and pin 5
Power Ground. The supply voltage must be
greater than 10.5 Volts and less than 13.5 volts.
If the voltage is in range, go to step 6, if not, go to
step 5.
6. Key off, disconnect the PCM connector and
install the break-out box. Check continuity from
the following MAF harness connector pins to the
PCM connector pins listed.
MAF pin 5 to chassis ground
MAF pin 3 to primary PCM pin C0634-9 (MAF+)
or MAF pin 3 to secondary PCM pin C0637-9
(MAF+)
MAF pin 4 to primary PCM pin C0634-10 (MAF-)
or MAF pin 4 to secondary PCM pin C0637-10
(MAF-)
If any open circuit is identified, repair the fault.
Reconnect the MAF sensor and the PCM. Switch
on the ignition and clear the P0102 code. Repeat
the KOER test to ensure that the P0102 problem is
resolved.
If no open circuit is detected, go to step 7.
7. Reconnect the MAF sensor. Key on and start the
engine.
Check the MAF signal level between pins 3 and 4
of the sensor connector.
If the signal is below 0.27 volts, replace the MAF
sensor.
If the signal level is above 0.27 volts and code
P0102 persists, call Aston Martin technical support.
Open the corresponding manual page for wiring diagrams and figures
code P0102 is present. Set the datalogger to monitor both MAF signals.
2. Check the air filter and all ducting for blockage or
leaks. Repair if necessary.
3. Run the engine up to 1500 rpm for 5 seconds.
Read both Mass Air Flow signals and check if
either MAF voltage is less than 0.24V (i.e. below
minimum volts).
If both MAF signals are in range, the fault is not
present at this time and testing is complete.
If either MAF voltage is below 0.24 volts, go to
step 4.
4. Check the VPWR voltage on MAF sensor pin 6. If
the supply voltage is below 10.5 volts, key off.
Remove underbonnet fuses F18 (MAF 1-6) or F6
(MAF 7-12). Check the fuse continuity and
replace if necessary.
Switch on the ignition. Check for correct 12V
ignition supply at the fuse input terminal.
If the voltage is below 10.5V, troubleshoot the
Battery + supply through underbonnet relays 5
and 3.
If the voltage is in the range 10.5-13.5V, troubleshoot and repair the open circuit in the 12V supply from F18 or F6 to MAF sensor connector pin
C2370-6 or C0149-6. Replace F18 and F6.
Switch on the ignition and clear the P0102 code.
Repeat the KOER test to ensure that the P0102
problem is resolved.
5. Key off, disconnect the MAF Sensor, key on
engine off. Measure the voltage across MAF harness connector pin 6 +12V EMS supply and pin 5
Power Ground. The supply voltage must be
greater than 10.5 Volts and less than 13.5 volts.
If the voltage is in range, go to step 6, if not, go to
step 5.
6. Key off, disconnect the PCM connector and
install the break-out box. Check continuity from
the following MAF harness connector pins to the
PCM connector pins listed.
MAF pin 5 to chassis ground
MAF pin 3 to primary PCM pin C0634-9 (MAF+)
or MAF pin 3 to secondary PCM pin C0637-9
(MAF+)
MAF pin 4 to primary PCM pin C0634-10 (MAF-)
or MAF pin 4 to secondary PCM pin C0637-10
(MAF-)
If any open circuit is identified, repair the fault.
Reconnect the MAF sensor and the PCM. Switch
on the ignition and clear the P0102 code. Repeat
the KOER test to ensure that the P0102 problem is
resolved.
If no open circuit is detected, go to step 7.
7. Reconnect the MAF sensor. Key on and start the
engine.
Check the MAF signal level between pins 3 and 4
of the sensor connector.
If the signal is below 0.27 volts, replace the MAF
sensor.
If the signal level is above 0.27 volts and code
P0102 persists, call Aston Martin technical support.