Aston Martin diagnostic trouble code

P0068: MAF v Throttle Correlation Check

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
DB9
Warning-lamp status
DB9: MIL

What Aston Martin code P0068 means

MAF v Throttle Correlation Check

DB9 preliminary diagnostic manual · section 2-6

Manufacturer fault-analysis procedure

Manual fault definition

P0068 - MAF v Throttle Correlation Check

Cautions and notes

CAUTION: This codes may be generated in the
Primary or Secondary Powertrain Control Module
(PCM). Check that you are working on the correct
half of the engine.

NOTE: This code is monitored by comparing the LOAD
(Throttle plate position) and TP (Throttle Potentiometer)
parameters in the PCM. Any illogical set of comparison
data (i.e. throttle closed but load high) will trigger a
fault condition. The code will be logged under the following conditions:
If LOAD is greater than 60% and TP is less than 2.4
volts
or
If LOAD is less than 30% and TP is greater than 2.4
volts

NOTE: LOAD is calculated using the MAF sensor signal
as a primary control parameter.

If either the TP or LOAD signals show a discrepancy when compared bank to bank, consider the
readings from the PCM logging the P0068 code
as being suspect. Go to step 4.

Test sequence and decision path

1. Connect the WDS and confirm that a P0068 code
is logged. Note which PCM is indicating the fault
and record all other logged DTCs.

2. If any throttle potentiometer faults are logged,
resolve these codes first and return to this procedure only if P0068 is logged again after clearing
other throttle potentiometer codes.

3. Using WDS datalogger, record the TP, MAF and
LOAD parameters for both engine banks during a
KOER test. Open and close the throttle several
times to simulate an increasing/decreasing engine
load.

4. Disconnect the air trunking from both throttle
bodies. Switch on the ignition. Have a colleague
press and release the throttle pedal several times,
whilst monitoring the TP signal.
If the TP readings do not accurately follow the
throttle movement, Replace the throttle assembly.
If TP readings do accurately follow the throttle
movement, the MAF sensor is suspect. Go to step

5.

5. Note the MAF readings from step 3. Swap the
MAF sensors bank to bank. Clear the P0068 code
and run a fresh KOER test.
If the fault is logged on the other engine bank and
the MAF trsace is suspect, replace the faulty MAF
sensor, clear the P0068 code and run a further
KOER test to ensure that the problem is resolved.
If the fault is logged again on the original engine
bank, service the MAF sensor wiring as necessary,
clear the P0068 code and run a further KOER test
to ensure that the problem is resolved.
NY,0.5
NY,0.5
NY,0.5
B,0.5
NY,0.5
NY,0.5
B,0.5
SW,0.5
UR,0.5
UG,0.5
UR,0.5
UG,0.5
SW,0.5
BP,0.5 BP,0.5
UG,0.5
UR,0.5
UY,0.5
UR,0.5
UG,0.5
UY,0.5
UB,0.5 BP,0.5
Sensor-Mass Air Flow (1-6)
Sensor-Mass Air Flow (7-12)
Underbonnet Fusebox
RELAY 3
Sheet 61C2409-1
DIODE 4
Module
Central Electronic
F54
10.0 Amps
C2275-10
Sensor A
Earth-MAF
Sheet 61
RELAY 5
DIODE 5
F13
20.0 Amps
F9
20.0 Amps
C2275-5
Sensor B
Earth-MAF
C2275-9
C2275-8
C2275-7
C2275-6
Primary PCM
C2275-4
C2275-3
C2275-2
C2275-1
Secondary PCM
C0149-5G
GND
C0149-6G
VPWR
C2370-6G
VPWR
C2370-5G
GND
C0579-8 VIGN
C0584-39
IGN. OUT
C0574-6 GND
C0551-1
SPL2-VIGN/EN
C2608-1 VBATT
C0578-2
C0577-6 C0552-1
SPL5-VIGN/EN
C0149-1G
IAT
C0149-2G
SIGRTN
C0149-4G
MAFRTN
C0149-3G
MAF
SPL13-SRTN/EN
C0636-41G
SIGRTNA
C0636-13G
IAT
C0634-9G
MAF+
C0634-10G
MAF-
C2370-2G
SIGRTN
C2370-4G
MAFRTN
C2370-3G
MAF
C2370-1G
IAT
SPL6-SRTN/EN
C0637-10G
MAF-
C0637-9G
MAF+
C2464-41G
SIGRTNA
C2464-13G
IAT
Open the corresponding manual page for wiring diagrams and figures