Aston Martin diagnostic trouble code
P0112: Intake Air Temperature Sensor 1 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
- Cooling and temperature
- Manual coverage
- V8 Vantage, DB9
- Warning-lamp status
- V8 Vantage: MIL; DB9: MIL
What Aston Martin code P0112 means
Intake Air Temperature Sensor 1 Circuit Low Input
DB9 preliminary diagnostic manual · section 2-22
Manufacturer fault-analysis procedure
Manual fault definition
P0112 - The IAT signal went below 0.2 volts during continuous testing. (Temperature reading excessively high)
P0113 - The IAT signal went above 4.60 volts during continuous testing. (Temperature reading excessively low)
P0114 - The IAT signal was intermittent or erratic
P0113 - The IAT signal went above 4.60 volts during continuous testing. (Temperature reading excessively low)
P0114 - The IAT signal was intermittent or erratic
Cautions and notes
CAUTION: These 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.
Primary or Secondary Powertrain Control Module
(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 and confirm that
P0112, P0113 or P0114 is present.
2. Run the engine and read the Intake Air Temperature signal. The voltage should be in the range
0.27 - 3.51 volts (see the table of IAT Sensor Values).
3. P0112 - For low voltage readings, suspect a short
circuit of the signal (Primary PCM pin C0636-13
or secondary PCM pin C2464-13) to ground or to
signal return.
Key off, connect the PCM break-out box and
check for short circuit between the lines from following PCM pins:
Primary PCM pin C0636-13 to the MAF/IAT sensor and from the MAF/IAT sensor to PCM pin
C0636-41 (i.e. between the IAT signal and IAT
signal return lines).
or
Secondary PCM pin C2464-13 to the MAF/IAT
sensor and from the MAF/IAT sensor to PCM pin
C2464-41 (i.e. between the IAT signal and IAT
signal return lines).
Also check for short circuit to ground on the line
from Primary PCM pin C0636-13 or Secondary
PCM pin C2464-13 to the chassis ground.
If a short circuit is identified, service the wiring as
necessary. Reconnect the components and go to
step 6.
4. P0113 - For high voltage readings (above 4.60
volts) suspect an open circuit in the sensor wiring
or internally within the sensor.
Key off, disconnect the MAF/IAT sensor, key on.
Measure the voltage across the MAF/IAT sensor
harness connector pin 6 and pin 5, key on.
Approximately 12.0 volts should be present.
If 12V is not present, there is an open circuit in
the 12V supply line or in the PWRGND line.
Service the wiring as necessary and go to step 5.
If approximately 12.0 volts is present, check the
resistance of the IAT sensor. Consult the table
below, the resistance should be within 15% of the
values in the table. If the resistance is very high or
infinite, change the IAT sensor.
Go to step 6
5. P0114 - For intermittent/erratic signal levels,
monitor the Intake Air Temperature signal whilst
shaking/wiggling the engine harness between the
affected MAF sensor and the PCM.
If any inconsistency is identified, service the
affected part of the harness as necessary. Clear
the P0114 code and run a KOER test to ensure
that the problem is resolved.
6. Clear the P0112/P0113/P0114 code, run the
drive cycle to ensure that the problem is resolved.
Table of IAT Sensor Values
Temperature Voltage Resistance
°F °C Volts K Ohms
248 120 0.27 1.18
230 110 0.35 1.55
212 100 0.46 2.07
194 90 0.60 2.80
176 80 0.78 3.84
158 70 1.02 5.37
140 60 1.33 7.70
122 50 1.70 10.97
104 40 2.13 16.15
86 30 2.60 24.27
68 20 3.07 37.30
50 10 3.51 58.75
Open the corresponding manual page for wiring diagrams and figures
P0112, P0113 or P0114 is present.
2. Run the engine and read the Intake Air Temperature signal. The voltage should be in the range
0.27 - 3.51 volts (see the table of IAT Sensor Values).
3. P0112 - For low voltage readings, suspect a short
circuit of the signal (Primary PCM pin C0636-13
or secondary PCM pin C2464-13) to ground or to
signal return.
Key off, connect the PCM break-out box and
check for short circuit between the lines from following PCM pins:
Primary PCM pin C0636-13 to the MAF/IAT sensor and from the MAF/IAT sensor to PCM pin
C0636-41 (i.e. between the IAT signal and IAT
signal return lines).
or
Secondary PCM pin C2464-13 to the MAF/IAT
sensor and from the MAF/IAT sensor to PCM pin
C2464-41 (i.e. between the IAT signal and IAT
signal return lines).
Also check for short circuit to ground on the line
from Primary PCM pin C0636-13 or Secondary
PCM pin C2464-13 to the chassis ground.
If a short circuit is identified, service the wiring as
necessary. Reconnect the components and go to
step 6.
4. P0113 - For high voltage readings (above 4.60
volts) suspect an open circuit in the sensor wiring
or internally within the sensor.
Key off, disconnect the MAF/IAT sensor, key on.
Measure the voltage across the MAF/IAT sensor
harness connector pin 6 and pin 5, key on.
Approximately 12.0 volts should be present.
If 12V is not present, there is an open circuit in
the 12V supply line or in the PWRGND line.
Service the wiring as necessary and go to step 5.
If approximately 12.0 volts is present, check the
resistance of the IAT sensor. Consult the table
below, the resistance should be within 15% of the
values in the table. If the resistance is very high or
infinite, change the IAT sensor.
Go to step 6
5. P0114 - For intermittent/erratic signal levels,
monitor the Intake Air Temperature signal whilst
shaking/wiggling the engine harness between the
affected MAF sensor and the PCM.
If any inconsistency is identified, service the
affected part of the harness as necessary. Clear
the P0114 code and run a KOER test to ensure
that the problem is resolved.
6. Clear the P0112/P0113/P0114 code, run the
drive cycle to ensure that the problem is resolved.
Table of IAT Sensor Values
Temperature Voltage Resistance
°F °C Volts K Ohms
248 120 0.27 1.18
230 110 0.35 1.55
212 100 0.46 2.07
194 90 0.60 2.80
176 80 0.78 3.84
158 70 1.02 5.37
140 60 1.33 7.70
122 50 1.70 10.97
104 40 2.13 16.15
86 30 2.60 24.27
68 20 3.07 37.30
50 10 3.51 58.75