DTC Troubleshooting: P0112
DTC P0112: IAT Sensor 1 Circuit Low Voltage
NOTE: Before you troubleshoot, review the general troubleshooting information.

DTC Description
Confirmed DTC
Pending DTC
P0112 IAT Sensor 1 Circuit Low Voltage
   

1.
Problem verification:

Problem verification
?1.
Turn the vehicle to the ON mode.

?2.
Check the parameter(s) below with the HDS.
Signal
Threshold
Current conditions
Values
Unit
Values
Unit
IAT SENSOR (1)
Less than 0.08
V
    

Do the current condition(s) match the threshold?

     
YES
     
     
     
The failure is duplicated. Go to step 2.
     
NO
     
     
     
Intermittent failure, the system is OK at this time. Check for poor connections or loose terminals at MAF sensor/IAT sensor 1 and the PCM. If the on-board snapshot of this DTC is recorded, try to reproduce the failure under the same conditions with the on-board snapshot.?
2.
Determine possible failure area (MAF sensor/IAT sensor 1, others):

Determine possible failure area (MAF sensor/IAT sensor 1, others)
?1.
Turn the vehicle to the OFF (LOCK) mode.

?2.
Disconnect the following connector.
MAF sensor/IAT sensor 1 4P connector

?3.
Turn the vehicle to the ON mode.

?4.
Check the parameter(s) below with the HDS.
Signal
Threshold
Current conditions
Values
Unit
Values
Unit
IAT SENSOR (1)
Less than 0.08
V
    

Do the current condition(s) match the threshold?

     
YES
     
     
     
Go to step 3.
     
NO
     
     
     
3.
Shorted wire check (ITA1(TA) line):

Shorted wire check (ITA1(TA) line)
?1.
Turn the vehicle to the OFF (LOCK) mode.

?2.
Jump the SCS line with the HDS, and wait more than 1 minute.


?3.
Disconnect the following connector.
PCM connector E (80P)

?4.
Check for continuity between test points 1 and 2.
Test condition
Vehicle OFF (LOCK) mode
 
MAF sensor/IAT sensor 1 4P connector: disconnected
 
PCM connector E (80P): disconnected
Test point 1
MAF sensor/IAT sensor 1 4P connector (female terminals) No. 4:
Test point 2
Body ground


Is there continuity?

     
YES
     
     
     
Repair a short in the ITA1(TA) wire between the PCM (E53) and MAF sensor/IAT sensor 1.?
     
NO
     
     
     
The ITA1(TA) wire is OK. Check for any authorized service information related to the DTCs or symptoms you are troubleshooting, or substitute a known-good PCM, then recheck. If DTC P0112 goes away and the PCM was substituted, replace the original PCM.?