DTC P0112 [YF (2.0L Zetec)]

id0102d0803700

DTC P0112

IAT circuit low input

DETECTION CONDITION

• PCM monitors input voltage from IAT sensor when engine is running. If input voltage at PCM terminal 39 is below 0.2 V, PCM determines that IAT circuit has a malfunction.

POSSIBLE CAUSE

• IAT sensor malfunction
• Connector or terminal malfunction
• Open circuit in wiring between MAF/IAT sensor terminal 6 and PCM terminal 39
• Short to ground in wiring between MAF/IAT sensor terminal 6 and PCM terminal 39
• Open circuit in wiring between MAF/IAT sensor terminal 1 and PCM terminal 91
• PCM malfunction

Diagnostic procedure

STEP

INSPECTION

ACTION

1
VERIFY FREEZE FRAME DATA HAS BEEN RECORDED
• Has FREEZE FRAME DATA been recorded?
Yes
Go to next step.
No
Record FREEZE FRAME DATA on repair order, then go to next step.
2
VERIFY RELATED SERVICE INFORMATION AVAILABILITY
• Check for related Service Information availability.
• Is any related Service Information available?
Yes
Perform repair or diagnosis according to available Service Information.
• If vehicle is not repaired, go to next step.
No
Go to next step.
3
INSPECT MAF/IAT SENSOR CONNECTOR FOR POOR CONNECTION
• Turn ignition key to OFF.
• Disconnect the MAF/IAT sensor connector.
• Check for poor connection (damaged, pulled-out terminals, corrosion, etc.).
• Is there any malfunction?
Yes
Repair or replace terminals, then go to Step 7.
No
Go to next step.
4
INSPECT PCM CONNECTOR FOR POOR CONNECTION
• Turn ignition key to OFF.
• Disconnect PCM connector.
• Check for poor connection (damaged, pulled-out terminals, corrosion, etc.).
• Is there any malfunction?
Yes
Repair terminal, then go to Step 7.
No
Go to next step.
5
INSPECT IAT SENSOR SIGNAL CIRCUIT FOR OPEN CIRCUIT
• Disconnect PCM connector.
• Inspect for continuity between MAF/IAT sensor terminal 1 (harness-side) and PCM terminal 91 (harness-side).
• Is there any continuity?
Yes
Go to next step.
No
Repair or replace suspected harness, then go to Step 7.
6
INSPECT IAT SENSOR SIGNAL CIRCUIT FOR SHORT TO GND
• Inspect for continuity between MAF/IAT sensor terminal 6 (harness-side) and body ground
• Is there any continuity?
Yes
Repair or replace suspected harness, then go to next step.
No
Replace MAF/IAT sensor, then go to next step.
7
VERIFY TROUBLESHOOTING OF DTC P0112 COMPLETED
• Make sure to reconnect all disconnected connectors.
• Clear DTC from memory using WDS or equivalent.
• Start engine.
• Perform "KOEO/KOER self-test"
• Is same DTC present?
Yes
Replace PCM, then go to next step.
No
Go to next step.
8
VERIFY AFTER REPAIR PROCEDURE
• Perform "After Repair Procedure".
• Is there any DTC present?
Yes
Go to applicable DTC inspection.
No
Troubleshooting completed.