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Posted on Feb 16, 2011
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Hello my check engine light is on i went to local parts house had them read the code low input voltage in the iat sensor so i bought a new one had the code cleared and before i left parking lot light was back on went back same code can you give me some ideas as to what may be wrong thanks chad my truck is a 1998 chevy 3500 with the 5.7

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  • Chevrolet Master 17,989 Answers
  • Posted on Feb 16, 2011
ZJ Limited
Chevrolet Master
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Keep in mind that the IAT (intake air temperature) sensor simply measures the temperature of air that is entering the engine. Intake air temperature is important because the higher the intake air, the higher the combustion temperatures. High combustion temperatures result in increased Nox (Nitrogen oxides) emissions. To keep these higher temps from causing increased combustion temps, the intake air tubing should be intact, allowing the engine to "breathe" air that isn't sampled from the engine compartment. The IAT measures air temp by using a thermistor, or a thermometer of sorts. The thermistor is supplied 5 volts reference voltage from the PCM (powertrain control module) and a ground. Usually, when the air temperature is cold the resistance in the thermistor is high and when the air temperature is warmer, the resistance decreases. This change in resistance changes the 5 V reference from the PCM, thereby informing the PCM of the temperature of incoming air. If the PCM notices that the incoming air temp is unusually high, say, 300 degrees, when the engine temp is still relatively low, it will set a P0112.

Symptoms: There may be no noticeable symptoms of a P0112 code other than an MIL (Malfunction Indicator Lamp). However, a emissions test may reveal higher Nox readings depending on the type of IAT failure. Or the engine may ping under load, depending on the type of IAT failure.

Causes: Usually the P0112 is caused by a bad IAT (internally shorted or open or otherwise damaged), but it could also be:
* No reference voltage to the IAT sensor due to an open wire
* Excessively high intake air temperatures
* Short to ground on signal circuit
* Damaged IAT connector
* Bad PCM

Possible Solutions:
Hook up your scan tool or code reader and read the IAT reading. With a cold engine, the IAT should roughly match the coolant reading, since both will read ambient temperature. If the IAT is reading excessively high, check the IAT connector for damage. If you find none, unplug the IAT sensor and recheck the reading. It should now read the minimum, around -20 deg. If it does, then replace the IAT sensor. But, if the reading is still high, unplug the sensor and check for resistance across the two wiring harness terminals. If there is infinite resistance, then the PCM itself is bad. If the resistance isn't infinite, then check and repair the short to ground on the signal circuit.

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1answer

Code P0113-P0183

DTC P0113 - Intake Air Temperature Circuit High Input.The powertrain control module (PCM) monitors the temperature of the air entering the engine. The PCM supplies a 5 volt reference voltage to the Intake Air Temperature (IAT) sensor. The IAT is a thermistor that varies resistance based on temperature. As the temperature increases, resistance decreases. Low temperature results in a high signal voltage. When the PCM sees a signal voltage higher than 5 volts, it sets this P0113 check engine light code.


DTC P0183 - Fuel Temperature Sensor Circuit High Voltage.


I suggest to check wire connections.
2helpful
1answer

Won't start, has spark at plug, fuel pump sounds like it turns on, starter is working, obd11 code p0113

OBD II DTC P0113 - Intake Air Temperature Circuit High Input

This code means that the Powertrain Control Module (PCM) monitors the temperature of the air entering the engine. The PCM supplies a 5 volt reference voltage to the Intake Air Temperature (IAT) sensor. The IAT is a thermistor that varies resistance based on temperature. As the temperature increases, resistance decreases. Low temperature results in a high signal voltage. When the PCM sees a signal voltage higher than 5 volts, it sets this P0113 check engine light code.

There will likely be no symptoms other than illumination of the Malfunction Indicator Lamp (MIL - Check Engine Light / Service Engine Soon).

A code P0113 may mean that one or more of the following has happened:
Internally failed IAT sensor
Faulty connection at IAT sensor
Open in IAT ground circuit or signal circuit
Short to voltage in IAT signal circuit or reference circuit
IAT harness and/or wiring routed too close to high-voltage wiring (e.g. alternator, spark plug cables, etc.)
Faulty PCM (less likely but not impossible)

To solve it, first, if you have access to a scan tool, is there an IAT reading? If the IAT reading is logical then the problem is likely intermittent. If the reading is less than -30 degrees, unplug the connector. Install a jumper wire between the harness connector signal and ground circuits. The IAT temperature reading on the scan tool should be maxed out at the high end. For example it should be 280 degrees Farenheit or higher. If it is, the wiring is okay, and it may have been the connection. If it isn't install the jumper wire between the IAT signal circuit and the chassis ground.

If now the IAT reading on the scan tool is maxed out then check for an open in the IAT ground circuit. If you get no reading at all on the scan tool, it's likely that the sensor signal is open or the 5 volt reference is missing. Check using a DVOM (digital volt ohm meter) for a 5 volt reference. If it's there, then unplug the connector at the PCM and check for continuity on the IAT signal circuit between the PCM connector and the IAT connector.

Hope this helps; remember to rating this free answer and leave us a testimonial comments.
0helpful
1answer

Hello people i got a gmc 99 jimmy 2door sls the engine light keeps coming on then going out ive coded it to be an iat sensor and also says the iat sensor intermitten voltage high and then the knock sensor...

the IAT may be bad or the connector is bad, real common (friend should know to check that) get a real scanner and see what the IAT is reading, then move the connector and see if it changes. if it reads -40f then its bad or disconnected.
3helpful
1answer

P0113 code for the intake air temperature sensor

Thank you for the inquiry.
P0113
Intake Air Temperature Circuit High Input
P0114 Intake Air Temperature Circuit
P0113 - Intake Air Temperature Circuit High Input

The powertrain control module (PCM) monitors the temperature of the air entering the engine. The PCM supplies a 5 volt reference voltage to the Intake Air Temperature (IAT) sensor. The IAT is a thermistor that varies resistance based on temperature. As the temperature increases, resistance decreases. Low temperature results in a high signal voltage. When the PCM sees a signal voltage higher than 5 volts, it sets this P0113 check engine light code.

Potential Symptoms: There will likely be no symptoms other than illumination of the Malfunction Indicator Lamp (MIL - Check Engine Light / Service Engine Soon).
Causes: A code P0113 may mean that one or more of the following has happened:
* Internally failed IAT sensor
* Faulty connection at IAT sensor
* Open in IAT ground circuit or signal circuit
* Short to voltage in IAT signal circuit or reference circuit
* IAT harness and/or wiring routed too close to high-voltage wiring (e.g. alternator, spark plug cables, etc.)
* Faulty PCM (less likely but not impossible)

Possible Solutions:
1. First, if you have access to a scan tool, is there an IAT reading? If the IAT reading is logical then the problem is likely intermittent. If the reading is less than -30 degrees, unplug the connector. Install a jumper wire between the harness connector signal and ground circuits. The IAT temperature reading on the scan tool should be maxed out at the high end. For example it should be 280 degrees Farenheit or higher. If it is, the wiring is okay, and it may have been the connection. 2. If it isn't install the jumper wire between the IAT signal circuit and the chassis ground.
3. If now the IAT reading on the scan tool is maxed out then check for an open in the IAT ground circuit. If you get no reading at all on the scan tool, it's likely that the sensor signal is open or the 5 volt reference is missing. Check using a DVOM (digital volt ohm meter) for a 5 volt reference. If it's there, then unplug the connector at the PCM and check for continuity on the IAT signal circuit between the PCM connector and the IAT connector.


Hope helps; keep us updated and remember to rate this answer
1helpful
2answers

MOtor is racing code comes upPO113

P0113 - Intake Air Temperature Circuit High Input
The powertrain control module (PCM) monitors the temperature of the air entering the engine. The PCM supplies a 5 volt reference voltage to the Intake Air Temperature (IAT) sensor. The IAT is a thermistor that varies resistance based on temperature. As the temperature increases, resistance decreases. Low temperature results in a high signal voltage. When the PCM sees a signal voltage higher than 5 volts, it sets this P0113 check engine light code.

Potential Symptoms: There will likely be no symptoms other than illumination of the Malfunction Indicator Lamp (MIL - Check Engine Light / Service Engine Soon).

Causes: A code P0113 may mean that one or more of the following has happened:
Internally failed IAT sensor
Faulty connection at IAT sensor
Open in IAT ground circuit or signal circuit
Short to voltage in IAT signal circuit or reference circuit
IAT harness and/or wiring routed too close to high-voltage wiring (e.g. alternator, spark plug cables, etc.)
Faulty PCM (less likely but not impossible)

Possible Solutions:
First, if you have access to a scan tool, is there an IAT reading? If the IAT reading is logical then the problem is likely intermittent. If the reading is less than -30 degrees, unplug the connector. Install a jumper wire between the harness connector signal and ground circuits. The IAT temperature reading on the scan tool should be maxed out at the high end. For example it should be 280 degrees Farenheit or higher. If it is, the wiring is okay, and it may have been the connection. If it isn't install the jumper wire between the IAT signal circuit and the chassis ground.

If now the IAT reading on the scan tool is maxed out then check for an open in the IAT ground circuit. If you get no reading at all on the scan tool, it's likely that the sensor signal is open or the 5 volt reference is missing. Check using a DVOM (digital volt ohm meter) for a 5 volt reference. If it's there, then unplug the connector at the PCM and check for continuity on the IAT signal circuit between the PCM connector and the IAT connector.

Hope this helps (remember to rate this answer).
3helpful
1answer

Code po113

P0113 - Intake Air Temperature Circuit High Input

The powertrain control module (PCM) monitors the temperature of the air entering the engine. The PCM supplies a 5 volt reference voltage to the Intake Air Temperature (IAT) sensor. The IAT is a thermistor that varies resistance based on temperature. As the temperature increases, resistance decreases. Low temperature results in a high signal voltage. When the PCM sees a signal voltage higher than 5 volts, it sets this P0113 check engine light code.

Potential Symptoms: There will likely be no symptoms other than illumination of the Malfunction Indicator Lamp (MIL - Check Engine Light / Service Engine Soon).
Causes: A code P0113 may mean that one or more of the following has happened:
* Internally failed IAT sensor
* Faulty connection at IAT sensor
* Open in IAT ground circuit or signal circuit
* Short to voltage in IAT signal circuit or reference circuit
* IAT harness and/or wiring routed too close to high-voltage wiring (e.g. alternator, spark plug cables, etc.)
* Faulty PCM (less likely but not impossible)

Possible Solutions:
1. First, if you have access to a scan tool, is there an IAT reading? If the IAT reading is logical then the problem is likely intermittent. If the reading is less than -30 degrees, unplug the connector. Install a jumper wire between the harness connector signal and ground circuits. The IAT temperature reading on the scan tool should be maxed out at the high end. For example it should be 280 degrees Farenheit or higher. If it is, the wiring is okay, and it may have been the connection. 2. If it isn't install the jumper wire between the IAT signal circuit and the chassis ground.
3. If now the IAT reading on the scan tool is maxed out then check for an open in the IAT ground circuit. If you get no reading at all on the scan tool, it's likely that the sensor signal is open or the 5 volt reference is missing. Check using a DVOM (digital volt ohm meter) for a 5 volt reference. If it's there, then unplug the connector at the PCM and check for continuity on the IAT signal circuit between the PCM connector and the IAT connector.


Hope helps; keep us updated and remember to rate this answer.
8helpful
2answers

P0113

P0113 - Intake Air Temperature Circuit High Input

What does that mean?
The powertrain control module (PCM) monitors the temperature of the air entering the engine. The PCM supplies a 5 volt reference voltage to the Intake Air Temperature (IAT) sensor. The IAT is a thermistor that varies resistance based on temperature. As the temperature increases, resistance decreases. Low temperature results in a high signal voltage. When the PCM sees a signal voltage higher than 5 volts, it sets this P0113 check engine light code.

Potential Symptoms
There will likely be no symptoms other than illumination of the Malfunction Indicator Lamp (MIL - Check Engine Light / Service Engine Soon).

Causes
A code P0113 may mean that one or more of the following has happened:
* Internally failed IAT sensor
* Faulty connection at IAT sensor
* Open in IAT ground circuit or signal circuit
* Short to voltage in IAT signal circuit or reference circuit
* IAT harness and/or wiring routed too close to high-voltage wiring (e.g. alternator, spark plug cables, etc.)
* Faulty PCM (less likely but not impossible)

Possible Solutions
First, if you have access to a scan tool, is there an IAT reading? If the IAT reading is logical then the problem is likely intermittent. If the reading is less than -30 degrees, unplug the connector. Install a jumper wire between the harness connector signal and ground circuits. The IAT temperature reading on the scan tool should be maxed out at the high end. For example it should be 280 degrees Farenheit or higher. If it is, the wiring is okay, and it may have been the connection. If it isn't install the jumper wire between the IAT signal circuit and the chassis ground. If now the IAT reading on the scan tool is maxed out then check for an open in the IAT ground circuit. If you get no reading at all on the scan tool, it's likely that the sensor signal is open or the 5 volt reference is missing. Check using a DVOM (digital volt ohm meter) for a 5 volt reference. If it's there, then unplug the connector at the PCM and check for continuity on the IAT signal circuit between the PCM connector and the IAT connector.

Hope this help (remember rated this).
1helpful
3answers

Diagnostic codes

P0102 OBD-II Trouble Code - Mass Air Flow (MAF) Circuit Low Input

What does that mean?
Basically this means that there is a problem with the Mass Air Flow (MAF) sensor or circuit. A more technical description would be that the MAF circuit had lower than expected voltage (air flow). Other MAF sensor circuit DTC trouble codes are P0100, P0101, P0103, and P0104.

Symptoms
You will likely not notice any serious drivability problems, although there may be symptoms such as a general decrease in power or sluggishness.

Causes
A code P0102 may mean that one or more of the following has happened:
* The MAF may be disconnected, or a wiring connection may be bad
* The MAF may be dirty or otherwise contaminated (Note: if you use a reusable oiled air filter, be careful not to apply too much oil or that can contaminate the MAF).
* The MAF sensor may be faulty
* The vehicle computer may be faulty (very rare)

Possible Solutions
The simplest thing to do is to reset the code and see if it comes back. Then start with the cheapest, easiest repair procedures:
* Verify that the Mass Air Flow Sensor wiring is connected properly and that there are no broken / frayed wires.
* Inspect for any air leaks near the MAF sensor.
* Take the MAF out and clean it using a spray cleaner such as brake cleaner or electrical contact cleaner. Be gentle with the sensor.
* Check the voltage of the MAF sensor (refer to a repair manual for vehicle specific information)
* Replace the MAF sensor.


P0113 - Intake Air Temperature Circuit High Input

What does that mean?
The powertrain control module (PCM) monitors the temperature of the air entering the engine. The PCM supplies a 5 volt reference voltage to the Intake Air Temperature (IAT) sensor. The IAT is a thermistor that varies resistance based on temperature. As the temperature increases, resistance decreases. Low temperature results in a high signal voltage. When the PCM sees a signal voltage higher than 5 volts, it sets this P0113 check engine light code.

Potential Symptoms
There will likely be no symptoms other than illumination of the Malfunction Indicator Lamp (MIL - Check Engine Light / Service Engine Soon).

Causes
A code P0113 may mean that one or more of the following has happened:
* Internally failed IAT sensor
* Faulty connection at IAT sensor
* Open in IAT ground circuit or signal circuit
* Short to voltage in IAT signal circuit or reference circuit
* IAT harness and/or wiring routed too close to high-voltage wiring (e.g. alternator, spark plug cables, etc.)
* Faulty PCM (less likely but not impossible)

Possible Solutions
First, if you have access to a scan tool, is there an IAT reading? If the IAT reading is logical then the problem is likely intermittent. If the reading is less than -30 degrees, unplug the connector. Install a jumper wire between the harness connector signal and ground circuits. The IAT temperature reading on the scan tool should be maxed out at the high end. For example it should be 280 degrees Farenheit or higher. If it is, the wiring is okay, and it may have been the connection. If it isn't install the jumper wire between the IAT signal circuit and the chassis ground. If now the IAT reading on the scan tool is maxed out then check for an open in the IAT ground circuit. If you get no reading at all on the scan tool, it's likely that the sensor signal is open or the 5 volt reference is missing. Check using a DVOM (digital volt ohm meter) for a 5 volt reference. If it's there, then unplug the connector at the PCM and check for continuity on the IAT signal circuit between the PCM connector and the IAT connector.

I really hope help with this (remember rated this).
6helpful
2answers

My 2000 ford focus has codes p0102 and p0113 whats that and what could it be?

P0102 - Mass Air Flow (MAF) Circuit Low Input
The MAF sensor circuit is monitored by the PCM for low air flow (or voltage) input through the comprehensive component monitor (CCM). If during key ON engine running the air flow (or voltage) changes below a minimum calibrated limit, the test fails. MAF sensor disconnected
MAF circuit open to PCM
VPWR open to MAF sensor
PWR GND open to MAF sensor
MAF RTN circuit open to PCM
MAF circuit shorted to GND
Intake air leak (near MAF sensor)
A closed throttle indication [throttle position (TP) sensor system]
Damaged MAF sensor
Damaged PCM
A MAF V PID (MAF PID) reading less than 0.23 volts (Refer to equivalent grams/second chart in GO to Pinpoint Test DC ) in continuous memory or key ON and engine running indicates a hard fault.
P0113 - Intake Air Temperature (IAT) Circuit High Input Indicates the sensor signal is greater than Self-Test maximum. The IAT sensor maximum is 4.6 volts or -50°C (-58°F). Open circuit in harness
Sensor signal short to power
Damaged sensor
Improper harness connection
Damaged PCM
IAT V PID reading greater than 4.6 volts with key ON and engine OFF or during any engine operating mode indicates a hard fault.
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