OBD II Code P0116
Engine Coolant Temperature Circuit Range/Performance Problem
Our emissions expert has put together the following information about the P0116 fault code. We have also included diagnostic procedures you can take to your repair shop if the mechanic is having difficulty analyzing the code.
OBD II Fault Code
OBD II P0116
Fault Code Definition
The Engine Coolant Temperature Sensor measures the rise and fall of the Engine Coolant Temperature. This provides critical data needed for the Powertrain Control Module (PCM) to control the Air Fuel Ratio, the Ignition Spark Timing, the cooling fans, and many components of the Emissions Control Systems. Code P0116 indicates a performance problem with the sensor signal to the Powertrain Control Module.
Symptoms
Check Engine Light will illuminate
In many cases, no abnormal symptoms may be noticed
In some cases, the engine may be hard starting and/or get poor fuel economy
Common Problems That Trigger the P0116 Code
Defective Engine Coolant Temperature Sensor
Rusty and/or corroded Engine Coolant
Faulty or corroded Engine Coolant Temperature wiring or connections
Common Misdiagnoses
Engine Coolant Temperature Sensor is replaced when the real cause is rusty coolant
Engine Coolant Temperature Sensor is replaced when the real cause is a poor connection or chafed wiring
Engine Coolant Temperature Sensor is replaced when the real problem is in the Cooling System
Throttle/Pedal Position Sensor/Switch “A” Circuit Low Input
Our emissions expert has put together the following information about the P0122 fault code. We have also included diagnostic procedures you can take to your repair shop if the mechanic is having difficulty analyzing the code.
OBD II Fault Code
OBD II P0122
Fault Code Definition
Code P0122 is triggered when the voltage output from the Throttle/Pedal Position Sensor/Switch to the PCM is too low.
The Throttle Position Sensor/Switch is located on the Throttle Body of the Intake Manifold and the Pedal Position Sensor/Switch is located on the Accelerator Pedal. These sensors provide precise input from the driver’s foot in terms of how much power is needed—and how urgently—from the engine.
As the Throttle Position Sensor is rotated from its base resting position to full acceleration, it sends a increasing voltage signal to the Powertrain Control Module (PCM). This decreasing or increasing voltage signal is used by the PCM to manage the Air Fuel Ratio and Spark Timing of the engine as well as other emissions system components.
Symptoms
Check Engine Light will illuminate
In many cases, no abnormal symptoms may be noticed
In some cases, the engine may be hard starting
In some cases, the engine may hesitate during acceleration
Common Problems That Trigger the P0122 Code
Defective Throttle Position Sensor or Switch
Torn or jammed floor mats
Faulty or corroded Throttle/Pedal Position Sensor/Switch wiring or connections
Common Misdiagnoses
Throttle or Pedal Position Sensor is replaced when the real problem is a poor connection or chafed wiring
Pedal Position Sensor is replaced when the real problem is torn or damaged floor mats
Possible Solutions
Some recommended troubleshooting and repair steps are:
Carefully check the throttle position sensor (TPS), wiring connector, and wiring for breaks, etc. Repair or replace as necessary
Check the voltage at the TPS (refer to a service manual for your vehicle for specific information). If the voltage is too low that is indicative of a problem. Replace if necessary.
If recently replaced the TPS may need to be adjusted. On some vehicles the installation instructions call for the TPS to be properly aligned or adjusted, consult a repair manual for specifics.
If there are no symptoms at all, the problem may be intermittent and clearing the code may resolve the issue temporarily. If this is the case then you should definitely check the wiring to be sure it’s not rubbing on anything, grounding, etc. The code may come back.
Other TPS sensor and circuit related DTCs: P0120, P0121, P0123, P0124
Mass Air Flow (MAF) Sensor
Description:
How does a P0100 code trigger the check engine light? This code will trigger the check engine light under the following conditions:
1. The computer receives an excessively high voltage from the MAF Sensor with the engine not running.
2. The computer receives an excessively low voltage from the MAF Sensor with the engine running.
3. The computer receives a high voltage reading from the MAF Sensor under light-load driving conditions.
Possible Causes:
MAF Sensor circuit open or shorted
Intake air leaks (unmetered air after MAF Sensor)
Defective MAF Sensor
Electronic Control Module (ECM)/Powertrian Control Module (PCM) concern
Diagnostic Help:
Monitor MAF Sensor voltage reading while increasing engine RPM. The MAF Sensor value should increase in proportion to engine speed. If not, first check for air leaks at intake tube, manifold and all vacuum lines. Then test the MAF Sensor circuits for opens and shorts. See our article Automotive Circuit Testing 101, if you need more assistance with this. If concern is determined to be intermittent, wiggle test connectors and wiring to attempt to duplicate concern. You may also use the “Get Help” link if you need specifications or have any other related questions. Remember to refer to an appropriate manual for specific instruction.