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.
P0600 Serial Communication Link
P0601 Internal Control Module Memory Check Sum Error
P0602 Control Module Programming Error
P0603 Internal Control Module Keep Alive Memory (KAM) Error
P0604 Internal Control Module Random Access Memory (RAM) Error
P0605 Internal Control Module Read Only Memory (ROM) Error
P0606 ECM/PCM Processor
P0607 Control Module Performance
P0608 Control Module VSS Output “A”
P0609 Control Module VSS Output “B”
P0610 Control Module Vehicle Options Error
P0615 Starter Relay Circuit
P0616 Starter Relay Circuit Low
P0617 Starter Relay Circuit High
P0618 Alternative Fuel Control Module KAM Error
P0619 Alternative Fuel Control Module RAM/ROM Error
P0620 Generator Control Circuit
P0621 Generator Lamp “L” Terminal Control Circuit
P0622 Generator Field “F” Terminal Control Circuit
P0623 Generator Lamp Control Circuit
P0624 Fuel Cap Lamp Control Circuit
P0630 VIN Not Programmed or Mismatch – ECM/PCM
P0631 VIN Not Programmed or Mismatch – TCM
P0635 Power Steering Control Circuit
P0836 Power Steering Control Circuit Low
P0637 Power Steering Control Circuit High
P0638 Throttle Actuator Control Range/Performance (Bank 1)
P0639 Throttle Actuator Control Range/Performance (Bank 2)
P0640 Intake Air Heater Control Circuit
P0645 A/C Clutch Relay Control Circuit
P0646 A/C Clutch Relay Control Circuit Low
P0647 A/C Clutch Relay Control Circuit High
P0648 Immobilizer Lamp Control Circuit (“Immobilizer” pending SAE J1930 approval)
P0649 Speed Control Lamp Control Circuit
P0650 Malfunction Indicator Lamp (ML) Control Circuit
P0654 Engine RPM Output Circuit
P0655 Engine Hot Lamp Output Control Circuit
P0656 Fuel Level Output Circuit
P0660 Intake Manifold Tuning Valve Control Circuit (Bank 1)
P0661 Intake Manifold Tuning Valve Control Circuit Low (Bank 1)
P0662 Intake Manifold Tuning Valve Control Circuit High (Bank 1)
P0663 Intake Manifold Tuning Valve Control Circuit (Bank 2)
P0664 Intake Manifold Tuning Valve Control Circuit Low (Bank 2)
P0665 Intake Manifold Tuning Valve Control Circuit High (Bank 2)
P0100 Mass or Volume Air Flow Circuit
P0101 Mass or Volume Air Flow Circuit Range/Performance Problem
P0102 Mass or Volume Air Flow Circuit Low Input
P0103 Mass or Volume Air Flow Circuit High Input
P0104 Mass or Volume Air Flow Circuit Intermittent
P0105 Manifold Absolute Pressure/Barometric Pressure Circuit
P0106 Manifold Absolute Pressure/Barometric Pressure Circuit Range/Performance Problem
P0107 Manifold Absolute Pressure/Barometric Pressure Circuit Low Input
P0108 Manifold Absolute Pressure/Barometric Pressure Circuit High Input
P0109 Manifold Absolute Pressure/Barometric Pressure Circuit Intermittent
P0110 Intake Air Temperature Circuit
P0111 Intake Air Temperature Circuit Range/Performance Problem
P0112 Intake Air Temperature Circuit Low Input
P0113 Intake Air Temperature Circuit High Input
P0114 Intake Air Temperature Circuit Intermittent
P0115 Engine Coolant Temperature Circuit
P0116 Engine Coolant Temperature Circuit Range/Performance Problem
P0117 Engine Coolant Temperature Circuit Low Input
P0118 Engine Coolant Temperature Circuit High Input
P0119 Engine Coolant Temperature Circuit Intermittent
P0120 Throttle/Pedal Position Sensor/Switch A Circuit
P0121 Throttle/Pedal Position Sensor/Switch A Circuit Range/Performance Problem
P0122 Throttle/Pedal Position Sensor/Switch A Circuit Low Input
P0123 Throttle/Pedal Position Sensor/Switch A Circuit High Input
P0124 Throttle/Pedal Position Sensor/Switch A Circuit Intermittent
P0125 Insufficient Coolant Temperature for Closed Loop Fuel Control
P0126 Insufficient Coolant Temperature for Stable Operation
P0127 Intake Air Temperature Too High
P0128 Coolant Thermostat (Coolant Temperature Below Thermostat Regulating Temperature)
P0130 O2 Sensor Circuit (Bank 1 Sensor 1)
P0131 O2 Sensor Circuit Low Voltage (Bank 1 Sensor 1)
P0132 O2 Sensor Circuit High Voltage (Bank 1 Sensor 1)
P0133 O2 Sensor Circuit Slow Response (Bank 1 Sensor 1)
P0134 O2 Sensor Circuit No Activity Detected (Bank 1 Sensor 1)
P0135 O2 Sensor Heater Circuit (Bank 1 Sensor 1)
P0136 O2 Sensor Circuit Malfunction (Bank 1 Sensor 2)
P0137 O2 Sensor Circuit Low Voltage (Bank 1 Sensor 2)
P0138 O2 Sensor Circuit High Voltage (Bank 1 Sensor 2)
P0139 O2 Sensor Circuit Slow Response (Bank 1 Sensor 2)
P0140 O2 Sensor Circuit No Activity Detected (Bank 1 Sensor 2)
P0141 O2 Sensor Heater Circuit (Bank 1 Sensor 2)
P0142 O2 Sensor Circuit Malfunction (Bank 1 Sensor 3)
P0143 O2 Sensor Circuit Low Voltage (Bank 1 Sensor 3)
P0144 O2 Sensor Circuit High Voltage (Bank 1 Sensor 3)
P0145 O2 Sensor Circuit Slow Response (Bank 1 Sensor 3)
P0146 O2 Sensor Circuit No Activity Detected (Bank 1 Sensor 3)
P0147 O2 Sensor Heater Circuit (Bank 1 Sensor 3)
P0148 Fuel Delivery Error
P0149 Fuel Timing Error
P0150 O2 Sensor Circuit (Bank 2 Sensor 1)
P0151 O2 Sensor Circuit Low Voltage (Bank 2 Sensor 1)
P0152 O2 Sensor Circuit High Voltage (Bank 2 Sensor 1)
P0153 O2 Sensor Circuit Slow Response (Bank 2 Sensor 1)
P0154 O2 Sensor Circuit No Activity Detected (Bank 2 Sensor 1)
P0155 O2 Sensor Heater Circuit (Bank 2 Sensor 1)
P0156 O2 Sensor Circuit Malfunction (Bank 2 Sensor 2)
P0157 O2 Sensor Circuit Low Voltage (Bank 2 Sensor 2)
P0158 O2 Sensor Circuit High Voltage (Bank 2 Sensor 2)
P0159 O2 Sensor Circuit Slow Response (Bank 2 Sensor 2)
P0160 O2 Sensor Circuit No Activity Detected (Bank 2 Sensor 2)
P0161 O2 Sensor Heater Circuit (Bank 2 Sensor 2)
P0162 O2 Sensor Circuit Malfunction (Bank 2 Sensor 3)
P0163 O2 Sensor Circuit Low Voltage (Bank 2 Sensor 3)
P0164 O2 Sensor Circuit High Voltage (Bank 2 Sensor 3)
P0165 O2 Sensor Circuit Slow Response (Bank 2 Sensor 3)
P0166 O2 Sensor Circuit No Activity Detected (Bank 2 Sensor 3)
P0167 O2 Sensor Heater Circuit (Bank 2 Sensor 3)
P0168 Fuel Temperature Too High
P0169 Incorrect Fuel Composition
P0170 Fuel Trim (Bank 1)
P0171 System too Lean (Bank 1)
P0172 System too Rich (Bank 1)
P0173 Fuel Trim Malfunction (Bank 2)
P0174 System too Lean (Bank 2)
P0175 System too Rich (Bank 2)
P0176 Fuel Composition Sensor Circuit
P0177 Fuel Composition Sensor Circuit Range/Performance
P0178 Fuel Composition Sensor Circuit Low Input
P0179 Fuel Composition Sensor Circuit High Input
P0180 Fuel Temperature Sensor A Circuit
P0181 Fuel Temperature Sensor A Circuit Range/Performance
P0182 Fuel Temperature Sensor A Circuit Low Input
P0183 Fuel Temperature Sensor A Circuit High Input
P0184 Fuel Temperature Sensor A Circuit Intermittent
P0185 Fuel Temperature Sensor B Circuit
P0186 Fuel Temperature Sensor B Circuit Range/Performance
P0187 Fuel Temperature Sensor B Circuit Low Input
P0188 Fuel Temperature Sensor B Circuit High Input
P0189 Fuel Temperature Sensor B Circuit Intermittent
P0190 Fuel Rail Pressure Sensor Circuit
P0191 Fuel Rail Pressure Sensor Circuit Range/Performance
P0192 Fuel Rail Pressure Sensor Circuit Low In put
P0193 Fuel Rail Pressure Sensor Circuit High Input
P0194 Fuel Rail Pressure Sensor Circuit Intermittent
P0195 Engine Oil Temperature Sensor
P0196 Engine Oil Temperature Sensor Range/Performance
P0197 Engine Oil Temperature Sensor Low
P0198 Engine Oil Temperature Sensor High
P0199 Engine Oil Temperature Sensor Intermittent