I need help. I have the P2127 code on my 2015 Dodge Dart sxt I changed the pedal and sensor and removed and cleaned the throttle body but I am still getting the code. It wont let me erase the code. How do I pinpoint and fix the problem? I assume it saying circuit E low is referring to voltage but how do I determine where the problem actually is?I just bought the car and have driven less then 20 miles before having this problem money is very tight so I am trying to not take it to a shop if I can help it.
artistical1
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9,271 Posts
When you the word circuit in a code description, don't run to the parts store and spend money when you didn't even attempt to diagnose the wiring first. If you don't have a multimeter, go buy that instead, even a cheap harbor freight multimeter is ok. Follow the diagnostic tree below. If you have no idea how to check for continuity, shorts to ground, or shorts between wires, there are you tube videos. You will probably find the problem before you get to GPEC tool step. Just don't backprobe the PCM connector whatever you do. See if you can return that APP sensor which didn't fix anything.
28 - DTC-Based Diagnostics / MODULE, Powertrain Control (PCM), 2.4L / Diagnosis and Testing
P2127-ACCELERATOR PEDAL POSITION SENSOR 2 CIRCUIT LOW
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Theory of Operation
The Electronic Throttle Control (ETC) system uses two Accelerator Pedal Position (APP) Sensors to monitor the accelerator pedal position. The APP Sensors 1 and 2 are integrated into one assembly located at the pedal assembly. Each sensor has a 5 volt reference circuit, a low reference circuit, and a signal circuit. The Powertrain Control Module (PCM) reads the two signals individually and then compares the two signals as a redundant check of the pedal position. One of the sensors will fluctuate somewhere between 0 volts and 5.0 volts and the other sensor will fluctuate somewhere between 0 volts and 2.5 volts. The fluctuation of the two sensors should move proportionately. When operating properly, the voltage reading of the sensor operating on the 2.5 volt scale will always be approximately half of the voltage reading of the sensor on the 5.0 volt scale.
When Monitored and Set Conditions
When Monitored: This diagnostic runs continuously when the following conditions are met:
•With the ignition on.
•Battery voltage greater than 10.4 volts.
Set Conditions:
•The Powertrain Control Module (PCM) detects that the APP Sensor 2 input voltage is below the minimum acceptable value.
Default Actions:
•The MIL light will illuminate.
•The ETC light will flash.
Possible Causes
5-VOLT SUPPLY CIRCUIT OPEN OR SHORTED TO GROUND
APP SENSOR 2 SIGNAL CIRCUIT SHORTED TO GROUND
APP SENSOR 2 SIGNAL CIRCUIT SHORTED TO THE APP SENSOR 1 RETURN CIRCUIT
APP SENSOR 2 SIGNAL CIRCUIT SHORTED TO THE APP SENSOR 2 RETURN CIRCUIT
APP SENSOR 2 SIGNAL CIRCUIT OPEN/HIGH RESISTANCE
APP SENSOR 2 GROUND CIRCUIT OPEN/HIGH RESISTANCE
APP SENSOR
POWERTRAIN CONTROL MODULE (PCM)
Always perform the PRE-DIAGNOSTIC TROUBLESHOOTING PROCEDURE before proceeding. (Refer to 28 - DTC-Based Diagnostics/MODULE, Powertrain Control (PCM) - Standard Procedure).
1.CHECK FOR AN ACTIVE DTC
NOTE: Diagnose and repair any 5-Volt Sensor supply voltage DTCs before continuing with this test.
1. Turn the ignition on.
2. With the scan tool, read DTCs and record on the repair order.
Is the DTC active or pending?
Yes
•Go To 2
No
•Perform the INTERMITTENT CONDITION diagnostic procedure. (Refer to 28 - DTC-Based Diagnostics/MODULE, Powertrain Control (PCM) - Standard Procedure).
2.CHECK THE (K854) 5-VOLT SUPPLY CIRCUIT VOLTAGE
1. Turn the ignition off.
2. Disconnect the APP Sensor harness connector.
3. Turn the ignition on.
4. Measure the voltage on the (K854) 5-Volt Supply circuit at the APP Sensor harness connector.
Is the voltage between 4.9 and 5.2 volts?
Yes
•Go To 3
No
•Repair the (K854) 5-Volt Supply circuit for an open circuit or short to ground.
•Perform the POWERTRAIN VERIFICATION TEST. (Refer to 28 - DTC-Based Diagnostics/MODULE, Powertrain Control (PCM) - Standard Procedure).
3.CHECK THE (K29) APP SENSOR 2 SIGNAL CIRCUIT FOR A SHORT TO GROUN
1. Turn the ignition off.
2. Disconnect the PCM C1 harness connector.
3. Check for continuity between ground and the (K29) APP Sensor 2 Signal circuit at the APP Sensor harness connector.
Is there continuity between ground and the (K29) APP Sensor 2 circuit?
Yes
•Repair the (K29) APP Sensor 2 Signal circuit for a short to ground.
•Perform the POWERTRAIN VERIFICATION TEST. (Refer to 28 - DTC-Based Diagnostics/MODULE, Powertrain Control (PCM) - Standard Procedure).
No
•Go To 4
4.CHECK FOR THE (K29) APP SENSOR 2 SIGNAL CIRCUIT SHORTED TO THE SENSOR GROUND CIRCUITS
1. Check for continuity between the (K29) APP Sensor 2 Signal circuit and the:
•(K400) Sensor Ground circuit at the APP Sensor harness connector.
•(K167) Sensor Ground circuit at the APP Sensor harness connector.
Is there continuity between (K29) APP Sensor 2 Signal circuit and (K400) Sensor Ground circuit or (K167) Sensor Ground circuit?
Yes
•Repair the (K29) APP Sensor 2 Signal circuit for a short to the Sensor Ground circuit that showed continuity.
•Perform the POWERTRAIN VERIFICATION TEST. (Refer to 28 - DTC-Based Diagnostics/MODULE, Powertrain Control (PCM) - Standard Procedure).
No
•Go To
5.CHECK THE (K29) APP SENSOR 2 SIGNAL CIRCUIT FOR AN OPEN/HIGH RESISTANCE
CAUTION:
Do not probe the PCM harness connectors. Probing the PCM harness connectors will damage the PCM terminals resulting in poor terminal to pin connection. Install the GPEC Diagnostic Adaptor to perform the diagnosis.
1. Connect the Adapter, GPEC Diagnostic 10436 .
2. Measure the resistance of the (K29) APP Sensor 2 Signal circuit between the APP Sensor harness connector and the GPEC Adaptor.
Is the resistance below 3.0 Ohms?
Yes
•Go To 6
No
•Repair the (K29) APP Sensor 2 Signal circuit for an open or high resistance.
•Perform the POWERTRAIN VERIFICATION TEST. (Refer to 28 - DTC-Based Diagnostics/MODULE, Powertrain Control (PCM) - Standard Procedure).
6.CHECK THE (K400) APP SENSOR GROUND CIRCUIT FOR AN OPEN/HIGH RESISTANCE
1. Measure the resistance of the (K400) APP Sensor Ground circuit between the APP Sensor harness connector and the GPEC Adaptor.
Is the resistance below 3.0 Ohms?
Yes
•Go To 7
No
•Repair the (K400) APP Sensor Ground circuit for an open or high resistance.
•Perform the POWERTRAIN VERIFICATION TEST. (Refer to 28 - DTC-Based Diagnostics/MODULE, Powertrain Control (PCM) - Standard Procedure).
7.CHECK THE ACCELERATOR PEDAL POSITION SENSOR
1. Reconnect the PCM C1 harness connector.
2. Connect a jumper between the (K854) 5-Volt Supply circuit and the (K29) APP Sensor 2 Signal circuit at the APP Sensor harness connector.
3. Turn the ignition on.
4. With the scan tool, read DTCs.
NOTE: The P2128–ACCELERATOR PEDAL POSITION SENSOR 2 CIRCUIT HIGH DTC should display as active or pending with the jumper in place.
Does the scan tool display as described above?
Yes
•Replace the Accelerator Pedal Position Sensor in accordance with the Service Information.
•Perform the POWERTRAIN VERIFICATION TEST. (Refer to 28 - DTC-Based Diagnostics/MODULE, Powertrain Control (PCM) - Standard Procedure).
No
•Go To 8
8.CHECK RELATED PCM AND COMPONENT CONNECTIONS
1. Perform any Service Bulletins that apply.
2. Disconnect all PCM harness connectors.
3. Disconnect all related in-line harness connections (if equipped).
4. Disconnect the related component harness connectors.
5. Inspect harness connectors, component connectors, and all male and female terminals for the following conditions:
•Proper connector installation.
•Damaged connector locks.
•Corrosion.
•Other signs of water intrusion.
•Weather seal damage (if equipped).
•Bent terminals.
•Overheating due to a poor connection (terminal may be discolored due to excessive current draw).
•Terminals that have been pushed back into the connector cavity.
•Check for spread terminals and verify proper terminal tension.
Repair any conditions that are found.
6. Reconnect all PCM harness connectors. Be certain that all harness connectors are fully seated and the connector locks are fully engaged.
7. Reconnect all in-line harness connectors (if equipped). Be certain that all connectors are fully seated and the connector locks are fully engaged.
8. Reconnect all related component harness connectors. Be certain that all connectors are fully seated and the connector locks are fully engaged.
9. With the scan tool, erase DTCs.
10. Test drive or operate the vehicle in accordance with the when monitored and set conditions.
11. With the scan tool, read DTCs.
Did the DTC return?
Yes
•Replace the Powertrain Control Module in accordance with the Service information. (Refer to 08 - Electrical/8E - Electronic Control Modules/MODULE, Powertrain Control - Removal) .
•Perform the POWERTRAIN VERIFICATION TEST. (Refer to 28 - DTC-Based Diagnostics/MODULE, Powertrain Control (PCM) - Standard Procedure).
28 - DTC-Based Diagnostics / MODULE, Powertrain Control (PCM), 2.4L / Diagnosis and Testing
P2127-ACCELERATOR PEDAL POSITION SENSOR 2 CIRCUIT LOW
Theory of Operation
The Electronic Throttle Control (ETC) system uses two Accelerator Pedal Position (APP) Sensors to monitor the accelerator pedal position. The APP Sensors 1 and 2 are integrated into one assembly located at the pedal assembly. Each sensor has a 5 volt reference circuit, a low reference circuit, and a signal circuit. The Powertrain Control Module (PCM) reads the two signals individually and then compares the two signals as a redundant check of the pedal position. One of the sensors will fluctuate somewhere between 0 volts and 5.0 volts and the other sensor will fluctuate somewhere between 0 volts and 2.5 volts. The fluctuation of the two sensors should move proportionately. When operating properly, the voltage reading of the sensor operating on the 2.5 volt scale will always be approximately half of the voltage reading of the sensor on the 5.0 volt scale.
When Monitored and Set Conditions
When Monitored: This diagnostic runs continuously when the following conditions are met:
•With the ignition on.
•Battery voltage greater than 10.4 volts.
Set Conditions:
•The Powertrain Control Module (PCM) detects that the APP Sensor 2 input voltage is below the minimum acceptable value.
Default Actions:
•The MIL light will illuminate.
•The ETC light will flash.
Possible Causes
5-VOLT SUPPLY CIRCUIT OPEN OR SHORTED TO GROUND
APP SENSOR 2 SIGNAL CIRCUIT SHORTED TO GROUND
APP SENSOR 2 SIGNAL CIRCUIT SHORTED TO THE APP SENSOR 1 RETURN CIRCUIT
APP SENSOR 2 SIGNAL CIRCUIT SHORTED TO THE APP SENSOR 2 RETURN CIRCUIT
APP SENSOR 2 SIGNAL CIRCUIT OPEN/HIGH RESISTANCE
APP SENSOR 2 GROUND CIRCUIT OPEN/HIGH RESISTANCE
APP SENSOR
POWERTRAIN CONTROL MODULE (PCM)
Always perform the PRE-DIAGNOSTIC TROUBLESHOOTING PROCEDURE before proceeding. (Refer to 28 - DTC-Based Diagnostics/MODULE, Powertrain Control (PCM) - Standard Procedure).
1.CHECK FOR AN ACTIVE DTC
NOTE: Diagnose and repair any 5-Volt Sensor supply voltage DTCs before continuing with this test.
1. Turn the ignition on.
2. With the scan tool, read DTCs and record on the repair order.
Is the DTC active or pending?
Yes
•Go To 2
No
•Perform the INTERMITTENT CONDITION diagnostic procedure. (Refer to 28 - DTC-Based Diagnostics/MODULE, Powertrain Control (PCM) - Standard Procedure).
2.CHECK THE (K854) 5-VOLT SUPPLY CIRCUIT VOLTAGE
1. Turn the ignition off.
2. Disconnect the APP Sensor harness connector.
3. Turn the ignition on.
4. Measure the voltage on the (K854) 5-Volt Supply circuit at the APP Sensor harness connector.
Is the voltage between 4.9 and 5.2 volts?
Yes
•Go To 3
No
•Repair the (K854) 5-Volt Supply circuit for an open circuit or short to ground.
•Perform the POWERTRAIN VERIFICATION TEST. (Refer to 28 - DTC-Based Diagnostics/MODULE, Powertrain Control (PCM) - Standard Procedure).
3.CHECK THE (K29) APP SENSOR 2 SIGNAL CIRCUIT FOR A SHORT TO GROUN
1. Turn the ignition off.
2. Disconnect the PCM C1 harness connector.
3. Check for continuity between ground and the (K29) APP Sensor 2 Signal circuit at the APP Sensor harness connector.
Is there continuity between ground and the (K29) APP Sensor 2 circuit?
Yes
•Repair the (K29) APP Sensor 2 Signal circuit for a short to ground.
•Perform the POWERTRAIN VERIFICATION TEST. (Refer to 28 - DTC-Based Diagnostics/MODULE, Powertrain Control (PCM) - Standard Procedure).
No
•Go To 4
4.CHECK FOR THE (K29) APP SENSOR 2 SIGNAL CIRCUIT SHORTED TO THE SENSOR GROUND CIRCUITS
1. Check for continuity between the (K29) APP Sensor 2 Signal circuit and the:
•(K400) Sensor Ground circuit at the APP Sensor harness connector.
•(K167) Sensor Ground circuit at the APP Sensor harness connector.
Is there continuity between (K29) APP Sensor 2 Signal circuit and (K400) Sensor Ground circuit or (K167) Sensor Ground circuit?
Yes
•Repair the (K29) APP Sensor 2 Signal circuit for a short to the Sensor Ground circuit that showed continuity.
•Perform the POWERTRAIN VERIFICATION TEST. (Refer to 28 - DTC-Based Diagnostics/MODULE, Powertrain Control (PCM) - Standard Procedure).
No
•Go To
5.CHECK THE (K29) APP SENSOR 2 SIGNAL CIRCUIT FOR AN OPEN/HIGH RESISTANCE
CAUTION:
Do not probe the PCM harness connectors. Probing the PCM harness connectors will damage the PCM terminals resulting in poor terminal to pin connection. Install the GPEC Diagnostic Adaptor to perform the diagnosis.
1. Connect the Adapter, GPEC Diagnostic 10436 .
2. Measure the resistance of the (K29) APP Sensor 2 Signal circuit between the APP Sensor harness connector and the GPEC Adaptor.
Is the resistance below 3.0 Ohms?
Yes
•Go To 6
No
•Repair the (K29) APP Sensor 2 Signal circuit for an open or high resistance.
•Perform the POWERTRAIN VERIFICATION TEST. (Refer to 28 - DTC-Based Diagnostics/MODULE, Powertrain Control (PCM) - Standard Procedure).
6.CHECK THE (K400) APP SENSOR GROUND CIRCUIT FOR AN OPEN/HIGH RESISTANCE
1. Measure the resistance of the (K400) APP Sensor Ground circuit between the APP Sensor harness connector and the GPEC Adaptor.
Is the resistance below 3.0 Ohms?
Yes
•Go To 7
No
•Repair the (K400) APP Sensor Ground circuit for an open or high resistance.
•Perform the POWERTRAIN VERIFICATION TEST. (Refer to 28 - DTC-Based Diagnostics/MODULE, Powertrain Control (PCM) - Standard Procedure).
7.CHECK THE ACCELERATOR PEDAL POSITION SENSOR
1. Reconnect the PCM C1 harness connector.
2. Connect a jumper between the (K854) 5-Volt Supply circuit and the (K29) APP Sensor 2 Signal circuit at the APP Sensor harness connector.
3. Turn the ignition on.
4. With the scan tool, read DTCs.
NOTE: The P2128–ACCELERATOR PEDAL POSITION SENSOR 2 CIRCUIT HIGH DTC should display as active or pending with the jumper in place.
Does the scan tool display as described above?
Yes
•Replace the Accelerator Pedal Position Sensor in accordance with the Service Information.
•Perform the POWERTRAIN VERIFICATION TEST. (Refer to 28 - DTC-Based Diagnostics/MODULE, Powertrain Control (PCM) - Standard Procedure).
No
•Go To 8
8.CHECK RELATED PCM AND COMPONENT CONNECTIONS
1. Perform any Service Bulletins that apply.
2. Disconnect all PCM harness connectors.
3. Disconnect all related in-line harness connections (if equipped).
4. Disconnect the related component harness connectors.
5. Inspect harness connectors, component connectors, and all male and female terminals for the following conditions:
•Proper connector installation.
•Damaged connector locks.
•Corrosion.
•Other signs of water intrusion.
•Weather seal damage (if equipped).
•Bent terminals.
•Overheating due to a poor connection (terminal may be discolored due to excessive current draw).
•Terminals that have been pushed back into the connector cavity.
•Check for spread terminals and verify proper terminal tension.
Repair any conditions that are found.
6. Reconnect all PCM harness connectors. Be certain that all harness connectors are fully seated and the connector locks are fully engaged.
7. Reconnect all in-line harness connectors (if equipped). Be certain that all connectors are fully seated and the connector locks are fully engaged.
8. Reconnect all related component harness connectors. Be certain that all connectors are fully seated and the connector locks are fully engaged.
9. With the scan tool, erase DTCs.
10. Test drive or operate the vehicle in accordance with the when monitored and set conditions.
11. With the scan tool, read DTCs.
Did the DTC return?
Yes
•Replace the Powertrain Control Module in accordance with the Service information. (Refer to 08 - Electrical/8E - Electronic Control Modules/MODULE, Powertrain Control - Removal) .
•Perform the POWERTRAIN VERIFICATION TEST. (Refer to 28 - DTC-Based Diagnostics/MODULE, Powertrain Control (PCM) - Standard Procedure).
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