Home/Saturn/ION/Saturn ION I (2003-2007)/Repair manual/Testing & Diagnostics/Engine Controls - 2.2L (L61) - DTC P2101 - DTC P2176: Overv…
Contents Wiring diagrams Section: Testing & Diagnostics All sections

Engine Controls - 2.2L (L61) - DTC P2101 - DTC P2176: Overview Saturn ION I

Testing & Diagnostics 1 illustration ~500 words

Scheme 63

Scheme 63: DTC P2101

Test Description

The numbers below refer to the step numbers on the diagnostic table.

  1. 8: The throttle valve is spring loaded in a slightly open position and should move in either direction without binding. The throttle valve should always be under spring pressure.
  2. 11: When the ignition is turned ON, the ECM operates the throttle control motor to verify the integrity of the system prior to start-up. This can be seen by the momentary flash of the test lamp as the ignition is turned ON.
StepActionValuesYesNo
Schematic Reference: Engine Controls Schematics Connector End View Reference: Engine Control Module (ECM) Connector End Views or Engine Controls Connector End Views
1Did you perform the Diagnostic System Check - Vehicle?Go to Step 2Go to Diagnostic System Check - Vehicle in Vehicle DTC Information
2Are DTCs P0120, P0220, P2120, P2125, P2135, P2138 also set?Go to Diagnostic Trouble Code (DTC) List - Vehicle in Vehicle DTC InformationGo to Step 3
3IMPORTANT: The throttle angle and pedal angle may not correspond during this procedure. Turn ON the ignition, with the engine OFF. Observe the Throttle Position (TP) Sensor 1 and 2 Angle parameters. Apply and release the accelerator pedal several times. Does the TP Sensor 1 and 2 Angle parameters increase as the pedal is applied and decrease as the pedal is released?Go to Step 4Go to Step 5
4Observe the Freeze Frame/Failure Records for this DTC. Start the engine. Operate the vehicle within the Conditions for Running the DTC. You may also operate the vehicle within the conditions that you observed from the Freeze Frame/Failure Records. Did the DTC fail this ignition?Go to Step 5Go to Diagnostic Aids
5Turn ON the ignition, with the engine OFF. Probe both sides of the ECM/ETC fuse with a test lamp. Does the test lamp illuminate on both sides of the fuse?Go to Step 6Go to Step 15
6Turn OFF the ignition. Probe both sides of the ECM/ETC fuse with a test lamp. Does the test lamp illuminate on both sides of the fuse?Go to Step 22Go to Step 7
7Turn OFF the ignition. Disconnect the engine control module (ECM) connector containing the TAC ignition 1 voltage circuit. Turn ON the ignition. Measure the resistance of the ECM/ETC ignition 1 voltage circuit with a DMM Is the resistance less than the specified value?5 ohmsGo to Step 8Go to Step 23
8Connect the ECM. Turn OFF the ignition. Inspect the throttle body for the following conditions: A throttle valve that is NOT in the rest position A throttle valve that is binding open or closed A throttle valve that is free to move open or closed WITHOUT spring pressure Refer to Diagnostic Aids. Did you find any of these conditions with the throttle body?Go to Step 24Go to Step 9
9IMPORTANT: The test lamp may momentarily flash when testing these circuits. This is considered normal. Disconnect the throttle body harness connector. Turn ON the ignition, with the engine OFF. Probe the throttle actuator control (TAC) motor control 1 and 2 circuits with the test lamp connected to ground. Did the test lamp illuminate and remain illuminated on either circuit?Go to Step 12Go to Step 10
10IMPORTANT: The test lamp may momentarily flash when testing these circuits. This is considered normal. Probe the TAC motor control 1 and 2 circuits with the test lamp connected to battery positive.Did the test lamp illuminate and remain illuminated on either circuit?Go to Step 13Go to Step 11
11Turn OFF the ignition. Connect the jumper wires between the TP sensors harness connector and the corresponding terminals. Connect the test lamp between the TAC motor control 1 and battery ground. Observe the test lamp as you turn ON the ignition. Does the test lamp flash ON and then turn OFF?Go to Step 12Go to Step 14
12Turn OFF the ignition. Disconnect the ECM connector that contains the TAC motor control circuits. Turn ON the ignition, with the engine OFF. Probe the TAC motor control 1 and 2 circuits with the test lamp connected to ground. Does the test lamp illuminate?Go to Step 20Go to Step 19
13Turn OFF the ignition. Disconnect the ECM connector that contains the TAC motor control circuits. Probe the TAC motor control 1 and 2 circuits with the test lamp connected to battery positive. Does the test lamp illuminate?Go to Step 21Go to Step 19
14Turn OFF the ignition. Disconnect the ECM connector that contains the TAC motor control circuits. Test the TAC motor control 1 and 2 circuits for an open or high resistance. Repair the circuit as necessary. Refer to Wiring Repairs in Wiring Systems. Did you find and correct the condition?Go to Step 26Go to Step 19
15Test the ETC ignition 1 voltage circuit for a short to ground. Refer to Circuit Testing and Wiring Repairs in Wiring Systems. Did you find and correct the condition?Go to Step 26Go to Step 17
16Test the motor control 1 circuit for a short to ground. Refer to Circuit Testing and Wiring Repairs in Wiring Systems. Did you find and correct the condition?Go to Step 26Go to Step 24
17Turn OFF the ignition. Disconnect the ECM connector that contains the TAC motor control circuits. Test the TAC motor control 1 and 2 circuits for an open or high resistance. Repair the circuit as necessary. Refer to Wiring Repairs in Wiring Systems. Did you find and correct the condition?Go to Step 26Go to Step 18
18Test for a poor connection or terminal tension at the throttle body connector. Refer to Testing for Intermittent Conditions and Poor Connections and Connector Repairs in Wiring Systems. Did you find and correct the condition?Go to Step 26Go to Step 24
19Test for a poor connection or terminal tension at the ECM. Refer to Testing for Intermittent Conditions and Poor Connections and Connector Repairs in Wiring Systems. Did you find and correct the condition?Go to Step 26Go to Step 24
20Repair the short to voltage on the circuit where the test lamp remained illuminated. Refer to Wiring Repairs in Wiring Systems. Did you complete the repair?Go to Step 26
21Repair the short to ground on the circuit where the test lamp remained illuminated. Refer to Wiring Repairs in Wiring Systems. Did you complete the repair?Go to Step 26
22Repair the short to voltage on the ETC ignition 1 voltage circuit. Refer to Wiring Repairs in Wiring Systems. Did you complete the repair?Go to Step 26
23Repair the open or high resistance in the ETC ignition 1 voltage circuit. Refer to Wiring Repairs in Wiring Systems. Did you complete the repair?Go to Step 26
24Replace the throttle body assembly. Refer to Throttle Body Assembly Replacement . Did you complete the replacement?Go to Step 26
25Replace the ECM. Refer to Control Module References in Computer/Integrating Systems for replacement, setup, and programming. Did you complete the replacement?Go to Step 26
26Clear the DTCs with a scan tool. Turn OFF the ignition for 30 seconds. Start the engine. Operate the vehicle within the Conditions for Running the DTC. You may also operate the vehicle within the conditions that you observed from the Freeze Frame/Failure Records. Did the DTC fail this ignition?Go to Step 2Go to Step 27
27Observe the Capture Info with a scan tool. Are there any DTCs that have not been diagnosed?Go to Diagnostic Trouble Code (DTC) List - Vehicle in Vehicle DTC InformationSystem OK
IMPORTANT
The throttle angle and pedal angle may not correspond during this procedure.
IMPORTANT
The test lamp may momentarily flash when testing these circuits. This is considered normal.
IMPORTANT
The test lamp may momentarily flash when testing these circuits. This is considered normal.

DTC P2101

The number below refers to the step number on the diagnostic table.

  1. 8: More than one ETC system related DTC may set. This is due to the many redundant tests run continuously on this system. Locating and repairing one individual condition may correct more than one DTC. Keep this in mind when reviewing captured DTC info.
StepActionValuesYesNo
Schematic Reference: Engine Controls Schematics Connector End View Reference: Engine Control Module (ECM) Connector End Views or Engine Controls Connector End Views
1Did you perform the Diagnostic System Check - Vehicle?Go to Step 2Go to Diagnostic System Check - Vehicle in Vehicle DTC Information
2Are any other DTCs set?Go to Diagnostic Trouble Code (DTC) List - Vehicle in Vehicle DTC InformationGo to Step 3
3Turn OFF the ignition for 15 seconds. Turn ON the ignition, with the engine OFF. Allow the pedal to rest at idle stop for 20 seconds. Observe the indicated throttle position parameter with a scan tool. Does the scan tool indicate throttle position within the specified values?10.8-23.2%Go to Step 6Go to Step 4
4Remove the throttle body assembly. Refer to Throttle Body Assembly Replacement . Did you find any obstructions preventing the throttle blade from returning to the default position?Go to Step 5Go to Step 6
5Remove the obstruction. Did you complete the action?Go to Step 7
6Replace the throttle body assembly. Refer to Throttle Body Assembly Replacement . Did you complete the replacement?Go to Step 7
7Clear the DTCs with a scan tool. Turn OFF the ignition for 30 seconds. Start the engine. Operate the vehicle within the Conditions for Running the DTC. You may also operate the vehicle within the conditions that you observed from the Freeze/Frame Failure Records. Did the DTC fail this ignition?Go to Step 2Go to Step 8
8Observe the Capture Info with a scan tool. Are there any DTCs that have not been diagnosed?Go to Diagnostic Trouble Code (DTC) List - Vehicle in Vehicle DTC InformationSystem OK

DTC P2119

The numbers below refer to the step numbers on the diagnostic table.

  1. 6: This step determines the integrity of the 5-volt reference and ground circuits of the TP sensors.
  2. 7: This step determines if the 5-volt reference circuit or the sensor ground circuit is the cause of the DTC.
  3. 8: If the scan tool displays 100 percent for the TP sensor 1 and the TP sensor 2 angle, this indicates that the TP sensor signal circuits are not the cause of the DTC.
  4. 9: This step tests for excessive resistance in the TP sensor 5-volt reference circuit between the TP sensor harness connector and the ECM harness connector.
  5. 10: This step tests for excessive resistance in the TP sensor ground circuit between the TP sensor harness connector and the ECM harness connector.
  6. 11: This step tests for the TP sensor signal circuits for being shorted to another circuit in the ECM wiring harness between the ECM and the TP sensor wiring harness.
  7. 16: When the ECM detects a condition within the throttle control system, more than one related DTC may set. This is due to the many redundant tests run continuously on this system. Locating and repairing one individual condition may correct more than one DTC. Keep this in mind when reviewing captured DTC info.
StepActionValue(s)YesNo
1Did you perform the Diagnostic System Check - Vehicle?Go to Step 2Go to Diagnostic System Check - Vehicle in Vehicle DTC Information
2Observe the DTC information with a scan tool. Is DTC P0641 or P0651 also set?Go to Diagnostic Trouble Code (DTC) List - Vehicle in Vehicle DTC InformationGo to Step 3
3Turn ON the ignition, with the engine OFF. Monitor the Throttle Position (TP) Sensors Agree/Disagree parameter using the scan tool. Does the scan tool indicate Disagree?Go to Step 6Go to Step 4
4Remove the resonator assembly from the throttle body assembly. IMPORTANT: Removing the TAC fuse will set additional DTCs. Remove the TAC fuse. Open the throttle blade to wide open throttle (WOT) by hand and then return it to closed throttle. Stop briefly at approximately 25 percent, 50 percent, 75 percent and 100 percent in each direction. Test the Throttle Sensors Disagree parameter at each stop. Does the scan tool indicate Disagree while rotating the throttle blade?Go to Step 6Go to Step 5
5Observe the Freeze Frame/Failure Records for this DTC. Turn OFF the ignition for 30 seconds. Start the engine. Operate the vehicle within the Conditions for Running the DTC. You may also operate the vehicle within the conditions that you observed from the Freeze/Frame Failure Records. Does the DTC fail this ignition?Go to Step 15Go to Intermittent Conditions
6Disconnect the TP sensor electrical connector. Turn ON the ignition, with the engine OFF. Measure the voltage between the 5-volt reference circuit of TP sensor 1 and the TP sensor 1 low reference circuit with a DMM. Measure the voltage between the 5-volt reference circuit of TP sensor 2 and the TP sensor 2 low reference circuit with a DMM. Does the DMM display a voltage within the specified range for both measurements?4.9-5.1 VGo to Step 8Go to Step 7
7Test the voltage on the 5-volt reference circuit for TP sensor 1 and TP sensor 2 to a battery ground with a DMM. Does the DMM display a voltage within the specified range?4.9-5.1 VGo to Step 10Go to Step 9
8Observe the TP sensor 1 and TP sensor 2 angle on the scan tool. Does the scan tool indicate both sensors at the specified value?100%Go to Step 12Go to Step 9
9Test the 5-volt reference circuit of the TP sensor 1 and TP sensor 2 for high resistance. Refer to Circuit Testing and Wiring Repairs in Wiring Systems. Did you find and correct the condition?Go to Step 15Go to Step 10
10Test the low reference circuit of the TP sensor 1 and TP sensor 2 for high resistance. Refer to Circuit Testing and Wiring Repairs in Wiring Systems. Did you find and correct the condition?Go to Step 15Go to Step 11
11Test the signal circuit of the TP sensor 1 and TP sensor 2 for high resistance. Did you find and correct the condition?Go to Step 15Go to Step 13
12Replace the throttle body assembly. Refer to Throttle Body Assembly Replacement . Did you complete the replacement?Go to Step 15
13Test for poor connections and/or terminal tension at the TP sensor and at the engine control module (ECM). Refer to Testing for Intermittent Conditions and Poor Connections in Wiring Systems. Did you find and correct the condition?Go to Step 15Go to Step 14
14Replace the ECM. Refer to Control Module References in Computer/Integrating Systems for replacement, setup, and programming. Did you complete the replacement?Go to Step 15
15Clear the DTCs with a scan tool. Turn OFF the ignition for 30 seconds. Start the engine. Operate the vehicle within the Conditions for Running the DTC. You may also operate the vehicle within the conditions that you observed from the Freeze/Frame Failure Records. Did the DTC fail this ignition?Go to Step 2Go to Step 16
16Observe the Capture Info with a scan tool. Are there any DTCs that have not been diagnosed?Go to Diagnostic Trouble Code (DTC) List - Vehicle in Vehicle DTC InformationSystem OK
IMPORTANT
Removing the TAC fuse will set additional DTCs.

DTC P2135

The number below refers to the step number on the diagnostic table.

  1. 2: Any circuit faults on either APP sensor 1 or 2 will set one of the DTCs listed. Refer to the appropriate table for diagnosis.
StepActionValuesYesNo
Schematic Reference: Engine Controls Schematics Connector End View Reference: Engine Control Module (ECM) Connector End Views or Engine Controls Connector End Views
1Did you perform the Diagnostic System Check - Vehicle?Go to Step 2Go to Diagnostic System Check - Vehicle in Vehicle DTC Information
2Observe the DTC information with a scan tool. Is DTC P0120, P0220, P0641, P0651, P2120, or P2125 also set?Go to Diagnostic Trouble Code (DTC) List - Vehicle in Vehicle DTC InformationGo to Step 3
3Turn OFF the ignition. Disconnect the accelerator pedal position (APP) sensor electrical connector. Disconnect the engine control module (ECM). Measure the resistance of the following circuits for each of the APP sensors with a DMM: The low reference circuit The signal circuit The 5-volt reference circuit Did any of the circuits measure more than the specified value?5 ohmsGo to Step 5Go to Step 4
4Test for a short between any of the circuits in the APP sensor harness. Repair the circuit as necessary. Refer to Wiring Repairs in Wiring Systems. Did you find and correct the condition?Go to Step 7Go to Step 6
5Repair the high resistance in the circuit. Refer to Wiring Repairs in Wiring Systems. Did you complete the repair?Go to Step 7
6Replace the APP sensor. Refer to Accelerator Controls Pedal Replacement . Did you complete the replacement?Go to Step 7
7Clear the DTCs with a scan tool. Turn OFF the ignition for 30 seconds. Start the engine. Operate the vehicle within the Conditions for Running the DTC. You may also operate the vehicle within the conditions that you observed from the Freeze/Frame Failure Records. Did the DTC fail this ignition?Go to Step 2Go to Step 8
8Observe the Capture Info with a scan tool. Are there any DTCs that have not been diagnosed?Go to Diagnostic Trouble Code (DTC) List - Vehicle in Vehicle DTC InformationSystem OK

DTC P2138

The numbers below refer to the step numbers on the diagnostic table.

  1. 8: The throttle valve is spring loaded in a slightly open position and should move in either direction without binding. The throttle valve should always be under spring pressure.
  2. 11: When the ignition is turned ON, the PCM operates the throttle control motor to verify the integrity of the system prior to start-up. This can be seen by the momentary flash of the test lamp as the ignition is turned ON.
StepActionValuesYesNo
Schematic Reference: Engine Controls Schematics Connector End View Reference: Engine Control Module (ECM) Connector End Views or Engine Controls Connector End Views
1Did you perform the Diagnostic System Check - Vehicle?Go to Step 2Go to Diagnostic System Check - Vehicle in Vehicle DTC Information
2Are DTCs P0120, P0220, P2120, P2125, P2135, P2138 also set?Go to Diagnostic Trouble Code (DTC) List - Vehicle in Vehicle DTC InformationGo to Step 3
3IMPORTANT: The throttle angle and pedal angle may not correspond during this procedure. Turn ON the ignition, with the engine OFF. Observe the Throttle Position (TP) Sensor 1 and 2 Angle parameters. Apply and release the accelerator pedal several times. Does the TP Sensor 1 and 2 Angle parameters increase as the pedal is applied and decrease as the pedal is released?Go to Step 4Go to Step 5
4Observe the Freeze Frame/Failure Records for this DTC. Start the engine. Operate the vehicle within the Conditions for Running the DTC. You may also operate the vehicle within the conditions that you observed from the Freeze Frame/Failure Records. Did the DTC fail this ignition?Go to Step 5Go to Diagnostic Aids
5Turn ON the ignition, with the engine OFF. Probe both sides of the ECM/ETC fuse with a test lamp. Does the test lamp illuminate on both sides of the fuse?Go to Step 6Go to Step 15
6Turn OFF the ignition. Probe both sides of the ECM/ETC fuse with a test lamp. Does the test lamp illuminate on both sides of the fuse?Go to Step 22Go to Step 7
7Turn OFF the ignition. Disconnect the engine control module (ECM) connector containing the throttle actuator control (TAC) ignition 1 voltage circuit. Turn ON the ignition. Measure the resistance of the ECM/ETC ignition 1 voltage circuit with a DMM. Is the resistance less than the specified value?5 ohmsGo to Step 8Go to Step 23
8Turn OFF the ignition. Inspect the throttle body for the following conditions: A throttle valve that is NOT in the rest position A throttle valve that is binding open or closed A throttle valve that is free to move open or closed WITHOUT spring pressure Refer to Diagnostic Aids Did you find any of these conditions with the throttle body?Go to Step 24Go to Step 9
9IMPORTANT: The test lamp may momentarily flash when testing these circuits. This is considered normal. Disconnect the throttle body harness connector. Turn ON the ignition, with the engine OFF. Probe the TAC motor control 1 and 2 circuits with the test lamp connected to ground. Did the test lamp illuminate and remain illuminated on either circuit?Go to Step 12Go to Step 10
10IMPORTANT: The test lamp may momentarily flash when testing these circuits. This is considered normal. Probe the TAC motor control 1 and 2 circuits with the test lamp connected to battery positive.Did the test lamp illuminate and remain illuminated on either circuit?Go to Step 13Go to Step 11
11Turn OFF the ignition. Connect the jumper wires between the TP sensor harness connector and the corresponding terminals. Connect the test lamp between the TAC motor control 1 and battery ground. Observe the test lamp as you turn ON the ignition. Does the test lamp flash ON and then turn OFF?Go to Step 12Go to Step 14
12Turn OFF the ignition. Disconnect the ECM connector that contains the TAC motor control circuits. Turn ON the ignition, with the engine OFF. Probe the TAC motor control 1 and 2 circuits with the test lamp connected to ground. Does the test lamp illuminate?Go to Step 20Go to Step 19
13Turn OFF the ignition. Disconnect the ECM connector that contains the TAC motor control circuits. Probe the TAC motor control 1 and 2 circuits with the test lamp connected to battery positive. Does the test lamp illuminate?Go to Step 21Go to Step 19
14Turn OFF the ignition. Disconnect the ECM connector that contains the TAC motor controls circuits. Test TAC motor control 1 and 2 circuits for an open or high resistance. Repair the circuit as necessary. Refer to Wiring Repairs in Wiring Systems. Did you find and correct the condition?Go to Step 26Go to Step 19
15Test the ETC ignition 1 voltage circuit for a short to ground. Refer to Circuit Testing and Wiring Repairs in Wiring Systems. Did you find and correct the condition?Go to Step 26Go to Step 16
16Test the motor control 1 circuit for a short to ground. Refer to Circuit Testing and Wiring Repairs in Wiring Systems. Did you find and correct the condition?Go to Step 26Go to Step 24
17Turn OFF the ignition. Disconnect the ECM connector that contains the TAC motor control circuits. Test the TAC motor control 1 and 2 circuits for an open or high resistance. Repair the circuit as necessary. Refer to Wiring Repairs in Wiring Systems. Did you find and correct the condition?Go to Step 26Go to Step 18
18Test for a poor connection or terminal tension at the throttle body connector. Refer to Testing for Intermittent Conditions and Poor Connections and Connector Repairs in Wiring Systems. Did you find and correct the condition?Go to Step 26Go to Step 24
19Test for a poor connection or terminal tension at the ECM. Refer to Testing for Intermittent Conditions and Poor Connections and Connector Repairs in Wiring Systems. Did you find and correct the condition?Go to Step 26Go to Step 24
20Repair the short to voltage on the circuit where the test lamp remained illuminated. Refer to Wiring Repairs in Wiring Systems. Did you complete the repair?Go to Step 26
21Repair the short to ground on the circuit where the test lamp remained illuminated. Refer to Wiring Repairs in Wiring Systems. Did you complete the repair?Go to Step 26
22Repair the short to voltage on the ETC ignition 1 voltage circuit. Refer to Wiring Repairs in Wiring Systems. Did you complete the repair?Go to Step 26
23Repair the open or high resistance in the ETC ignition 1 voltage circuit. Refer to Wiring Repairs in Wiring Systems. Did you complete the repair?Go to Step 26
24Replace the throttle body assembly. Refer to Throttle Body Assembly Replacement . Did you complete the replacement?Go to Step 26
25Replace the ECM. Refer to Control Module References in Computer/Integrating Systems for replacement, setup, and programming. Did you complete the replacement?Go to Step 26
26Clear the DTCs with a scan tool. Turn OFF the ignition for 30 seconds. Start the engine. Operate the vehicle within the Conditions for Running the DTC. You may also operate the vehicle within the conditions that you observed from the Freeze Frame/Failure Records. Did the DTC fail this ignition?Go to Step 2Go to Step 27
27Observe the Capture Info with a scan tool. Are there any DTCs that have not been diagnosed?Go to Diagnostic Trouble Code (DTC) List - Vehicle in Vehicle DTC InformationSystem OK
IMPORTANT
The throttle angle and pedal angle may not correspond during this procedure.
IMPORTANT
The test lamp may momentarily flash when testing these circuits. This is considered normal.
IMPORTANT
The test lamp may momentarily flash when testing these circuits. This is considered normal.

DTC P2176