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Home >> Cadillac >> 2004 >> CTS Base, 3.6 7 >> Repair and Diagnosis >> External Pages >> Different variant/trim >> Section 15 (Engine Controls - 2.6L & 3.2L - Diagnosis (DTC P2096 - P2636)) >> Diagnostic Trouble Codes >> DTC P2123 >> Conditions for Clearing the MIL/DTC

Conditions for Clearing the MIL/DTC

WARNING: This page is about a different variant/trim than selected.
DTC P2123

Step Action Values Yes No
Schematic Reference:  Engine Controls Schematics 
Connector End View Reference:  Engine Control Module (ECM) Connector End Views  or  Engine Controls Connector End Views 
1 Did you perform the Diagnostic System Check-Engine Controls? - Go to Step 2  Go to Diagnostic System Check - Engine Controls
2
  1. Turn ON the ignition, with the engine OFF.
  2. Observe the accelerator pedal position (APP) sensor 1 voltage with a scan tool.
Is the APP sensor 1 voltage more than the specified value?
4.8 V Go to Step 3  Go to Step 4 
3
  1. Turn OFF the ignition.
  2. Disconnect the accelerator pedal position (APP) sensor harness connector.
  3. Turn ON the ignition, with the engine OFF.
  4. Observe the APP sensor 1 voltage with a scan tool.
Is the APP sensor 1 voltage less than the specified value?
0.02 V Go to Step 6  Go to Step 13 
4
  1. Observe the Freeze Frame/Failure Records for this DTC.
  2. Turn OFF the ignition.
  3. Start the engine.
  4. 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 6  Go to Step 5 
5
  1. Observe the DTC information with a scan tool.
  2. Slowly depress the accelerator pedal to wide open throttle (WOT), then slowly return the accelerator pedal to the closed position.
  3. Repeat this action several times.
Did the DTC fail this ignition?
- Go to Step 19  Go to Intermittent Conditions
6
  1. Turn OFF the ignition.
  2. Disconnect the APP sensor harness connector.
  3. Turn ON the ignition, with the engine OFF.
  4. Measure the voltage from the 5-volt reference circuit of the APP sensor 1 to a good ground with a DMM.
Is the voltage within the specified range?
4.8-5.2 V Go to Step 7  Go to Step 11 
7
  1. Turn OFF the ignition.
  2. Connect a 3-amp fused jumper wire between the 5-volt reference circuit of the APP sensor 1 and the signal circuit of the APP sensor 2.
  3. Turn ON the ignition, with the engine OFF.
  4. Observe the APP sensor 1 voltage with the scan tool.
Is the APP sensor 1 voltage within the specified range?
4.8-5.2 V Go to Step 8  Go to Step 13 
8
  1. Turn OFF the ignition.
  2. IMPORTANT: It may be necessary to remove the ECM/TCM fuse to allow the ECM to power down.
  3. Allow the engine control module (ECM) to completely power down. This can be verified by the loss of communication with the scan tool.
  4. Measure the resistance from the low reference circuit of the APP sensor 1 to a good ground with a DMM.
Is the resistance less than the specified value?
5 ohm Go to Step 16  Go to Step 9 
9 Test the low reference circuit of the APP sensor 1 for an open or high resistance. Refer to Circuit Testing and Wiring Repairs in Wiring Systems.
Did you find and correct the condition?
- Go to Step 21  Go to Step 10 
10 Measure the resistance from the case of the ECM to the battery ground.
Is the resistance less than the specified value?
5 ohm Go to Step 17  Go to Step 15 
11
  1. Measure the voltage from the 5-volt reference circuit of the APP sensor 1 to a good ground with a DMM.
  2. Observe the DMM as you disconnect all components that share the 5-volt reference voltage source one at a time.
Is the voltage within the specified range after disconnecting any component?
4.8-5.2 V Go to Step 18  Go to Step 12 
12 Test the 5-volt reference circuit of the APP sensor 1 for a short to voltage. Refer to Circuit Testing and Wiring Repairs in Wiring Systems.
Did you find and correct the condition?
- Go to Step 21  Go to Step 14 
13 Test the signal circuit of the APP sensor for a short to voltage. Refer to Circuit Testing and Wiring Repairs in Wiring Systems.
Did you find and correct the condition?
- Go to Step 21  Go to Step 17 
14
  1. Test the 5-volt reference circuits of the following components for a short to voltage:
    • The mass air flow (MAF) sensor
    • The fuel tank pressure (FTP) sensor
  2. Repair as necessary. Refer to Circuit Testing and Wiring Repairs in Wiring Systems.
Did you find and correct the condition?
- Go to Step 21  Go to Step 17 
15 Repair the open or high resistance in the ECM ground circuit. Refer to Wiring Repairs in Wiring Systems.
Did you complete the repair?
- Go to Step 21  -
16 Test for an intermittent and for a poor connection at the APP sensor. 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 21  Go to Step 19 
17 Test for an intermittent and for a poor connection 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 21  Go to Step 20 
18 Replace the component that when disconnected, caused the voltage to return to the specified value. Refer to the appropriate replacement procedure.
Did you complete the replacement?
- Go to Step 21  -
19 Replace the accelerator pedal assembly. Refer to Accelerator Pedal Position (APP) Sensor Replacement .
Did you complete the replacement?
- Go to Step 21  -
20 Replace the ECM. Refer to Engine Control Module (ECM) Replacement .
Did you complete the replacement?
- Go to Step 21  -
21
  1. Clear the DTCs with a scan tool.
  2. Turn OFF the ignition for 30 seconds.
  3. Start the engine.
  4. 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 2  Go to Step 22 
22 Observe the Capture Info with a scan tool.
Are there any DTCs that have not been diagnosed?
- Go to Diagnostic Trouble Code (DTC) List System OK