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Home >> Cadillac >> 2006 >> STS Base, 3.6 7, AWD >> Repair and Diagnosis >> Engine Performance >> System >> Engine Control System - 3.6L - DTC P0342 To P0690 >> DTC P0453 >> Test Description
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Test Description

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

  1. 2:  This step verifies that the condition is present.
  2. 4:  This step tests the EVAP atmospheric vent for a restriction. Inspect the vent for a restriction if the FTP voltage drops after removing the fuel fill cap.
  3. 7:  This step tests for high resistance in the low reference circuit of the FTP sensor. The ECM must be completely powered down to obtain an accurate resistance reading. It may take up to 30 minutes for the ECM to power down after the ignition key is removed. Removal of the ECM/TCM fuse allows the ECM to power down completely.
  4. 8:  This step tests the low reference circuit for a short to voltage. A short to voltage on the low reference circuit will damage the ECM. Repair the short to voltage before replacing the ECM, if the voltage on the low reference circuit is more than the specified value.
DTC P0453

Step Action Values Yes No
Schematic Reference: Engine Controls Schematics
Connector End View Reference: Engine Control Module Connector End Views or Engine Controls Connector End Views
1 Did you perform the Diagnostic System Check - Vehicle? - Go to Step 2  Go to Diagnostic System Check - Vehicle
2 
  1. Turn ON the ignition, with the engine OFF.
  2. Observe the fuel tank pressure (FTP) sensor voltage parameter with a scan tool.
Is the voltage less than the specified value?		 4.5 V Go to Step 3  Go to Step 4 
3
  1. Observe the Freeze Frame/Failure Records for this DTC.
  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 4  Go to Diagnostic Aids
4 
  1. Remove the fuel tank cap from the fuel fill pipe.
  2. Observe the FTP sensor voltage parameter with a scan tool.
Is the voltage more than the specified value?		 4.5 V Go to Step 5  Go to Step 15 
5
  1. Turn OFF the ignition.
  2. Raise the vehicle. Refer to Lifting and Jacking the Vehicle .
  3. Disconnect the FTP sensor connector at the evaporative emission (EVAP) canister.
  4. Turn ON the ignition, with the engine OFF.
  5. Observe the FTP sensor voltage parameter with a scan tool.
Is the voltage less than the specified value?		 0.1 V Go to Step 6  Go to Step 9 
6 Measure the voltage between the 5-volt reference circuit of the FTP sensor and a good ground, with a DMM.
Is the voltage less than the specified value?		 6 V Go to Step 8  Go to Step 11 
7 
NOTE: Do NOT use a test lamp to test the continuity of the circuit. Damage to the control module may occur due to excessive current draw.
  1. Turn OFF the ignition.
  2. Remove the ECM/TCM fuse from the underhood fuse block.
  3. Measure the resistance from the low reference circuit of the FTP sensor to a good ground with a DMM.
Is the resistance more than the specified value?		 5 ohm Go to Step 8  Go to Step 12 
8 
  1. Install the ECM/TCM fuse into the underhood electrical center.
  2. Turn ON the ignition, with the engine OFF.
  3. Measure the voltage between the low reference circuit of the FTP sensor and a good ground with a DMM. Refer to Circuit Testing .
Is the voltage less than the specified value?		 1 V Go to Step 10  Go to Step 14 
9 Test the signal circuit of the FTP sensor for a short to voltage. Refer to Circuit Testing and Wiring Repairs .
Did you find and correct the condition?		 - Go to Step 18  Go to Step 13 
10 Test the low reference circuit of the FTP sensor for an open. Refer to Circuit Testing and Wiring Repairs .
Did you find and correct the condition?		 - Go to Step 18  Go to Step 13 
11
IMPORTANT: The engine control module (ECM) for this engine is not equipped with 5-volt reference DTCs. The 5-volt reference circuits are internally and externally connected at the controller. Other sensors that share the 5-volt reference circuit may also have DTCs set. Disconnecting a sensor on the shared 5-volt reference circuit may isolate a shorted sensor. Review the electrical schematic and diagnose the shared circuits and sensors.
Test the 5-volt reference circuit of the FTP sensor for a short to voltage. Refer to Circuit Testing and Wiring Repairs .Did you find and correct the condition?		 - Go to Step 18  Go to Step 13 
12 Test for shorted terminals and for poor connections at the FTP sensor. Refer to Testing for Intermittent Conditions and Poor Connections and Connector Repairs .
Did you find and correct the condition?		 - Go to Step 18  Go to Step 16 
13 Test for shorted terminals and for poor connections at the ECM. Refer to Testing for Intermittent Conditions and Poor Connections and Connector Repairs .
Did you find and correct the condition?		 - Go to Step 18  Go to Step 17 
14
IMPORTANT: The control module and/or the FTP sensor may be damaged if the circuit is shorted to battery positive voltage.
Repair the short to voltage in the low reference circuit of the FTP sensor. Refer to Wiring Repairs .Did you complete the repair?		 - Go to Step 18  -
15 Repair the restriction in the EVAP canister atmospheric vent pipe.
Did you complete the repair?		 - Go to Step 18  -
16 Replace the FTP sensor. Refer to Fuel Tank Pressure Sensor Replacement .
Did you complete the replacement?		 - Go to Step 18  -
17 Replace the ECM. Refer to Control Module References for replacement, setup, and programming.
Did you complete the replacement?		 - Go to Step 18  -
18
  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 19 
19 Observe the Capture Info with a scan tool.
Are there any DTCs that have not been diagnosed?		 - Go to Diagnostic Trouble Code (DTC) List - Vehicle System OK
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