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Home >> Cadillac >> 2006 >> Escalade EXT >> Repair and Diagnosis >> Engine Performance >> System >> Engine Control System - 4.8L, 5.3L, And 6.0L - DTC P2121 To DTC U0107 >> DTC P2135 >> Test Description
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Test Description

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

  1. 21:  When the TAC module detects a condition within the TAC system, more than one TAC 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. Disconnecting components during testing may set additional DTCs. Remember this if you review the stored information in Capture Info.
DTC P2135

Step Action Yes No
Schematic Reference: Engine Controls Schematics
Connector End View Reference: Engine Controls Connector End Views or Powertrain Control Module (PCM) Connector End Views
1 Did you perform the Diagnostic System Check - Vehicle? Go to Step 2  Go to Diagnostic System Check - Vehicle
2 Is DTC U0107 set? Go to DTC U0107  Go to Step 3 
3
  1. Turn ON the ignition, with the engine OFF.
  2. Observe the throttle position (TP) sensor 1 and 2 Agree/Disagree parameter with a scan tool.
Does the scan tool TP sensor 1 and 2 Agree/Disagree parameter indicate Disagree?		 Go to Step 5  Go to Step 4 
4
  1. Remove the air inlet duct from the throttle body.
  2. Disconnect the throttle body harness connector.
  3. Connect the jumper wires between the TP sensor terminals of the throttle body harness connector and the corresponding TP sensor terminals of the throttle body.
  4. Observe the TP sensor 1 and 2 with a scan tool.
  5. Slowly open the throttle blade to wide open throttle (WOT) and back to the closed throttle position several times by hand.
Does the TP sensor Agree/Disagree parameter change from Agree to Disagree during the above test?		 Go to Step 18  Go to Diagnostic Aids
5
  1. Disconnect the TP sensor harness connector.
  2. Disconnect the throttle actuator control (TAC) module harness connectors.
  3. Test the TP sensor 1 5-volt reference circuit for resistance with a DMM. Refer to Circuit Testing and Wiring Repairs .
Did you find and correct the condition?		 Go to Step 20  Go to Step 6 
6 Test for a short between the TP sensor 1 5-volt reference circuit and all other TAC module circuits with a DMM. Refer to Circuit Testing and Wiring Repairs .
Did you find and correct the condition?		 Go to Step 20  Go to Step 7 
7 Test the TP sensor 1 signal circuit for resistance with a DMM. Refer to Circuit Testing and Wiring Repairs .
Did you find and correct the condition?		 Go to Step 20  Go to Step 8 
8 Test for a short between the TP sensor 1 signal circuit and all other TAC module circuits with a DMM. Refer to Circuit Testing and Wiring Repairs .
Did you find and correct the condition?		 Go to Step 20  Go to Step 9 
9 Test the TP sensor 1 low reference circuit for resistance with a DMM. Refer to Circuit Testing and Wiring Repairs .
Did you find and correct the condition?		 Go to Step 20  Go to Step 10 
10 Test for a short between the TP sensor 1 low reference circuit and all other TAC module circuits with a DMM. Refer to Circuit Testing and Wiring Repairs .
Did you find and correct the condition?		 Go to Step 20  Go to Step 11 
11 Test the TP sensor 2 5-volt reference circuit for resistance with a DMM. Refer to Circuit Testing and Wiring Repairs .
Did you find and correct the condition?		 Go to Step 20  Go to Step 12 
12 Test for a short between the TP sensor 2 5-volt reference circuit and all other TAC module circuits with a DMM. Refer to Circuit Testing and Wiring Repairs .
Did you find and correct the condition?		 Go to Step 20  Go to Step 13 
13 Test the TP sensor 2 signal circuit for resistance with a DMM. Refer to Circuit Testing and Wiring Repairs .
Did you find and correct the condition?		 Go to Step 20  Go to Step 14 
14 Test for a short between the TP sensor 2 signal circuit and all other TAC module circuits with a DMM. Refer to Circuit Testing and Wiring Repairs .
Did you find and correct the condition?		 Go to Step 20  Go to Step 15 
15 Test the TP sensor 2 low reference circuit for resistance with a DMM. Refer to Circuit Testing and Wiring Repairs .
Did you find and correct the condition?		 Go to Step 20  Go to Step 16 
16 Test for a short between the TP sensor 2 low reference circuit and all other TAC module circuits with a DMM. Refer to Circuit Testing and Wiring Repairs .
Did you find and correct the condition?		 Go to Step 20  Go to Step 17 
17 Inspect for an intermittent and for a poor connection at the harness connector of the TAC module. Refer to Testing for Intermittent Conditions and Poor Connections and Repairing Connector Terminals .
Did you find and correct the condition?		 Go to Step 20  Go to Step 18 
18 Inspect for an intermittent and for a poor connection at the harness connector of the throttle body. Refer to Testing for Intermittent Conditions and Poor Connections and Repairing Connector Terminals .
Did you find and correct the condition?		 Go to Step 20  Go to Step 19 
19 Replace the throttle body assembly. Refer to Throttle Body Assembly Replacement .
Did you complete the replacement?		 Go to Step 20  -
20
  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 21 
21  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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