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Home >> GMC >> 2005 >> Sierra 1500 HD, RWD >> Repair and Diagnosis >> External Pages >> Different car >> Section 213 (Automatic Transmission - 5L40-E/5L50-E - (DTC P0757 To DTC P1833)) >> DTC P1825 >> Test Description

Test Description

WARNING: This page is about a different car, the 2005 Cadillac STS. However, it is still accessible from the selected car via links, so may be relevant.

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

  1. 3:  This step tests the transmission manual shift shaft switch assembly for an open ground circuit.
  2. 5:  This step tests for correct reference voltage from the TCM.
DTC P1825

Step Action Value(s) Yes No
1 Did you perform the Diagnostic System Check - Vehicle? - Go to Step 2  Go to Diagnostic System Check - Vehicle in Vehicle DTC Information
2
  1. Install a scan tool.
  2. Turn ON the ignition, with the engine OFF.
    3. IMPORTANT:
    • Before clearing the DTC, use the scan tool in order to record the ECM Freeze Frame and the TCM Failure Records. Using the Clear Info function erases the Freeze Frame and Failure Records from the ECM and the TCM.
    • Using the Clear Info function erases stored DTCs in both the ECM and TCM.
  3. Record the DTC Freeze Frame and Failure Records.
  4. Clear the DTC.
  5. Select Transmission Data on the scan tool.
  6. Select IMS range on the scan tool.
  7. Place the gear select lever in each transmission range: P, R, N, D5, D4, D3, and D2.
Does each range selected match the scan tool IMS range display?		 - Go to Intermittent Conditions in Engine Controls - 3.6L or Intermittent Conditions in Engine Controls - 4.6L Go to Step 3 
3 
  1. Select IMS A/B/C/P on the scan tool.
  2. Place the gear select lever in each transmission range: P, R, N, D5, D4, D3, and D2.
Does the IMS A/B/C/P display match the specified value for each range selected?		 HI/HI/HI/HI Go to Step 13  Go to Step 4 
4
  1. Turn OFF the ignition.
  2. Disconnect the AT inline 20-way connector. Additional DTCs may set.
  3. Turn ON the ignition, with the engine OFF.
Does the scan tool IMS A/B/C/P display indicate HI for all range states?		 - Go to Step 5  Go to Step 9 
5 
  1. Turn OFF the ignition.
  2. Install the J 45681  jumper harness on the TCM side of the AT inline 20-way connector. See Special Tools .
  3. Turn ON the ignition, with the engine OFF.
  4. Using the DMM and the J 35616  GM terminal test kit, measure the voltage at the Transmission Range (TR) signal A circuit of the J 45681  . See Special Tools .

    Refer to Automatic Transmission Inline 20-Way Connector End View (5L40-E) or Automatic Transmission Inline 20-Way Connector End View (5L50-E) .

  5. Measure the voltage at the TR signal B circuit of the J 45681  . See Special Tools .
  6. Measure the voltage at the TR signal C circuit of the J 45681  . See Special Tools .
  7. Measure the voltage at the TR signal P circuit of the J 45681  . See Special Tools .
Did you measure ignition voltage at all four terminals?		 - Go to Step 6  Go to Step 10 
6 Install a fused jumper wire from the TR signal A circuit of the J 45681  to ground while monitoring the scan tool IMS A/B/C/P display. See Special Tools . Refer to Using Fused Jumper Wires in Wiring Systems.
Refer to Automatic Transmission Inline 20-Way Connector End View (5L40-E) or Automatic Transmission Inline 20-Way Connector End View (5L50-E) .
When the TR signal A circuit is grounded, do any other circuits indicate LOW?		 - Go to Step 11  Go to Step 7 
7 Install a fused jumper wire from the TR signal B circuit of the J 45681  to ground while monitoring the scan tool IMS A/B/C/P display. See Special Tools . Refer to Using Fused Jumper Wires in Wiring Systems.
Refer to Automatic Transmission Inline 20-Way Connector End View (5L40-E) or Automatic Transmission Inline 20-Way Connector End View (5L50-E) .
When the TR signal B circuit is grounded, do any other circuits indicate LOW?		 - Go to Step 11  Go to Step 8 
8 Install a fused jumper wire from the TR signal C circuit of the J 45681  to ground while monitoring the scan tool IMS A/B/C/P display. See Special Tools . Refer to Using Fused Jumper Wires in Wiring Systems.
Refer to Automatic Transmission Inline 20-Way Connector End View (5L40-E) or Automatic Transmission Inline 20-Way Connector End View (5L50-E) .
When the TR signal C circuit is grounded, do any other circuits indicate LOW?		 - Go to Step 11  Go to Step 12 
9 Test the TR signal circuits of the switch that did not indicate HI for a short to ground between the TCM connector and the AT inline 20-way connector.
Refer to Testing for Short to Ground and Wiring Repairs in Wiring Systems.
Did you find and correct the condition?		 - Go to Step 18  Go to Step 17 
10 Test TR signal circuits of the switch that did not indicate ignition voltage for an open between the TCM connector and the AT inline 20-way connector.
Refer to Testing for Continuity and Wiring Repairs in Wiring Systems.
Did you find and correct the condition?		 - Go to Step 18  Go to Step 17 
11 Test the affected TR signal circuits for a shorted together condition between the TCM connector and the AT inline 20-way connector.
Refer to Circuit Testing and Wiring Repairs in Wiring Systems.
Did you find and correct the condition?		 - Go to Step 18  Go to Step 17 
12 Test the TR signal circuits of the transmission manual shift shaft switch assembly for an open or shorted condition between the AT inline 20-way connector and the switch.
Refer to Testing for Continuity in Wiring Systems.
Did you find a condition?		 - Go to Step 15  Go to Step 16 
13 Test the ground circuit of the transmission manual shift shaft switch assembly for an open between the AT inline 20-way connector and the chassis ground.
Refer to Testing for Continuity and Wiring Repairs in Wiring Systems.
Did you find and correct the condition?		 - Go to Step 18  Go to Step 14 
14 Test the ground circuit of the transmission manual shift shaft switch assembly for an open between the AT inline 20-way connector and the switch.
Refer to Testing for Continuity in Wiring Systems.
Did you find a condition?		 - Go to Step 15  Go to Step 16 
15 Replace the automatic transmission wiring harness. Refer to Transmission Internal Electrical Harness Replacement .
Is the action complete?		 - Go to Step 18  -
16 Replace the transmission manual shift shaft switch assembly. Refer to Manual Shaft Shift Position Switch Replacement .
Is the action complete?		 - Go to Step 18  -
17 Replace the TCM. Refer to Control Module References in Computer/Integrating Systems for replacement, setup, and programming.
Is the action complete?		 - Go to Step 18  -
18 Perform the following procedure in order to verify the repair:
  1. Select DTC.
  2. Select Clear Info.
  3. Turn ON the ignition, with the engine OFF.
  4. The transmission manual shift shaft switch assembly must indicate a valid range for 5 seconds.
  5. Select Specific DTC.
  6. Enter DTC P1825.

Has the test run and passed?		 - Go to Step 19  Go to Step 2 
19 With the scan tool, observe the stored information, capture info and DTC info.
Does the scan tool display any DTCs that you have not diagnosed?		 - Go to Diagnostic Trouble Code (DTC) List - Vehicle in Vehicle DTC Information System OK
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