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Home >> Cadillac >> 2006 >> STS Base, 3.6 7, RWD >> Repair and Diagnosis >> External Pages >> Different variant/trim >> Section 13 (Engine Control System - 4.6L (LH2) - DTC P0420 To P0689) >> DTC P0687 >> Test Description

Test Description

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

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

  1. 2:  The engine will crank but will not run with a short to battery positive voltage, or a short to the ignition 1 voltage on the powertrain relay coil control circuit.
DTC P0687

Step Action Values Yes No
Schematic Reference:  Engine Controls Schematics 
Connector End View Reference: Engine Control Module Connector End Views and 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. Observe the Freeze Frame/Failure Records for this DTC.
  2. Turn OFF the ignition for 30 seconds.
  3. Turn ON the ignition, with the engine OFF.
  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 3  Go to Intermittent Conditions
3
  1. Turn OFF the ignition.
  2. Remove the powertrain relay from the underhood fuse block with the J 43244  Relay Puller Pliers. Refer to Relay Replacement (Within an Electrical Center) or Relay Replacement (Attached to Wire Harness) .
    3. NOTE: Refer to Test Probe Notice .
  3. Probe the powertrain relay coil control circuit terminal at the underhood fuse block, with a test lamp that is connected to a good ground. Refer to Troubleshooting with a Test Lamp .
Does the test lamp illuminate?		 - Go to Step 7  Go to Step 4 
4
  1. Turn ON the ignition, with the engine OFF.
  2. Probe the powertrain relay coil control circuit terminal at the underhood fuse block with a test lamp that is connected to a good ground.
Does the test lamp illuminate?		 - Go to Step 5  Go to Step 9 
5
  1. Turn OFF the ignition.
  2. Disconnect the engine control module (ECM) electrical connector that contains the powertrain relay coil control circuit. Refer to Engine Control Module Replacement .
  3. Turn ON the ignition, with the engine OFF.
    4. NOTE: Refer to Test Probe Notice .
  4. Probe the powertrain relay coil control circuit at the underhood fuse block with a test lamp that is connected to a good ground.
Does the test lamp illuminate?		 - Go to Step 6  Go to Step 13 
6
  1. Turn OFF the ignition.
  2. Disconnect the negative battery cable at the battery. Refer to Battery Negative Cable Disconnection and Connection .
  3. Disconnect the underhood fuse block electrical connector that contains the powertrain relay coil control circuit. Refer to Underhood Electrical Center or Junction Block Replacement .
  4. Disconnect the powertrain relay coil control circuit terminal from the underhood fuse block electrical connector. Refer to Delphi Connectors (Micro .64) or Delphi Connectors (Micro-Pack 100W) or Delphi Connectors (Pull To Seat) or Delphi Connectors (Push To Seat) or Delphi Connectors (Weather Pack) or Delphi Connectors (12-Way) .
  5. Connect the electrical connector that contained the powertrain relay coil control circuit to the underhood fuse block.
  6. Connect the negative battery cable at the battery.
  7. Turn ON the ignition, with the engine OFF.
  8. Probe the powertrain relay coil control circuit terminal at the electrical connector for the underhood fuse block with a test lamp that is connected to good ground.
Does the test lamp illuminate?		 - Go to Step 14  Go to Step 17 
7
  1. Turn OFF the ignition.
  2. Disconnect the ECM electrical connector that contains the powertrain relay coil control circuit. Refer to Engine Control Module Replacement .
    3. NOTE: Refer to Test Probe Notice .
  3. Probe the powertrain relay coil control circuit at the underhood fuse block with a test lamp that is connected to a good ground.
Does the test lamp illuminate?		 - Go to Step 8  Go to Step 13 
8
  1. Turn OFF the ignition.
  2. Disconnect the negative battery cable at the battery. Refer to Battery Negative Cable Disconnection and Connection .
  3. Disconnect the underhood fuse block electrical connector that contains the powertrain relay coil control circuit. Refer to Underhood Electrical Center or Junction Block Replacement .
  4. Connect the negative battery cable at the battery.
  5. Probe the powertrain relay coil control circuit terminal at the underhood fuse block electrical connector with a test lamp that is connected to a good ground.
Does the test lamp illuminate?		 - Go to Step 14  Go to Step 17 
9 Measure the resistance from terminal #30 of the powertrain relay to terminal #87 with a DMM.
Does the DMM display the specified value?		 infinity ohm Go to Step 10  Go to Step 15 
10 Measure the resistance from terminal #30 of the powertrain relay to terminal #86 with a DMM.
Does the DMM display the specified value?		 infinity ohm Go to Step 11  Go to Step 15 
11 Measure the resistance from terminal #85 of the powertrain relay to terminal #87 with a DMM.
Does the DMM display the specified value?		 infinity ohm Go to Step 12  Go to Step 15 
12 Test for an intermittent and for a poor connection at the powertrain relay location of the underhood fuse block. Refer to Testing for Intermittent Conditions and Poor Connections .
Did you find a condition?		 - Go to Step 17  Go to Intermittent Conditions
13 Test for shorted terminals and poor connections at the ECM electrical connectors. Refer to Testing for Intermittent Conditions and Poor Connections and Delphi Connectors (Micro .64) or Delphi Connectors (Micro-Pack 100W) or Delphi Connectors (Pull To Seat) or Delphi Connectors (Push To Seat) or Delphi Connectors (Weather Pack) or Delphi Connectors (12-Way) .
Did you find and correct the condition?		 - Go to Step 18  Go to Step 16 
14 Repair the short to voltage in the powertrain relay coil control circuit between the underhood fuse block electrical connector and the ECM electrical connector. Refer to Wiring Repairs .
Did you complete the repair?		 - Go to Step 18  -
15 Replace the powertrain relay. Refer to Relay Replacement (Within an Electrical Center) or Relay Replacement (Attached to Wire Harness) .
Did you complete the replacement?		 - Go to Step 18  -
16 Replace the ECM. Refer to Control Module References for replacement, setup, and programming.
Did you complete the replacement?		 - Go to Step 18  -
17 Replace the underhood fuse block. Refer to Underhood Electrical Center or Junction Block Replacement .
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. Turn ON the ignition, with the engine OFF.
  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 3  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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