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Home >> Chevrolet >> 2004 >> Optra Base, Standard >> Repair and Diagnosis >> Engine Performance >> System >> Engine Controls - 1.4L DOHC - DTC P1402 To DTC P1661 >> DTC P1661 >> Test Description
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Test Description

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

  1. 5:  This step tests the control circuit for a shorted to ground.
  2. 8:  This step tests the control circuit for an open.
Step Action Values Yes No
Schematic Reference:  Engine Controls Schematics 
Connect End View Reference:  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. Clear the DTC with a scan tool.
  3. Wait 30 seconds.
Does DTC P1661 set?		 - Go to Step 3  Go to Step 4 
3 Is DTC P0656 set? - Go to Step 15  Go to Step 5 
4
  1. Turn OFF the ignition for 30 seconds.
  2. Operate the vehicle within the Conditions for Running the DTC.
Did the DTC fail this ignition?		 - Go to Step 5  Go to Intermittent Conditions
5 
  1. Turn OFF the ignition.
  2. Disconnect the engine control module (ECM).
  3. Turn ON the ignition, with the engine OFF.
Does the MIL illuminate?		 - Go to Step 14  Go to Step 6 
6
  1. Turn OFF the ignition.
  2. Connect a 3-ampere fuse jumper wire from the control circuit of the MIL at the ECM harness connector terminal to a good ground.
  3. Turn ON the ignition, with the engine OFF.
Does the MIL illuminate?		 - Go to Step 13  Go to Step 7 
7
  1. Turn OFF the ignition.
  2. Remove the IPC. Refer to Instrument Cluster Replacement in Instrument Panel, Gauges and Console.
  3. Turn ON the ignition, with the engine OFF.
  4. Probe the ignition 1 voltage circuit of the MIL with a test lamp connected to a good ground.
Does the test lamp illuminate?		 - Go to Step 8  Go to Step 15 
8 
  1. Connect a 3-ampere fuse jumper wire from the control circuit of the MIL at the ECM harness connector terminal to a good ground.
  2. Probe the control circuit of the MIL at the IPC harness connector with a test lamp connected to battery positive voltage.
Does the test lamp illuminate?		 - Go to Step 9  Go to Step 14 
9
  1. Turn OFF the ignition.
  2. Disconnect the CLUSTER fuse in the Instrument Panel (I/P) Fuse Block.
  3. Measure the resistance of the ignition 1 voltage circuit of the MIL from the fuse terminal to the IPC harness connector terminal.
Is the resistance less than the specified value?		 3 Ω Go to Step 10  Go to Step 14 
10 Measure the resistance of the control circuit of the MIL from the ECM harness connector terminal to the IPC harness connector terminal.
Is the resistance less than the specified value?		 3 Ω Go to Step 11  Go to Step 14 
11
  1. Remove the MIL lamp from the cluster. Refer to Instrument Cluster Replacement in Instrument Panel, Gauges and Console.
  2. Measure the resistance of the lamp
Is the resistance within the specified range?		 10-18 Ω Go to Step 12  Go to Step 16 
12 Test for shorted terminals and poor connections at the IPC. Refer to Testing for Intermittent Conditions and Poor Connections and Repairing Connector Terminals in Wiring Systems.
Did you find and correct the condition?		 - Go to Step 19  Go to Step 17 
13 Test for shorted terminals and poor connections at the engine control module (ECM). Refer to Testing for Intermittent Conditions and Poor Connections and Repairing Connector Terminals in Wiring Systems.
Did you find and correct the condition?		 - Go to Step 19  Go to Step 18 
14 Repair the control circuit of the MIL for one of the following conditions:
  • An open
  • A short to ground
  • High resistance

Refer to Wiring Repairs in Wiring Systems.
Did you complete the repair?		 - Go to Step 19  -
15 Repair the ignition 1 voltage circuit of the MIL for one of the following conditions:
  • An open
  • A short to ground
  • High resistance

Refer to Wiring Repairs in Wiring Systems.
Did you complete the repair?		 - Go to Step 19  -
16 Replace the MIL lamp. Refer to Instrument Cluster Bulb Replacement in Instrument Panel, Gauges and Console.
Did you complete the replacement?		 - Go to Step 19  -
17 Replace the IPC. Refer to Instrument Cluster Replacement in Instrument Panel, Gauges and Console.
Did you complete the replacement?		 - Go to Step 19  -
18 Replace the ECM. Refer to Engine Control Module Replacement .
Did you complete the replacement?		 - Go to Step 19  -
19
  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.
Did the DTC fail this ignition?		 - Go to Step 2  Go to Step 20 
20 Are there any DTCs that have not been diagnosed? - Go to Diagnostic Trouble Code (DTC) List System OK
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