Diagnostic Test

CHECK FOR AN ACTIVE DTC
NOTE:
Diagnose and repair any Throttle Body circuit, system voltage or 5-Volt Reference DTCs before continuing with this test.
1. Start the engine and allow it to idle.
  WARNING:
  When the engine is operating, do not stand in direct line with the fan. Do not put your hands near the pulleys, belts or fan. Do not wear loose clothing. Failure to follow these instructions may result in possible serious or fatal injury.
2. With the scan tool, read DTCs and record on the repair order.
  NOTE:
  If the DTC does not reset it may be necessary to test drive the vehicle.
  
  Is the DTC active or pending?
  
  Yes
  - Go To 3
  No
  - Go To 2
THROTTLE FOLLOWER TEST
1. Turn the ignition on.
2. With the scan tool, perform the ETC Throttle Follower Test and monitor the TPS 1 or TPS 2 voltage.
3. Slowly press the accelerator pedal down.
4. The voltage for TPS 1 should start at approximately 0.7 volts and increase to approximately 4.3 volts.
  Is the TPS 1 voltage within the range of the listed specification?
  
  Yes
  - Perform the INTERMITTENT CONDITION diagnostic procedure. Refer to INTERMITTENT CONDITION .
  No
  - Go To 3
CHECK THE (K22) TPS 1 SIGNAL CIRCUIT FOR EXCESSIVE RESISTANCE
1. Turn the ignition off.
2. Disconnect the Throttle Body harness connector.
3. Disconnect the PCM C2 harness connector.
  CAUTION:
  Do not probe the PCM harness connectors. Probing the PCM harness connectors will damage the PCM terminals resulting in poor terminal to pin connection. Install the GPEC Diagnostic Adaptor to perform the diagnosis.
4. Connect the (special tool #10436, Adapter, GPEC Diagnostic).
5. Measure the resistance of the (K22) TPS 1 Signal circuit between the Throttle Body harness connector and the GPEC Adaptor.
  Is the resistance below 3.0 Ohms?
  
  Yes
  - Go To 4
  No
  - Repair the excessive resistance in the (K22) TPS 1 Signal circuit.
  - Perform the POWERTRAIN VERIFICATION TEST. Refer to POWERTRAIN VERIFICATION TEST .
CHECK THE (F855) 5-VOLT SUPPLY CIRCUIT FOR EXCESSIVE RESISTANCE
1. Measure the resistance of the (F855) 5-Volt Supply circuit between the Throttle Body harness connector and the GPEC Adaptor.
  Is the resistance below 3.0 Ohms?
  
  Yes
  - Go To 5
  No
  - Repair the excessive resistance in the (F855) 5-Volt Supply circuit.
  - Perform the POWERTRAIN VERIFICATION TEST. Refer to POWERTRAIN VERIFICATION TEST .
CHECK THE (K922) TPS RETURN CIRCUIT FOR EXCESSIVE RESISTANCE
1. Measure the resistance of the (K922) TPS Return circuit between the Throttle Body harness connector and the GPEC Adaptor.
  Is the resistance below 3.0 Ohms?
  
  Yes
  - Go To 6
  No
  - Repair the excessive resistance in the (K922) TPS Return circuit.
  - Perform the POWERTRAIN VERIFICATION TEST. Refer to POWERTRAIN VERIFICATION TEST .
THROTTLE POSITION SENSOR
1. Reconnect the PCM C2 harness connector.
2. Turn the ignition on.
3. With the scan tool, monitor the TPS 1 voltage.
4. Connect a jumper between the (K22) TPS 1 Signal circuit and the (F855) 5-Volt Supply circuit.
  NOTE:
  The TPS 1 voltage should change from approximately 0.0 volts with the connector unplugged to 5.0 volts with the jumper in place.
  
  Is the voltage reading within the listed specification when the jumper is installed?
  
  Yes
  - Verify that there is good pin to terminal contact in the Throttle Body and Powertrain Control Module connectors. If no problems are found, replace the Throttle Body Assembly. Refer to 6.2L . Disconnect the Battery when replacing the Throttle Body Assembly. After installation is complete, use a scan tool and select the ETC RELEARN function.
  - Perform the POWERTRAIN VERIFICATION TEST. Refer to POWERTRAIN VERIFICATION TEST .
  No
  - Go To 7
    NOTE:
    Remove the jumper before continuing.
POWERTRAIN CONTROL MODULE (PCM)
1. Using the wiring diagram/schematic as a guide, inspect the wiring and connectors between the Throttle Body and the Powertrain Control Module (PCM).
2. Look for any chafed, pierced, pinched or partially broken wires.
3. Look for broken, bent, pushed out or corroded terminals. Verify that there is good pin to terminal contact in the Throttle Body and Powertrain Control Module connectors.
4. Perform any y apply.
  Were there any problems found?
  
  Yes
  - Repair as necessary.
  - Perform the POWERTRAIN VERIFICATION TEST. Refer to POWERTRAIN VERIFICATION TEST .
  No
  - Replace and program the Powertrain Control Module in accordance with the Service Information. Refer to MODULE, POWERTRAIN CONTROL (PCM), REMOVAL .
  - Perform the POWERTRAIN VERIFICATION TEST. Refer to POWERTRAIN VERIFICATION TEST .