Diagnostic Test

CHECK FOR AN ACTIVE DTC
NOTE:
Inspect and test the Battery with the Midtronics Battery Tester or equivalent for a shorted or dead cell before continuing with this test.

NOTE:
The Alternator belt and tensioner condition must be checked before continuing.
1. Start the engine.
2. Allow the idle to stabilize.
3. With the scan tool, read DTCs and record on the repair order.
  generator
  
  Is the DTC active or pending?
  
  Yes
  - Go To 2
  No
  - Perform the INTERMITTENT CONDITION diagnostic procedure. Refer to INTERMITTENT CONDITION .
CHECK THE (A804) ALTERNATOR SENSE CIRCUIT FOR AN OPEN/HIGH RESISTANCE
1. Turn the ignition off.
2. Disconnect the Alternator 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 (A804) Alternator Sense circuit between the Alternator harness connector and the GPEC Adaptor.
  Is the resistance below 3.0 Ohms?
  
  Yes
  - Go To 3
  No
  - Repair the (A804) Alternator Sense circuit for an open or high resistance.
  - Perform the POWERTRAIN VERIFICATION TEST. Refer to POWERTRAIN VERIFICATION TEST .
CHECK THE (A804) ALTERNATOR SENSE CIRCUIT FOR A SHORT TO GROUND
1. Check for continuity between ground and the (A804) Alternator Sense circuit at the Alternator harness connector.
  Is there continuity between ground and the (A804) Alternator Sense circuit?
  
  Yes
  - Repair the (A804) Alternator Sense circuit for a short to ground.
  - Perform the POWERTRAIN VERIFICATION TEST. Refer to POWERTRAIN VERIFICATION TEST .
  No
  - Go To 4
ALTERNATOR OPERATION
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.
1. Reconnect the Alternator harness connector.
2. Reconnect the PCM C2 harness connector with the GPEC Adaptor still connected in line.
3. Start the engine.
4. Measure the voltage at the Alternator Output stud.
5. Probe and measure the voltage of the (A804) Alternator Sense circuit at the GPEC Adaptor.
  NOTE:
  The Alternator Sense circuit reading will normally be approximately 3.5 volts less than the voltage at the Alternator Output terminal due to an internal resistor inside the Alternator.
  
  Does the voltage read as described above?
  
  Yes
  - Go To 5
  No
  - Verify that there is good pin to terminal contact in the Alternator and Powertrain Control Module connectors. Replace the Alternator if no problems were found with the connectors. Refer to GENERATOR, REMOVAL AND INSTALLATION .
  - Perform the POWERTRAIN VERIFICATION TEST. Refer to POWERTRAIN VERIFICATION TEST .
CHECK RELATED PCM AND COMPONENT CONNECTIONS
1. Perform the NO RESPONSE FROM THE PCM test procedure and check the PCM powers and grounds. Refer to DIAGNOSIS AND TESTING .
2. Perform any Service Bulletins that apply.
3. Disconnect all PCM harness connectors.
4. Disconnect all related in-line harness connections (if equipped).
5. Disconnect the related component harness connectors.
6. Inspect harness connectors, component connectors, and all male and female terminals for the following conditions:
  - Proper connector installation.
  - Damaged connector locks.
  - Corrosion.
  - Other signs of water intrusion.
  - Weather seal damage (if equipped).
  - Bent terminals.
  - Overheating due to a poor connection (terminal may be discolored due to excessive current draw).
  - Terminals that have been pushed back into the connector cavity.
  - Check for spread terminals and verify proper terminal tension.
  Repair any conditions that are found.
7. Reconnect all PCM harness connectors. Be certain that all harness connectors are fully seated and the connector locks are fully engaged.
8. Reconnect all in-line harness connectors (if equipped). Be certain that all connectors are fully seated and the connector locks are fully engaged.
9. Reconnect all related component harness connectors. Be certain that all connectors are fully seated and the connector locks are fully engaged.
10. With the scan tool, erase DTCs.
11. Test drive or operate the vehicle in accordance with the when monitored and set conditions.
12. With the scan tool, read DTCs.
  Did the DTC return?
  
  Yes
  - Replace the Powertrain Control Module in accordance with the Service information. Refer to MODULE, POWERTRAIN CONTROL (PCM), REMOVAL AND INSTALLATION .
  - Perform the POWERTRAIN VERIFICATION TEST. Refer to POWERTRAIN VERIFICATION TEST .
  No
  - Perform the POWERTRAIN VERIFICATION TEST. Refer to POWERTRAIN VERIFICATION TEST .
  - Test complete.