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Home >> Mercury >> 2008 >> Milan Base, 3.0 1, FWD >> Repair and Diagnosis >> External Pages >> Different car >> Section 1680 (Charging System - General Information) >> Diagnostic Tests >> Charging System >> Pinpoint Tests >> Pinpoint Test C: The Charging System Warning Indicator is On With the Engine Running and No Charging System DTCs Present >> PINPOINT TEST C: THE CHARGING SYSTEM WARNING INDICATOR IS ON WITH THE ENGINE RUNNING AND NO CHARGING SYSTEM DTCs PRESENT

PINPOINT TEST C: THE CHARGING SYSTEM WARNING INDICATOR IS ON WITH THE ENGINE RUNNING AND NO CHARGING SYSTEM DTCs PRESENT

WARNING: This page is about a different car, the 2010 Lincoln Town Car. However, it is still accessible from the selected car via links, so may be relevant.
NOTE: Make sure battery voltage is greater than 12.2 volts prior to carrying out this pinpoint test.
NOTE: Do not have a battery charger attached during vehicle testing.
  1. C1 CHECK THE BATTERY CONDITION 
    • Carry out the Battery - Condition Test to determine if the battery can hold a charge and is OK for use. Refer to BATTERY, MOUNTING & CABLES article.
    • Does the battery pass the condition test? 
    1. YES  : Go to  C2.
    2. NO  : INSTALL a new battery. REFER to BATTERY, MOUNTING & CABLES article. TEST the system for normal operation.
  2. C2 CHECK THE GENERATOR B+ CONNECTION 
    • Key in OFF position.
    • Inspect generator C102b connection. Connection should be tight.
      • Fig 1: Checking Generator B+ Circuit For Voltage
      GF0004524Courtesy of FORD MOTOR CO.
    • Measure the voltage between generator C102b, circuit 38 (RD) and ground.
    • Is generator C102b connection tight and does the generator B+ measure battery voltage? 
    1. YES  : Go to  C3.
    2. NO  : TIGHTEN the generator B+ connection or REPAIR the circuit. CLEAR the any DTCs. REPEAT the self-test. TEST the system for normal operation.
  3. C3 CHECK THE VOLTAGE DROP IN THE B+ circuit 38 (RD) 
      Fig 2: Checking B+ Circuit
      GF0014500Courtesy of FORD MOTOR CO.
    • With the engine running, measure the voltage drop between generator B+ C102b, circuit 38 (RD) and the positive battery terminal.
    • Is the voltage drop less than 0.5 volt? 
    1. YES  : Go to  C4.
    2. NO  : CHECK for any corrosion in the B+ C102b, circuit 38 (RD), positive battery cable and/or connections. REPAIR as necessary. TEST the system for normal operation.
  4. C4 CHECK THE DTCs IN THE PCM 
    • Key in OFF position.
    • Connect the diagnostic tool.
    • Key in START position.
    • Enter the following diagnostic mode on the diagnostic tool: Retrieve PCM DTCs
    • Use the recorded PCM DTCs from the continuous and on-demand self tests.
    • Are any PCM DTCs recorded? 
    1. YES  : For all DTCs EXCEPT charging system DTCs, REFER to the Introduction - Gasoline Engines article. If any charging system DTCs are present, go to Pinpoint Test B . If referred here by the Introduction - Gasoline Engines article, go to  C5.
    2. NO  : Go to  C5.
  5. C5 MONITOR PID GENFIL 
    • With the engine running, monitor PID GENFIL.
    • Does PID GENFIL show fault? 
    1. YES  : Go to  C6.
    2. NO  : REPAIR/INSTALL a new IC, IC-to-PCM connection or the PCM. TEST the system for normal operation.
  6. C6 MONITOR PID VPWR 
    • With the engine running, monitor PID VPWR.
    • Is PID VPWR greater than 15.6 volts? 
    1. YES  : Go to  C7.
    2. NO  : Go to  C8.
  7. C7 CHECK PCM VPWR PID 
      Fig 3: Checking Charging System Voltage
      GF0001354Courtesy of FORD MOTOR CO.
    • With the engine running, measure the battery voltage.
    • Monitor the VPWR PID.
    • Is battery voltage and VPWR PID within 0.6 volt of each other? 
    1. YES  : Go to  C8.
    2. NO  : Go to  C9.
  8. C8 MEASURE PCM INPUT VOLTAGE 
    • Key in OFF position.
    • Disconnect: PCM C175b
    • Key in ON position.
      • Fig 4: Checking Circuit For Voltage
      GF0016081Courtesy of FORD MOTOR CO.
    • Measure the voltage between PCM input voltage pins 35, 36 and 45 to PCM ground pin 10.
    • Are voltages within 0.5 volt of PID VPWR? 
    1. YES  : INSTALL a new PCM.
    2. NO  : REPAIR high resistance or loose connections between C175b-35 circuit 361 (RD), C175b-36 circuit 361 (RD), C175b-45 circuit 729 (RD/WH) PCM power circuits or C175b-10, circuit 57 (BK), PCM ground circuit.
  9. C9 MONITOR THE PCM PID GENMON WITH KEY ON/ENGINE RUNNING (KOER) 
    • Key in START position.
    • With the engine at idle, wait 15 seconds for the GENVDSD PID to increase to greater than 13 volts.
    • Monitor PID GENMON at idle and 3,000 RPM.
    • Does the GENMON PID read between 3% and 98% at engine idle speed and at 3,000 RPM? 
    1. YES  : Go to  C10.
    2. NO  : Go to  C11.
  10. C10 MONITOR PID GENVDSD 
    • With the engine running, monitor PID GENVDSD.
    • Is PID GENVDSD greater than 15.2 volts? 
    1. YES  : REPAIR connection on circuit 35 (OG/LB). INSPECT generator C102a-3 for damage. CLEAR the DTCs. REPEAT the self-test. TEST the system for normal operation. If no problems are found, INSTALL a new generator. REFER to GENERATOR & REGULATOR article. TEST the system for normal operation.
    2. NO  : REFLASH or INSTALL a new PCM.
  11. C11 CHECK FOR SHORTED CIRCUITS 
    • Key in OFF position.
    • Disconnect: Generator C102a
    • Key in ON position.
    • Verify that PID GENMON reads 100%.
    • Carry out the Wiggle Test of wiring to determine if PID GENMON changes from 100%.
    • Does PID GENMON change from 100%? 
    1. YES  : REPAIR short circuit on C102a-1 1817 (YE).
    2. NO  : Go to  C12.
  12. C12 CHECK THE PCM PID GENMON INPUT TO THE PCM 
      Fig 5: Connecting Fused Jumper Wire
      GF0016079Courtesy of FORD MOTOR CO.
    • Connect a fused (10A) jumper wire between generator C102a-1, circuit 1817 (YE), harness side and ground.
    • Key in ON position.
    • Monitor the GENMON PID while carrying out a Wiggle Test on the wire harness.
    • Does the GENMON PID read 0%? 
    1. YES  : REPAIR open connection on circuit 1817 (YE) C102a-1, and PCM C175e-26. CLEAR the DTCs. REPEAT the self-test. TEST the system for normal operation.
    2. NO  : INSTALL a new generator. REFER to GENERATOR & REGULATOR article. CLEAR the DTCs. REPEAT the self-test. TEST the system for normal operation.
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