Pinpoint Test I: The Charging System Warning Indicator is On With the Engine Running and No Charging System DTCs Present
Pinpoint Test
Pinpoint Test I: The Charging System Warning Indicator is On With the Engine Running and No Charging System DTCs Present
Refer to Wiring Diagram Set 12, Charging System for schematic and connector information. Diagrams By Number
Normal Operation
With the engine running, the charging system warning indicator is off. The A circuit SBB17 (RD) from the battery B+ to the generator regulator is 13-15 volts. This voltage feedback is used by the regulator to maintain the battery voltage at the desired setpoint. The S (stator) circuit (internal to the generator) is used to monitor generator operation. This circuit and other regulator internal conditions are checked by the regulator to allow the PCM to turn off the charging system warning indicator by sending a message over the Controller Area Network (CAN) bus to the Instrument Cluster (IC). The positive battery output (B+) circuit SDC14 (RD) is the generator output supplied to the battery and electrical system.
This pinpoint test is intended to diagnose the following:
- Generator
- Circuitry
- IC
- PCM
PINPOINT TEST I: THE CHARGING SYSTEM WARNING INDICATOR IS ON WITH THE ENGINE RUNNING AND NO CHARGING SYSTEM DTCs PRESENT
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.
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I1 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. Pinpoint Tests
- Does the battery pass the condition test?
Yes
GO to I2.
No
INSTALL a new battery. REFER to Battery. TEST the system for normal operation.
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I2 CHECK THE GENERATOR B+ CONNECTION
- Ignition OFF.
- Inspect generator C102b connection. Connection should be tight.
- Measure the voltage between generator C102b, circuit SDC14 (RD) and ground.
- Is generator C102b connection tight and does the generator B+ measure battery voltage?
Yes
GO to I3.
No
TIGHTEN the generator B+ connection or REPAIR the circuit. CLEAR the any DTCs. REPEAT the self-test. TEST the system for normal operation.
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I3 CHECK THE VOLTAGE DROP IN THE B+ CIRCUIT SDC14 (RD)
- With the engine running at idle, headlamps on and blower on high, measure the voltage drop between generator B+ C102b, circuit SDC14 (RD) and the positive battery terminal.
- Is the voltage drop less than 0.5 volt?
Yes
GO to I4.
No
CHECK for resistance in the B+ C102b, circuit SDC14 (RD), positive battery cable and/or connections. REPAIR as necessary. TEST the system for normal operation.
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I4 CHECK THE DTCs IN THE PCM
- Ignition OFF.
- Connect the scan tool.
- Start the engine.
- Enter the following diagnostic mode on the scan tool: Retrieve PCM DTCs.
- Use the recorded PCM DTCs from the continuous and on-demand self tests.
- Are any PCM DTCs recorded?
Yes
For all DTCs EXCEPT charging system DTCs, REFER to the Computers and Control Systems Information. If any charging system DTCs are present, Go To Pinpoint Test B. If referred here by Computers and Control Systems Information, GO to I5. Pinpoint Test B: DTC B1318 and/or B1676
No
GO to I5.
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I5 MONITOR PID GENFIL
- With the engine running, monitor PID GENFIL.
- Does PID GENFIL show fault?
Yes
GO to I6.
No
REFER to Instrument Panel, Gauges and Warning Indicators.
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I6 MONITOR PID VPWR
- With the engine running, monitor PIDS VPWR, GENFIL, GENVDSD.
- Is PID VPWR greater than 15.6 volts?
Yes
GO to I7.
No
GO to I8.
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I7 CHECK PCM VPWR PID
- With the engine running, measure the battery voltage.
- Monitor the VPWR PID.
- Are the battery voltage and VPWR PID within 0.5 volt of each other?
Yes
GO to I8.
No
REPAIR high resistance or loose connections between C175b-51 circuit CBP47 (GN/BU), C175b-52 circuit CBP47 (GN/BU) PCM power circuits or C175b-66, circuit
GD120 (BK/GN), PCM ground circuit.
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I8 MONITOR THE PCM PID GENERATOR MONITOR WITH KOER
- Connect: PCM C175b.
- Start the engine.
- 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?
Yes
GO to I9.
No
GO to I10.
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I9 MONITOR PID GENVDSD
- With the engine running, monitor PID GENVDSD.
- Is PID GENVDSD greater than 15.2 volts?
Yes
REPAIR connection on circuit SDC02 (RD). 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 - 2.3L Service and Repair or Generator - 3.0L Service and Repair. TEST the system for normal operation.
No
INSTALL a new PCM.
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I10 CHECK FOR SHORTED CIRCUITS
- Ignition OFF.
- Disconnect: Generator C102a.
- 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%?
Yes
REPAIR short circuit on C102a-1 CDC15 (VT).
No
GO to I11.
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I11 CHECK THE PCM PID GENERATOR MONITOR INPUT TO THE PCM
- Connect a fused jumper wire between generator C102a-1, circuit CDC15 (VT), harness side and ground.
- Ignition ON.
- Monitor the GENMON PID while carrying out a Wiggle Test on the wire harness.
- Does the GENMON PID read 0%?
Yes
REPAIR open connection on circuit CDC15 (VT) C102a-1, and PCM C175e-26. CLEAR the DTCs. REPEAT the self-test. TEST the system for normal operation.
No
INSTALL a new generator. REFER to Generator - 2.3L Service and Repair or Generator - 3.0L Service and Repair. CLEAR the DTCs. REPEAT the self-test. TEST the system for normal operation.
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