Pinpoint Test I: DTCs P163C and P163D
Pinpoint Test
Pinpoint Test I: DTCs P163C and P163D
Refer to Wiring Diagram Set 12, Charging System for schematic and connector information. Diagrams By Number
Normal Operation
The PCM monitors the secondary generator output via the generator 2 monitor (GENMON2) circuit (generator field terminal circuit). If the PCM cannot read the GENMON2 circuit due to an open or short to ground, when the engine speed is greater than approximately 2,000 rpm, the secondary generator defaults to a steady voltage of approximately 13.5 volts and the PCM sends a message over the High Speed Controller Area Network (HS-CAN) to the Instrument Panel Cluster (IPC) through the Body Control Module (BCM) to illuminate the charging system warning indicator lamp.
- DTC P163C (Generator B Field Terminal Circuit Low) - The PCM sets this DTC if the GENMON circuit is shorted to ground, the "A" sense circuit is open or the B+ circuit is open. This DTC also sets by a faulted PCM or generator.
- DTC P163D (Generator B Field Terminal Circuit High) - The PCM sets this DTC if the GENMON2 circuit is open or shorted to power. This DTC can also be set by a faulted PCM or generator.
This pinpoint test is intended to diagnose the following:
- Fusible link
- Wiring, terminals or connectors
- Engine, generator and battery grounds
- Battery
- Secondary generator
- PCM
PINPOINT TEST I: DTCs P163C AND P163D
NOTE: Make sure battery voltage is greater than 12.2 volts prior to and during 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, Mounting and Cables Testing and Inspection. Pinpoint Tests
- Does the battery pass the condition test?
Yes
GO to I2.
No
INSTALL a new battery. REFER to Battery, Mounting and Cables Battery and Battery Tray. CLEAR the DTCs. REPEAT the self-test. TEST the system for normal operation.
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I2 CHECK THE GENERATOR B+ CONNECTION
- Ignition OFF.
- Inspect generator C1251B, circuit SDC02 (RD), harness side. Connection should be tight.
- Measure the voltage between generator C1251B, circuit SDC02 (RD) and ground.
- Is the generator connection tight and does the generator B+ measure battery voltage?
Yes
GO to I3.
No
REPAIR the generator B+ connection or circuit. CLEAR the DTCs. REPEAT the self-test. TEST the system for normal operation.
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I3 CHECK THE "A" SENSE VOLTAGE
- Disconnect: Generator C1251A.
- Measure battery voltage and record.
- Measure the voltage between generator C1251A-3, circuit SDC02 (RD), harness side and ground.
- Is the voltage equal to battery voltage?
Yes
GO to I4.
No
VERIFY fusible links are OK. If OK, REPAIR circuit SDC02 (RD). If not OK, REFER to the Wiring Diagrams to identify the possible causes of the circuit short. CLEAR the DTCs. REPEAT the self-test. TEST the system for normal operation. Diagrams By Number
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I4 MONITOR THE PCM PID GENERATOR MONITOR (GENMON2) WITH IGNITION ON/ENGINE OFF
- Connect: Generator C1251A.
- Ignition ON.
- NOTE: Many of the PCM PIDs selected will be monitored later in this pinpoint test.
- Select and monitor the following PCM PIDs:
- Generator Monitor (GENMON2).
- Generator Command (GENCMD2).
- Generator Voltage Desired (GENVDSD2).
- Engine Revolutions Per Minute (RPM).
- Module Supply Voltage (VPWR).
- Does the GENMON2 PID read 0%?
Yes
GO to I5.
No
GO to I10.
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I5 MONITOR THE PCM PIDs GENERATOR MONITOR (GENMON) AND GENERATOR VOLTAGE DESIRED (GENVDSD) WITH ENGINE RUNNING AND NO LOADS
- Start and idle the engine and turn all electrical accessories (lights, blower motor, etc.) off.
- With the engine at idle, wait at least 15 seconds for the GENVDSD2 PID to increase to greater than 13 volts.
- Monitor PID GENMON2 at idle.
- NOTE: On vehicles equipped with a manual transmission, the parking brake must be applied and the clutch pedal depressed in order to use the output state control RPM.
- Using output state control PID RPM, increase the engine rpm to 3,000 rpm.
- Monitor PID GENMON2.
- Does the GENMON2 PID read between 3% and 98% at engine idle speed and at 3,000 rpm?
Yes
GO to I6.
No
GO to I11.
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I6 MONITOR THE PCM PIDs GENERATOR MONITOR 2 (GENMON2), GENERATOR VOLTAGE DESIRED 2 (GENVDSD2) WITH THE ENGINE AT IDLE LOADS ON
- Decrease the engine speed to 500 rpm using active command PID RPM and monitor PIDs.
- NOTE: On vehicles with low electrical loads, it is necessary to make sure that all of the vehicles electrical loads are turned ON to determine the maximum GENMON2 PID value. The GENMON2 PID value may not reach between the desired 95%-98% on a low load vehicle with minimal electrical accessories. As long as the GENMON2 PID increases significantly with all of the electrical loads ON, answer YES to the question below.
- Determine the maximum GENMON2 PID value by lowering engine idle rpm to 500 rpm or less using output state control PID RPM and turn ON all electrical accessories until the module supply voltage (VPWR) PID is less than the GENVDSD2 PID by at least 0.7 volt. Under this condition the GENMON2 PID should read between 95% and 98%.
- Does the GENMON2 PID read between 95% and 98%?
Yes
GO to I7.
No
GO to I11.
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I7 MONITOR THE PCM PIDs GENERATOR MONITOR 2 (GENMON2), MODULE SUPPLY VOLTAGE (VPWR) AND GENERATOR VOLTAGE DESIRED 2 (GENVDSD2) WITH THE ENGINE AT 3,000 RPM
- Increase the engine speed to 3,000 rpm using active command PID RPM and monitor PIDs.
- NOTE: If GENMON2 PID does not remain below 85%, make sure that the battery is at an acceptable state of charge and that all electrical accessories are off.
- Monitor PIDs VPWR, GENVDSD2 and GENMON2.
- Does the VPWR PID remain within ±0.5 volt of the GENVDSD2 PID when the GENMON2 PID is less than 85%?
Yes
GO to I8.
No
GO to I11.
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I8 CHECK THE GENERATOR B+ RESISTANCE
- Ignition OFF.
- NOTE: Failure to disconnect the battery will result in false resistance readings.
- Disconnect the battery. Refer to Battery, Mounting and Cables Battery Disconnect / Connect.
- Disconnect: Generator C1251B.
- Measure the resistance between generator C1251B, component side and the generator housing.
- Is the resistance greater than 25K ohms?
Yes
GO to I9.
No
INSTALL a new generator. REFER to Generator - 6.7L Diesel, Dual Generator Generator - Dual Generator. CLEAR the DTCs. REPEAT the self-test. TEST the system for normal operation.
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I9 CHECK THE RESISTANCE OF THE VOLTAGE REGULATOR INTERNAL CIRCUITS TO GROUND
- Disconnect: Generator C1251A.
- Measure the resistance between generator C1251A, component side and ground as follows:
- Are the resistance values as indicated?
Yes
The fault is not present at this time. This may indicate an intermittent fault. CARRY OUT a wiggle test on the charging system circuits to try and recreate the concern. CHECK generator connections for corrosion, loose connections and/or bent terminals. REPAIR as necessary. CLEAR the DTCs. REPEAT the self-test. TEST the system for normal operation.
No
INSTALL a new generator. REFER to Generator - 6.7L Diesel, Dual Generator Generator - Dual Generator. CLEAR the DTCs. REPEAT the self-test. TEST the system for normal operation.
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I10 CHECK THE PCM PID GENERATOR MONITOR 2 (GENMON2) INPUT TO THE PCM
- Ignition OFF.
- Disconnect: Generator C1251A.
- Connect a fused jumper wire between generator C1251A-1, circuit CDC47 (WH), harness side and ground.
- Ignition ON.
- Monitor the GENMON2 PID while performing a wiggle test on the generator wiring harness.
- Does the GENMON2 PID read 0%?
Yes
GO to I14.
No
GO to I15.
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I11 "A" SENSE CIRCUIT LOAD TEST
NOTICE: The following step uses a test light to simulate normal circuit loads. Use only the test light recommended in the Special Tools table. To avoid connector terminal damage, use the Flex Probe Kit for the test light probe connection to the vehicle. Do not use the test light probe directly on any connector.
NOTE: This step puts a load on the "A" sense circuit. If there are corroded or loose connections, loading the circuit may help show the fault. A 250-350 mA incandescent 12-volt test lamp is required for this step. This circuit will not be loaded properly using an LED-style test lamp.
- Ignition OFF.
- Disconnect: Generator C1251A (if not previously disconnected).
- Ignition ON.
- Using a 12-volt test lamp connected to ground, check for voltage at C1251A-3, circuit SDC02 (RD), harness side.
- Does the test lamp illuminate?
Yes
GO to I12.
No
VERIFY fusible links are OK. If OK, REPAIR circuit SDC02 (RD). If not OK, REFER to the Wiring Diagrams to identify the possible causes of the circuit short. CLEAR the DTCs. REPEAT the self-test. TEST the system for normal operation. Diagrams By Number
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I12 B+ CIRCUIT LOAD TEST
NOTE: This step puts a load on the B+ circuit. If there are corroded or loose connections, loading the circuit may help show the fault. A 250-350 mA incandescent 12-volt test lamp is required for this step. This circuit will not be loaded properly using an LED-style test lamp.
- Ignition OFF.
- Disconnect: Generator C1251B.
- Using a 12-volt test lamp connected to ground, check for voltage at C1251B-1, circuit SDC02 (RD), harness side.
- Does the test lamp illuminate?
Yes
GO to I13.
No
REPAIR circuit SDC02 (RD) for high resistance. CLEAR the DTCs. REPEAT the self-test. TEST the system for normal operation.
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I13 CHECK GENCOM2 CIRCUIT FOR DAMAGE OR AN OPEN
- Ignition OFF.
- Disconnect: PCM C1232B.
- Inspect the following harness connectors for damaged or pushed-out pins:
- PCM C1232B-54, circuit CDC48 (YE/GN).
- Generator C1251A-2, circuit CDC48 (YE/GN).
- Measure the resistance between PCM C1232B-54, circuit CDC48 (YE/GN), harness side and generator C1251A-2, circuit CDC48 (YE/GN), harness side.
- Are the connectors and pins free of damage and is the resistance less than 0.5 ohm?
Yes
GO to I14.
No
REPAIR circuit CDC09 (YE) or CDC10 (BU/OG). CLEAR the DTCs. REPEAT the self-test. TEST the system for normal operation.
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I14 COMPARE THE PCM PIDs GENERATOR MONITOR 2 (GENMON2) AND GENERATOR COMMAND 2 (GENCMD2)
- Connect: Generator C1251B (if previously disconnected).
- Connect: PCM C1232B (if previously disconnected).
- Connect a fused jumper wire between generator C1251A-1, circuit CDC47 (WH), harness side and generator C1251A-2, circuit CDC48 (YE/GN), harness side.
- Start the engine.
- Using output state control, set the GENVDSD2 PID to 14.0 volts.
- Monitor the GENMON2 and GENCMD2 PIDs while performing a wiggle test on the generator wiring harness.
- Does the GENMON2 PID read within 2% of the GENCMD2 PID?
Yes
INSTALL a new generator. REFER to Generator - 6.7L Diesel, Dual Generator Generator - Dual Generator. CLEAR the DTCs. REPEAT the self-test. TEST the system for normal operation.
No
GO to I16.
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I15 INSPECT GENERATOR CIRCUITS AND CONNECTORS
- Ignition OFF.
- Disconnect: PCM C1232B.
- Inspect the following connector pins for damage and/or corrosion:
- generator C1251A-1, circuit CDC47 (WH)
- PCM C1232B-15, circuit CDC47 (WH)
- Are circuits and connectors OK?
Yes
INSTALL a new PCM. REFER to Electronic Engine Controls - Diesel Engine Powertrain Control Module (PCM). CLEAR the DTCs. REPEAT the self-test. TEST the system for normal operation.
No
REPAIR the circuit(s) and/or connector(s) as necessary. CLEAR the DTCs. REPEAT the self-test. TEST the system for normal operation.
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I16 INSPECT PCM CIRCUITS
- Ignition OFF.
- Disconnect: PCM C1232B.
- Inspect the following connector pins for damage and/or corrosion:
- PCM C1232B-15, circuit CDC47 (WH)
- PCM C1232B-54, circuit CDC48 (YE/GN)
- Are the connectors OK?
Yes
INSTALL a new PCM. REFER to Electronic Engine Controls - Diesel Engine Powertrain Control Module (PCM). CLEAR the DTCs. REPEAT the self-test. TEST the system for normal operation.
No
REPAIR the affected circuit(s). CLEAR the DTCs. REPEAT the self-test. TEST the system for normal operation.
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