P0A5B
Diagnostic Routine I
Diagnostic Overview
P0A5A:00, P0A5B:00, P0A5C:00
Refer to Wiring Diagram Set 12 for schematic and connector information Electrical Diagrams.
Normal Operation and Fault Conditions
The generator current sensor is a hall effect sensor attached to the generator B+ cable. It is supplied a 5 volt reference and ground from the PCM (Powertrain Control Module). The PCM (Powertrain Control Module) reads the generator current sensor feedback voltage to determine how much current is flowing through the generator B+ cable.
DTC (Diagnostic Trouble Code) Fault Trigger Conditions
Visual Inspection and Diagnostic Pre-checks
- Inspect the generator current sensor.
- Inspect the wiring, terminals or connectors.
- Inspect for loose or corroded connections.
Pinpoint Test
1. CHECK THE PCM (Powertrain Control Module) DTCs (Diagnostic Trouble Codes)
1. Ignition ON.
2. Using a scan tool, perform PCM (Powertrain Control Module) self-test.
Is DTC (Diagnostic Trouble Code) P0A5A present?
2. CHECK THE GENERATOR CURRENT SENSOR
1. Ignition OFF.
2. Inspect the generator current sensor for the following:
- Physical damage
- Corrosion
- Disconnected electrical connector
- Disconnected from generator B+ cable
- Debris between the generator current sensor and the generator B+ cable
Are any of these conditions found during inspection?
3. CHECK THE GENERATOR CURRENT SENSOR REFERENCE VOLTAGE CIRCUIT FOR AN OPEN
1. Ignition OFF.
2. Disconnect: Generator Current Sensor.
3. Ignition ON.
4. Measure:
Is the voltage greater than 4.7 volts?
4. CHECK THE GENERATOR CURRENT SENSOR SIGNAL RETURN CIRCUIT FOR AN OPEN
1. Measure:
Is the voltage greater than 4.7 volts?
5. CHECK THE GENERATOR CURRENT SENSOR FEEDBACK CIRCUIT FOR A SHORT TO GROUND
1. Ignition OFF.
2. Disconnect: PCM (Powertrain Control Module) C175B (3.5L) or C1381B (2.0L).
3. Measure:
Is the resistance greater than 10,000 ohms?
6. CHECK THE GENERATOR CURRENT SENSOR FEEDBACK CIRCUIT FOR AN OPEN
1. For 3.5L measure:
2. For 2.0L measure:
Is the resistance less than 3 ohms?
7. CHECK THE GENERATOR CURRENT SENSOR FEEDBACK CIRCUIT FOR A SHORT TO VOLTAGE
1. Ignition OFF.
2. Disconnect: Generator Current Sensor.
3. Disconnect: PCM (Powertrain Control Module) C175B (3.5L) or C1381B (2.0L).
4. Ignition ON.
5. Measure:
Is any voltage present?
8. CHECK THE GENERATOR CURRENT SENSOR FEEDBACK CIRCUIT FOR A SHORT TO THE SIGNAL RETURN OR VOLTAGE REFERENCE CIRCUIT
1. Ignition OFF.
2. Measure:
Are the resistances greater than 10,000 ohms?
9. CHECK THE GENERATOR CURRENT SENSOR CONNECTION
1. Ignition OFF.
2. Disconnect: Generator Current Sensor.
3. Inspect the generator current sensor connector for:
- corrosion
- pushed-out terminals
- damaged terminals
4. Connect and correctly seat the generator current sensor connector.
5. Ignition ON.
6. Clear the DTCs (Diagnostic Trouble Codes).
7. Using a scan tool, perform PCM (Powertrain Control Module) self-test.
Did the DTC (Diagnostic Trouble Code) return?
10. CHECK FOR CORRECT PCM (Powertrain Control Module) OPERATION
1. Ignition OFF.
2. Disconnect and inspect all PCM (Powertrain Control Module) connectors.
3. Repair:
- corrosion (install new connector or terminals - clean module pins)
- damaged or bent pins - install new terminals/pins
- pushed-out pins - install new pins as necessary
4. Reconnect the PCM (Powertrain Control Module) connectors. Make sure they seat and latch correctly.
5. Operate the system and determine if the concern is still present.
Is the concern still present?
