P000A - Camshaft 'A' Position - Slow Response (Bank 1)
System
Powertrain (Engine & Gearbox)
Technical Description
The control module has detected a fault in the Camshaft 'A' Position (P000A). Affects cylinder bank 1 (bank 1 containing cylinder 1, firewall/right side).
Multimeter Test Points & Nominal Values
| Test Point / Component | Measurement | Nominal Target Range | Test Condition |
|---|---|---|---|
| Camshaft 'A' Position – Signal Voltage | Voltage (V) | 0.50 - 4.50 V (tracks operating range) | Ignition ON, connector engaged |
| 5 V Reference Voltage | Voltage (V) | 4.95 - 5.05 V | Ignition ON at sensor connector |
| Sensor Ground Voltage Drop | Voltage (V) | < 0.05 V (< 50 mV) | Under load to chassis ground |
| Signal Wire Continuity | Resistance (Ω) | < 0.5 Ω (Open = OL) | Disconnected harness between sensor and ECM |
Ignition ON, connector engaged
Ignition ON at sensor connector
Under load to chassis ground
Disconnected harness between sensor and ECM
Oscilloscope Waveform Analysis
100 ms/div, 1 V/divPossible Causes
Bank 1 specific:Inspect wiring harness to cylinder bank 1 (firewall/right bank, exposed to exhaust manifold heat).
Channel A:Verify dedicated wiring pins and signal pair for circuit A against the schematic.
Chafed or pinched wiring harness along the signal path to Camshaft 'A' Position
Poor ground connection or excessive voltage drop (> 0.1 V) at the ground point for Camshaft 'A' Position
Defective internal output driver or reference circuit in the control module for Camshaft 'A' Position
Symptoms
Recommended Solution
Compare signal voltage and resistance between circuit A and companion circuit B at module connector.
Cross-swap the component on Bank 1 with Bank 2 to rule out mechanical oil passages and internal timing wear.
Review freeze-frame environmental data and perform fundamental voltage-drop and resistance checks on the circuit.
Verify loaded supply voltage and harness terminal pins at Camshaft 'A' Position.
Check circuit continuity and ground-side voltage drop (< 0.05 V) for Camshaft 'A' Position.
Unplug the sensor:the signal must swing to a known rail. Replace the sensor or repair the wiring based on the result.
Mechanic's Tip
Always run a loaded voltage-drop test on the sensor ground with ignition ON. A drop above 0.1 V shifts the whole signal and tricks the module into setting sensor codes on a good sensor.