Crankshaft and camshaft position sensor comparison

The purpose of this test is to observe the output from the AC-excited Crank Angle Sensor while monitoring the output from the Camshaft Position Sensor, to check for any unwanted offset in timing between the two sensors which could indicate a slipped timing belt or a stretched timing chain.

Connection guidance

Connection for diagnostic work will vary dependent on application.

Technicians should whenever possible gain access to the test circuit without damage to seals and insulation. If this is not possible then make sure appropriate repairs are completed.

General connection advice

PicoScope offers a range of options within the test kits.

Dependent on difficulty of access, choose from:

  1. Breakout leads.
  2. Back-pinning probes.

Testing sensors and actuators (to include relevant circuit/connectors):

  • When testing a sensor, it is desirable to gain access at the control unit.
  • When testing an actuator, it is desirable to gain access at the actuator.

How to perform the test

Channel A

Plug a BNC test lead into Channel A on the PicoScope. Fit a large black  clip on the test lead with the black moulding (negative) and a Back-pinning Probe onto the test lead with the coloured moulding (positive). Place the black clip on the battery negative terminal and probe the crankshaft position sensor's negative (or number 1) terminal with the Back-pinning Probe as illustrated in Figure. 2.

Alternatively connections can be made using the TA012 breakout lead. Connect the BNC test lead directly to the two shrouded plugs on the breakout lead. If a smaller-than-anticipated waveform is shown, try reversing the connections. Connection of the breakout lead is illustrated in Figure 2.

Channel B

Plug a BNC test lead into Channel B on the PicoScope. Place a large black clip on the test lead with the black moulding (negative) and a Back-pinning Probe onto the test lead with the coloured moulding (positive). Probe the outputs of the camshaft position sensor until the larger waveform is displayed, the smaller waveform being the earth return.

Alternatively the TA012 two-pin test lead adapter can be used, as illustrated in Figure 3.

With the example waveform displayed on the screen you can now hit the space bar to start looking at live readings.

Example waveform

Waveform notes

In this waveform we can observe the output voltage from the AC-excited Crank Angle Sensor (shown in blue) at the same time as monitoring the inductive Camshaft Position Sensor trace (shown in red). The main reason for evaluating these two waveforms together is to look for any unwanted offset in timing between the two sensors, which could indicate a slipped timing belt or a stretched timing chain.

Waveform Library

Go to the drop-down menu bar at the lower left corner of the Waveform Library window and select, Crankshaft sensor.

Example hall effect sensor

Example inductive sensor

Further guidance

Selection of component related Diagnostic Trouble Codes (DTCs)

P0335 - CKP Sensor A Circuit Performance

P0336 - Crankshaft Position (CKP) Sensor A Performance

P0337 - Crankshaft Position (CKP) Sensor Circuit Low Duty Cycle

P0338 - Crankshaft Position (CKP) Sensor Circuit High Duty Cycle

P0339 - Crankshaft Position (CKP) Sensor Circuit Intermittent

P0340 : Camshaft Position Sensor A - Circuit Malfunction (Bank 1)

P0341 : Camshaft Position Sensor A - Circuit Range/Performance (Bank 1)

P0342 : Camshaft Position Sensor A - Circuit Low Input (Bank 1)

P0343 : Camshaft Position Sensor A - Circuit High Input (Bank 1)

P0344 : Camshaft Position Sensor A - Circuit Intermittent (Bank 1)

P0345 : Camshaft Position Sensor A - Circuit Malfunction (Bank 2)

P0346 : Camshaft Position Sensor A - Circuit Range/Performance (Bank 2)

P0347 : Camshaft Position Sensor A - Circuit Low Input (Bank 2)

P0348 : Camshaft Position Sensor A - Circuit High Input (Bank 2)

P0349 : Camshaft Position Sensor A - Circuit Intermittent (Bank 2)

P0365 : Camshaft Position Sensor B - Circuit Malfunction (Bank 1)

P0366 : Camshaft Position Sensor B - Circuit Range/Performance (Bank 1)

P0367 : Camshaft Position Sensor B - Circuit Low Input (Bank 1)

P0368 : Camshaft Position Sensor B - Circuit High Input (Bank 1)

P0369 : Camshaft Position Sensor B - Circuit Intermittent (Bank 1)

P0390 : Camshaft Position Sensor B - Circuit Malfunction (Bank 2)

P0391 : Camshaft Position Sensor B - Circuit Range/Performance (Bank 2)

P0392 : Camshaft Position Sensor B - Circuit Low Input (Bank 2)

P0393 : Camshaft Position Sensor B - Circuit High Input (Bank 2)

P0394 : Camshaft Position Sensor B - Circuit Intermittent (Bank 2)

GT151-4

Disclaimer
This help topic is subject to changes without notification. The information within is carefully checked and considered to be correct. This information is an example of our investigations and findings and is not a definitive procedure. Pico Technology accepts no responsibility for inaccuracies. Each vehicle may be different and require unique test settings.

Suitable accessories

  • Premium 6-way breakout lead set

    £269.00

  • Back-pinning Probe Set

    £40.00

  • Flexible Back-pinning Probe

    £3.00

  • PicoScope Battery Clip

    £2.75

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Guided test: Crankshaft and camshaft position sensor comparison