DTC P0342 Camshaft Position (CMP) Sensor Circuit Low Voltage. GMC Truck Sonoma Pickup

For 1990-2009 cars only

Makes 🢒 GMC_Truck 🢒 1999 🢒 Sonoma Pickup - 2WD 🢒 DTC 🢒 DTC P0342 Camshaft Position (CMP) Sensor Circuit Low Voltage

Engine Controls Components
Cell 20: Ignition Controls
OBD II Symbol Description Notice
Powertrain Control Module Connector End Views
Handling ESD Sensitive Parts Notice

Circuit Description

The camshaft position (CMP) sensor indicates the camshaft position so the powertrain control module (PCM) can determine which cylinder is misfiring when a misfire is present. Whenever the PCM receives an intermittent signal from the CMP, then the CMP actrivity counter will increment. In order to set a DTC, the PCM must see a minimum number of resyncs within a maximum time.

Conditions for Running the DTC

The engine is running.

Conditions for Setting the DTC

The CMP Active Counter is not incrementing.

Action Taken When the DTC Sets

•	The control module illuminates the malfunction indicator lamp (MIL) if a failure is detected during 2 consecutive key cycles.

•	The control module sets the DTC and records the operating conditions at the time the diagnostic failed. The failure information is stored in the scan tool Freeze Frame/Failure Records.

Conditions for Clearing the MIL or DTC

•	The control module turns OFF the MIL after 3 consecutive drive trips when the test has run and passed.

•

A history DTC will clear if no fault conditions have been detected for 40 warm-up cycles. A warm-up cycle occurs when the coolant temperature has risen 22°C (40°F) from the startup coolant temperature and the engine coolant reaches a temperature that is more than 70°C (158°F) during the same ignition cycle.

•	Use a scan tool in order to clear the DTCs.

Diagnostic Aids

•	Thoroughly check all circuitry for proper mating, broken locks, improperly formed or damaged terminals, or physical damage to the wiring harness.

•	Whenever the PCM sees less than 15 resyncs in 256 seconds, the counter resets to 0. Anytime a poor connection is present, the Cam Sensor Reference Activity counter stops incrementing and the Cam Sensor Resync Counter starts to increment.

An intermittent may be caused by any of the following conditions:

•	A poor connection

•	Rubbed through wire insulation

•	A broken wire inside the insulation

Thoroughly check any circuitry that is suspected of causing the intermittent complaint. Refer to Intermittents and Poor Connections Diagnosis in Wiring Systems.

If a repair is necessary, refer to Wiring Repairs or Connector Repairs in Wiring Systems.

Test Description

The numbers below refer to the step numbers on the Diagnostic Table.

The Powertrain OBD System Check prompts you to complete some of the basic checks and to store the freeze frame and failure records data on the scan tool if applicable. This creates an electronic copy of the data captured when the malfunction occurred. The scan tool stores this data for later reference.

This step determines if the DTC P0342 is the result of a hard malfunction or an intermittent condition.

This step determines if the voltage is available to the CMP sensor through the PCM.

This step checks for a signal from the CMP sensor. It is necessary to supply B+ to the CMP sensor ignition positive voltage terminal in order for the CMP sensor to have B+ supplied to the CMP sensor. While cranking the engine, the CMP sensor will send a varying voltage signal that can be read by the DMM as a frequency check.

Program the replacement PCM and perform the Crankshaft Position System Variation Learn Procedure. Refer to the latest Techline procedures for PCM programming

Step

Action

Value(s)

Yes

Did you perform the Powertrain On-Board Diagnostic (OBD) System Check?

Go to Step 2

Go to Powertrain On Board Diagnostic (OBD) System Check

Install a scan tool.
Start the engine.
With the engine idling observe the CMP Active counter with the scan tool.

Is the CMP active counter incrementing?

Go to Step 3

Go to Step 4

Turn ON the ignition leaving the engine OFF.
Review the Freeze Frame data and record the parameters.
Start the engine.
Operate the vehicle within the Freeze Frame conditions and Conditions For Setting The DTC as specified.

Is the CMP active counter incrementing?

Go to Step 14

Go to Step 4

Turn ON the ignition leaving the engine OFF.
Disconnect the Camshaft Position (CMP) sensor harness connector.
Connect a test lamp to ground.
Probe the battery positive voltage terminal of the CMP harness connector.

Did the test lamp illuminate?

Go to Step 5

Go to Step 6

Connect a test lamp to B+.
Probe the CMP harness connector ground terminal.

Did the test lamp illuminate?

Go to Step 7

Go to Step 8

Check for the following conditions on the CMP battery positive voltage circuit:

•	Poor connection

•	Open connection

Repair the circuit as necessary. Refer to Connector Repairs in Wiring Systems.

Was a repair necessary?

Go to Step 16

Go to Step 15

Turn OFF the ignition.
Use the correct test adapters from the J 35616 and install adapters between the engine harness connectors at the CMP ignition positive voltage circuit and the CMP sensor ground circuit.
Connect the fused jumper wires between each of the adapters to the correct corresponding terminals on the CMP sensor.
Remove the fuel pump fuse.
Connect a J 39200 DMM to ground.
Select the Hz scale on the J 39200 DMM.
Probe the CMP sensor signal circuit of the CMP sensor.
Crank the engine and observe the J 39200 DMM.

Does the DMM display a frequency reading that is varying between the specified values?

0.5-2.6 Hz

Go to Step 9

Go to Step 14

Check for the following conditions on the CMP sensor ground circuit:

•	Poor connection

•	Open connection

Repair the circuit as necessary. Refer to Connector Repairs in Wiring Systems.

Was a repair necessary?

Go to Step 16

Go to Step 15

Turn OFF the ignition.
Disconnect the PCM harness connector C1.
Remove all the fused jumper wires and test adapters from the CMP sensor and the CMP sensor harness connector.
Turn ON the ignition leaving the engine OFF.
Connect a test lamp to ground.
Probe the CMP sensor signal terminal at the CMP sensor connector with the test lamp.

Does the test lamp illuminate?

Go to Step 12

Go to Step 10

Connect a test lamp to B+.
Probe the CMP sensor signal circuit with the test lamp.

Does the test lamp illuminate?

Go to Step 13

Go to Step 11

Check the CMP sensor signal circuit for the following conditions:

•

Open

•	Poor connection at the CMP sensor.

Repair the circuit as necessary. Refer to Wiring Repairs or Connector Repairs in Wiring Systems.

Was a repair necessary?

Go to Step 16

Go to Step 15

Turn OFF the ignition.
Repair the short to voltage in the CMP sensor signal circuit. Refer to Wiring Repairs in Wiring Systems.

Is the action complete?

Go to Step 16

Turn OFF the ignition.
Repair the short to ground in the CMP sensor signal circuit. Refer to Wiring Repairs in Wiring Systems.

Is the action complete?

Go to Step 16

Turn OFF the ignition.
Check for a poor connection at the CMP sensor harness connector.
Repair the connection as necessary. Refer to Connector Repairs in Wiring Systems.
If the connection is OK, replace the CMP sensor. Refer to Camshaft Position Sensor Replacement

Is the action complete?

Go to Step 16

Turn OFF the ignition.
Check for a poor connection at the PCM harness connector.
Repair the connection as necessary. Refer to Connector Repairs in Wiring Systems.
If the connection is OK, then replace the PCM. Refer to Powertrain Control Module Replacement/Programming .

Is the action complete?

Go to Step 16

Install the fuel pump fuse if still removed.
Reconnect the CMP harness connector if the connector is still disconnected.
Clear the DTCs with the scan tool.
Start the engine.
Idle the engine at the normal operating temperature.
Operate the vehicle within the conditions for running this DTC as specified in the supporting text.

Does the scan tool indicate that this diagnostic has ran and passed?

Go to Step 17

Go to Step 2

Check to see if any additional DTCs are set.

Does the scan tool display any DTCs that you have not diagnosed?

Go to the applicable DTC table

System OK