DTC P0342 Camshaft Position (CMP) Sensor Circuit Low Voltage. Pontiac Grand Am 1999

For 1990-2009 cars only

Makes 🢒 Pontiac 🢒 1999 🢒 Grand Am 🢒 DTC 🢒 DTC P0342 Camshaft Position (CMP) Sensor Circuit Low Voltage

Engine Controls Components
Cell 23: Ignition Controls
OBD II Symbol Description Notice
Powertrain Control Module Connector End Views With EGR
Handling ESD Sensitive Parts Notice

Circuit Description

The camshaft position (CMP) sensor correlates the crankshaft to camshaft position so that the Powertrain Control Module (PCM) can determine which cylinder is ready to be fueled by the injector. The CMP sensor also determines which cylinder is misfiring when a misfire is present. If the PCM receives an intermittent signal from the CMP, then the CMP Resync Counter will increment. When the PCM cannot use the information from the CMP sensor, a DTC is set and the PCM will fuel the engine by using the alternating synchronous double fire (ASDF) method.

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 (With EGR)

•	The Malfunction Indicator Lamp (MIL) illuminates.

•	The PCM records the operating conditions at the time when the diagnostic fails. This information stores in the Freeze Frame and Failure Records buffers.

•	A history DTC stores.

•	The coolant fan turns ON.

Action Taken When the DTC Sets (Without EGR)

•	The Malfunction Indicator Lamp (MIL) will illuminate after two consecutive ignition cycles in which the diagnostic runs with the fault active.

•	The PCM records the operating conditions at the time when the diagnostic fails. This information stores in the Freeze Frame and Failure Records buffers.

•	A history DTC stores.

•	The coolant fan turns ON.

Conditions for Clearing the MIL/DTC

•	The MIL will turn OFF after three consecutive ignition cycles in which the diagnostic runs without a fault.

•	A history DTC will clear after 40 consecutive warm-up cycles without a fault.

•	The MIL/DTCs can be cleared by using the scan tool.

Diagnostic Aids

•	An Intermittent problem may be caused by the following conditions:

-	Poor electrical connection

-	Rubbed-through wire insulation

-	Broken wire inside the insulation

•	Thoroughly check any suspected circuitry for the following conditions:

-	Backed-out terminals

-	Improper mating

-	Broken locks

-	Improperly formed connectors

-	Damaged terminals

-	Poor terminal to wiring connections

-	Physical damage to the wiring harness

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 the output of the CMP sensor. If there is a varying voltage, then the problem is in the CMP signal circuit. If there is no varying voltage, then problem is in the CMP sensor electrical connections or is a malfunctioning CMP sensor.

Reprogram the replacement PCM and perform the crankshaft position system variation learn procedure. Refer to the latest Techline procedures for PCM reprogramming and the Crankshaft Position System Variation Learn for the crankshaft position system variation learn procedure.

DTC P0342-Camshaft Position (CMP) Sensor Circuit Low Input

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.
Idle the engine.
Observe the CMP Active counter with the scan tool.

Is the CMP Active counter incrementing?

Go to Step 3

Go to Step 4

Review the Freeze Frame data and record the parameters.
Operate the vehicle within the Freeze Frame conditions and Conditions For Running The DTC as specified.

Is the CMP Active Counter incrementing?

Go to Step 16

Go to Step 4

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

Did the test light illuminate?

Go to Step 5

Go to Step 6

Connect a test light to B+.
Probe the CMP electrical connector ground circuit terminal.

Did the test light illuminate?

Go to Step 7

Go to Step 8

Turn OFF the ignition switch.
Check the CMP ignition positive voltage circuit for the following conditions:

•	Poor terminal connection

•	Open in the ignition positive voltage circuit

•	Short to ground in the ignition positive voltage circuit

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

Was a repair necessary?

Go to Step 16

Go to Step 15

Turn OFF the ignition switch.
Use the correct test adapters from the J 35616 connector test adapter kit and install adapters to the CMP electrical connector terminals B and C.
Install the correct adapters to the CMP sensor terminals B and C.
Connect fused jumper wires between each of the adapters to the correct corresponding terminals on the CMP sensor.
Remove the fuel pump fuse.
Connect a DMM to ground.
Select the Hz scale on the DMM.
Probe the CMP signal terminal A of the CMP sensor.
Crank the engine.

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

0.5-2.6 Hz

Go to Step 9

Go to Step 14

Turn OFF the ignition switch.
Check the CMP ground circuit for the following conditions:

•	Poor electrical terminal connection(s) at the PCM

•	Open circuit

Repair the circuit or Connection(s) as necessary. Refer to Wiring Repairs in Wiring Systems.

Was a repair necessary?

Go to Step 16

Go to Step 15

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

Does the test light illuminate?

Go to Step 12

Go to Step 10

Connect a test light to B+.
Probe the CMP sensor signal harness connection terminal A.

Does the test light illuminate?

Go to Step 13

Go to Step 11

Check the CMP sensor signal circuit for the following conditions:

•	Open Circuit

•	Poor electrical terminal connection at the CMP sensor

Repair the CMP sensor signal circuit as necessary. Refer to Wiring Repairs in Wiring Systems.

Was a repair necessary?

Go to Step 16

Go to Step 15

Turn OFF the ignition switch.
Repair the short to B+ in the CMP signal circuit. Refer to Wiring Repairs in Wiring Systems.

Is the action complete?

Go to Step 16

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

Is the action complete?

Go to Step 16

Turn OFF the ignition switch.
Check for a poor electrical connection at the CMP sensor electrical connector. Refer to Wiring Repairs in Wiring Systems.

If the CMP electrical connection is OK, replace the Camshaft Position (CMP) sensor. Refer to the Camshaft Position Sensor Replacement .

Is the action complete?

Go to Step 16

Turn OFF the ignition switch.
Check for a poor electrical terminal connection.
If the terminal connection is OK, then replace the PCM. Refer to the Powertrain Control Module Replacement .

Is the action complete?

Go to Step 16

Install the fuel pump fuse if still removed.
Reconnect the CMP electrical connector if the electrical 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 applicable DTC table

System OK