Test Procedure

WARNING: This page is about a different car, the 2006 Mercury Mariner and 2006 Ford Escape. However, it is still accessible from the selected car via links, so may be relevant.

DR1 CONTINUOUS MEMORY DTC P0340: CHECK IF THE ENGINE WILL START

Attempt to start engine.

Does the engine start?

Yes	No
GO to DR2.	The concern is elsewhere. RETURN to SYMPTOM CHARTS for further direction.

DR2 CONTINUOUS MEMORY DTC P0340: CLEAR AND ATTEMPT TO REGENERATE THE DTC

Clear the DTCs.
Increase the engine speed to greater than 1,500 RPM for 10 seconds.
Repeat this 3 times.
Check for self-test DTCs.

Is DTC P0340 present?

Yes	No
Key in OFF position. A hard fault is present. GO to DR3.	Key in OFF position. GO to DR8.

DR3 CHECK THE CMP SENSOR RESISTANCE

NOTE: The CMP sensor resistance values change significantly with temperature rise.

CMP Sensor connector disconnected.

Measure the resistance between:

( + ) CMP Sensor Connector, Component Side	( - ) CMP Sensor Connector, Component Side
CMP - Pin 2	SIGRTN - Pin 1

Is the resistance between 250 ohms - 1K ohms?

Yes	No
GO to DR4.	INSTALL a new CMP sensor.

DR4 CHECK THE CMP CIRCUIT FOR A SHORT TO POWER IN THE HARNESS

PCM connector disconnected.
Key ON, engine OFF.

Measure the voltage between:

( + ) CMP Sensor Connector, Harness Side	( - ) Vehicle Battery
CMP - Pin 2	Negative terminal

Is the voltage less than 1 V?

Yes	No
Key in OFF position. GO to DR5.	REPAIR the short circuit.

DR5 CHECK THE CMP CIRCUIT FOR AN OPEN IN THE HARNESS

NOTE: Refer to the PCM connector pin numbers in the beginning of this pinpoint test. VR-type sensors are susceptible to electrical interference (noise). Harness shielding, where present, should be reinstalled properly when removed for testing.

Measure the resistance between:

( + ) PCM Connector, Harness Side	( - ) CMP Sensor Connector, Harness Side
CMP - Pin E10	CMP - Pin 2
SIGRTN - Pin B41, E41	SIGRTN - Pin 1

Are the resistances less than 5 ohms?

Yes	No
GO to DR6.	REPAIR the open circuit.

DR6 CHECK THE CMP CIRCUIT(S) FOR A SHORT TO SIGRTN OR GND IN THE HARNESS

Measure the resistance between:

( + ) CMP Sensor Connector, Harness Side	( - ) CMP Sensor Connector, Harness Side
CMP - Pin 2	SIGRTN - Pin 1

Measure the resistance between:

( + ) CMP Sensor Connector, Harness Side	( - ) Vehicle Battery
CMP - Pin 2	Negative terminal

Is the resistance greater than 10K ohms?

Yes	No
GO to DR7.	REPAIR the short circuit.

DR7 CHECK THE CMP SENSOR OUTPUT

PCM connector connected.
CMP Sensor connector disconnected.
Crank the engine using the engine cranking diagnostic mode. Refer to DIAGNOSTIC MODES .
Digital multimeter on low voltage AC scale.

Measure the voltage between:

( + ) CMP Sensor Connector, Component Side	( - ) CMP Sensor Connector, Component Side
CMP - Pin 2	SIGRTN - Pin 1

Is the voltage greater than 0.25 V?

Yes	No
GO to DR9.	INSTALL a new CMP sensor.

DR8 CHECK THE CMP CIRCUIT FOR AN INTERMITTENT CONCERN

Access the PCM and monitor the CMPFM PID.
While observing the PID, wiggle, shake, and bend small sections of the wiring harness working from the sensor to the PCM.

Is a concern present during the wiggle test?

Yes	No
ISOLATE the fault and REPAIR as necessary.	GO to Pinpoint Test Z .

DR9 CHECK FOR CORRECT PCM OPERATION

Disconnect all the PCM connectors.
Visually inspect for:
- pushed out pins.
- corrosion.
Connect all the PCM connectors and make sure they seat correctly.
Carry out the PCM self-test and verify the concern is still present.

Is the concern still present?

Yes	No
INSTALL a new PCM. REFER to FLASH ELECTRICALLY ERASABLE PROGRAMMABLE READ ONLY MEMORY (EEPROM) .	The system is operating correctly at this time. The concern may have been caused by a loose or corroded connector.