Test Procedure

WARNING: This page is about a different car, the 2007 Mercury Mariner and 2007 Ford Escape. However, it is still accessible from the selected car via links, so may be relevant.

QA1 CHECK FOR SELF-TEST DTC P1001

Is DTC P1001 present during self test?

Yes	No
GO to QA14.	GO to QA2.

QA2 VEHICLE INSPECTION AND VERIFY THE SELF-TEST PROCEDURE

NOTE: This pinpoint test addresses the following concerns:

Unable to communicate with the powertrain control module (PCM)
Unable to communicate with the transaxle control module (TCM)
Unable to activate the PCM self-test
Unable to activate the TCM self-test
Scan tool communication concern

Possible causes:

Damaged data link connector (DLC)
Incorrect self-test procedure
Open DLC harness circuit
Short in the DLC harness circuit or associated modules
Damaged voltage or ground circuits to the PCM or TCM
Damaged PCM
Damaged TCM

If the self-test or communication concern only occurred after an aborted module reprogram, the module may be blank. If this is the case, reprogram the module again before continuing with this pinpoint test.

Visually inspect the following for obvious signs of electrical damage:

Power distribution box fuses
Smart junction box (SJB) fuses
Harness wiring
Electrical connections

Repair/Install a new component as necessary.

Verify the correct procedure is used to activate the self-test for the scan tool. Refer to the DIAGNOSTIC METHODS article, Diagnostic Methods.

Was the correct self-test procedure used?

Yes	No
GO to QA3.	Correct procedure was not used for activating the Self-Test. RETURN to the SYMPTOM CHARTS article, Symptom Charts, Step 1: Powertrain Control Module (PCM) / Transaxle Control Module (TCM) Quick Test, and CARRY OUT the self-test using the correct procedure.

QA3 INSPECT THE VEHICLE AND SCAN TOOL DLC FOR DAMAGE

Key in OFF position.
Disconnect the scan tool.
Inspect the vehicle and scan tool DLC for damage.
Are there any concerns with the wiring or the DLC connection?

Yes	No
REPAIR as necessary. CLEAR the DTCs. REPEAT the self-test.	GO to QA4.

QA4 CHECK THE B+ VOLTAGE TO THE DLC

Measure the voltage between:

( + ) DLC, Harness Side	( - ) Vehicle Battery
B+ - Pin 16	Negative terminal

Is the voltage greater than 10.5 volts?

Yes	No
GO to QA5.	REPAIR the circuit. CLEAR the DTCs. REPEAT the self-test.

QA5 CHECK THE DLC CHASSIS GROUND CIRCUIT FOR AN OPEN IN THE HARNESS

Measure the voltage between:

( + ) DLC, Harness Side	( - ) DLC, Harness Side
B+ - Pin 16	CHGND - Pin 4

Is the voltage greater than 10.5 volts?

Yes	No
GO to QA6.	REPAIR the circuit. CLEAR the DTCs. REPEAT the self-test.

QA6 CHECK THE DLC SIGNAL GROUND CIRCUIT FOR AN OPEN IN THE HARNESS

Measure the voltage between:

( + ) DLC, Harness Side	( - ) DLC, Harness Side
B+ - Pin 16	SIGGND - Pin 5

Is the voltage greater than 10.5 volts?

Yes	No
GO to QA7.	REPAIR the circuit. CLEAR the DTCs. REPEAT the self-test.

QA7 CARRY OUT THE NETWORK TEST

NOTE: The purpose of this test step is to determine if the scan tool can communicate to the PCM by using the network test on the scan tool. The network test pings each module on the network and looks for a reply. If a PCM communication error message is encountered possible causes are:

Loss or intermittent loss of voltage or ground to the PCM
PCM to network communication problems (open or shorted data link (+) or (-) circuit from the PCM to the rest of the network modules or DLC).

NOTE: A typical PCM communication error message is Fail.

Key ON, engine OFF.
Carry out the network test.
Are there any PCM network error messages?

Yes	No
GO to QA8.	PCM test passed. GO to QA9.

QA8 CHECK THE VREF VOLTAGE TO THE FUEL RAIL PRESSURE TEMPERATURE (FRPT) SENSOR

NOTE: This test step determines if the PCM has voltage and ground.

Key in OFF position.
FRPT Sensor connector disconnected.
Key ON, engine OFF.

Measure the voltage between:

( + ) FRPT Sensor Connector, Harness Side	( - ) FRPT Sensor Connector, Harness Side
VREF - Pin 2	SIGRTN - Pin 4

Is the voltage reading between 4 and 6 volts?

Yes	No
PCM has voltage and ground. REFER to MODULE COMMUNICATIONS NETWORK to diagnose the module communications network.	refer to PINPOINT TEST C .

QA9 CHECK FOR TCM NETWORK ERROR MESSAGES

NOTE: A typical TCM communication error message is Fail.

Using the previous network test results. Check for TCM communication error messages.
Are there any TCM network error messages?

Yes	No
GO to QA10.	TCM test passed. GO to QA13.

QA10 CHECK THE TCM FOR VOLTAGE

Key in OFF position.
Transaxle Assembly-A connector disconnected.

Measure the voltage between:

( + ) Transaxle Assembly-A Connector, Harness Side	( - ) Vehicle Battery
B+ - Pin 12	Negative terminal

Is the voltage greater then 10.5 volts?

Yes	No
GO to QA11.	REPAIR the circuit. CLEAR the DTCs. REPEAT the self-test.

QA11 CHECK THE TCM FOR GROUND

Measure the resistance between:

( + ) Transaxle Assembly-A Connector, Harness Side	( - ) Vehicle Battery
GND - Pin 2, 8	Negative terminal
GND - Pin 2, 8	Negative terminal

Is the resistance less then 5 ohms?

Yes	No
GO to QA12.	REPAIR the circuit. CLEAR the DTCs. REPEAT the self-test.

QA12 CHECK THE VPWR FROM THE POWER SUSTAIN RELAY

Key ON, engine OFF.

Measure the voltage between:

( + ) Transaxle Assembly-A Connector, Harness Side	( - ) Vehicle Battery
PSR - Pin 4, 5	Negative terminal

Is the voltage above 10.5 volts.

Yes	No
TCM has voltage and ground. REFER to MODULE COMMUNICATIONS NETWORK to diagnose the module communications network.	REPAIR the circuit. CLEAR the DTCs. REPEAT the self-test.

QA13 CHECK THE OTHER MODULES FOR NETWORK ERROR MESSAGES

NOTE: Ignore optional equipment modules communication errors unless the module is related to the symptom being diagnosed.

Using the previous network test results. Check the other electronic control units (ECU)s for communication error messages.
Are there any communications network error messages?

Yes	No
REFER to MODULE COMMUNICATIONS NETWORK to diagnose the module communications network.	Test complete. RETURN to the SYMPTOM CHARTS article, Symptom Charts to continue diagnosis.

QA14 DTC P1001: KEY ON ENGINE RUNNING (KOER) NOT ABLE TO COMPLETE/ABORTED

Verify the correct procedure is used to activate the self-test for the scan tool. Refer to the DIAGNOSTIC METHODS article, Diagnostic Methods.
Is the correct self-test procedure used?

Yes	No
GO to QA15.	The correct procedure was not used for activating the Self-Test. RETURN to the SYMPTOM CHARTS article, Symptom Charts, Step 1: Powertrain Control Module (PCM) / Transaxle Control Module (TCM) Quick Test, and CARRY OUT the self-test using the correct procedure.

QA15 CHECK FOR ANY OTHER KOER DTCS

Are there any other KOER DTCs present?

Yes	No
If you are here for P1001 and other KOER DTCs are present, GO to Section 4 , DIAGNOSTIC TROUBLE CODE (DTC) CHARTS AND DESCRIPTIONS for pinpoint test direction. REPAIR the other DTCs first.	GO to QA16.

QA16 CHECK FOR ANY OTHER PCM DTCS

Are there any other PCM DTCs present?

Yes	No
DISREGARD the current diagnostic trouble code (DTC) at this time. DIAGNOSE the next DTC. GO toDIAGNOSTIC TROUBLE CODE (DTC) CHARTS AND DESCRIPTIONS .	GO toSymptom Charts, STEP 2: NO DIAGNOSTIC TROUBLE CODES (DTCS) PRESENT SYMPTOM CHART INDEX for direction to the proper Step 3 Symptom Chart.