Test Procedure
- QA1 CARRY OUT A VEHICLE INSPECTION AND VERIFY THE SELF-TEST PROCEDURE NOTE: If the self-test or communication concern occurred after a failed or an aborted reprogram, the module may be blank. Attempt to reprogram the module again before continuing with this pinpoint test.
- Visually inspect the following for obvious signs of electrical damage:
- harness wiring
- electrical connections
- Verify the correct procedure was used to activate the self-test for the scan tool. Refer to SCAN TOOL SETUP AND FUNCTIONALITY .
Was the correct self-test procedure used?
Yes No GO to QA2. REFER to SCAN TOOL SETUP AND FUNCTIONALITY . - Visually inspect the following for obvious signs of electrical damage:
- QA2 CARRY OUT THE NETWORK TEST NOTE: When using Integrated Diagnostic System (IDS), the scan tool attempts to communicate with the PCM first. After establishing communication with the PCM, the scan tool then attempts to communicate with all modules on the vehicle. If an IDS session cannot be established, IDS may state no communication can be established with the PCM:
- choose No when the scan tool prompts whether or not to retry communication.
- enter a PCM part number, tear tag or calibration number to identify the vehicle and start a session. The PCM part number and 4-character tear tag are located on the PCM.
- Ignition ON, engine OFF.
- Carry out the network test.
Do all modules indicate pass?
Yes No For DTC U0101, GO to QA8.
For DTCs U0121 or U1039, GO to QA9.
For DTC U0155, GO to QA10.
For all others, REFER to SYMPTOM CHARTS , GO to PINPOINT TEST QT .If only PCM indicates fail, GO to QA3.
For network test or all other modules indicates fail, REFER to the appropriate Module Communications Network article to diagnose The Powertrain Control Module (PCM) Does Not Respond To The Scan Tool Or No High Speed Controller Area Network (HS-CAN) Communication Symptom. - QA3 CHECK FOR VREF VOLTAGE AT A SENSOR
- Ignition ON, engine OFF.
- For electronic throttle control (ETC) applications,
- ETBTPS connector disconnected.
- Measure the voltage between:
(+) ETBTPS Connector, Harness Side (-) ETBTPS Connector, Harness Side ETCREF ETCRTN - For all others,
- TP Sensor connector disconnected.
- Measure the voltage between:
(+) TP Sensor Connector, Harness Side (-) TP Sensor Connector, Harness Side VREF SIGRTN
Is the voltage between 4.5 - 5.5 V?
Yes No REFER to the appropriate Module Communications Network article to diagnose The Powertrain Control Module (PCM) Does Not Respond To The Scan Tool Or No High Speed Controller Area Network (HS-CAN) Communication Symptom. For Crown Victoria,
Grand Marquis,
Ranger, and
Town Car, GO to QA6.
For all others, GO to QA4. - QA4 CHECK THE ISP-R VOLTAGE AT THE PCM HARNESS CONNECTOR
- Ignition OFF.
- PCM connector disconnected.
- Ignition ON, engine OFF.
- Measure the voltage between:
(+) PCM Connector, Harness Side (-) ISP-R Ground
Is the voltage greater than 10 V?
Yes No GO to QA5. REPAIR the open circuit. CLEAR the DTCs. REPEAT the self-test. - QA5 CHECK THE PCM VPWR CIRCUITS FOR VOLTAGE
- Ignition OFF.
- Disconnect the PCM.
- Connect a 5 amp fused jumper wire between the following:
Point A PCM Connector, Harness Side Point B PCMRC Ground - Ignition ON, engine OFF.
- Measure the voltage between:
(+) PCM Connector, Harness Side (-) VPWR Ground
Are the voltages greater than 10 V?
Yes No GO to QA7. GO to PINPOINT TEST B . - QA6 CHECK THE PCM VPWR CIRCUITS FOR VOLTAGE
- Ignition OFF.
- Disconnect the PCM.
- Ignition ON, engine OFF.
- Measure the voltage between:
(+) PCM Connector, Harness Side (-) VPWR Ground
Is the voltage greater than 10 V?
Yes No GO to QA7. GO to PINPOINT TEST B . - QA7 CHECK THE PCM GROUND CIRCUITS FOR AN OPEN
Are the resistances less than 5 ohms?
Yes No GO to QA11. REPAIR the open circuit. CLEAR the DTCs. REPEAT the self-test. - QA8 DTC U0101: CHECK FOR A TRANSAXLE/TRANSMISSION CONTROL MODULE (TCM) CONCERN
- Check for any TCM DTCs.
- Check for other TCM related symptoms.
Are any concerns present?
Yes No REFER to the appropriate Automatic Transaxle/Transmission to continue diagnosis of TCM related symptoms or DTCs. GO to QA11. - QA9 DTCS U0121 AND U1039: CHECK FOR AN ANTI-LOCK BRAKE SYSTEM (ABS) MODULE CONCERN
- Check for any ABS module DTCs.
- Check for other ABS module related symptoms.
Are any concerns present?
Yes No REFER to the appropriate Vehicle Dynamic Systems article to continue diagnosis of ABS module related symptoms or DTCs. GO to QA11. - QA10 DTC U0155: CHECK FOR AN INSTRUMENT CLUSTER (IC) OR INSTRUMENT PANEL CLUSTER (IPC) CONCERN
- Check for any IC or IPC DTCs.
- Check for other IC or IPC module related symptoms.
Are any concerns present?
Yes No REFER to the appropriate Instrument Cluster article to continue diagnosis of IC or IPC related symptoms or DTCs. GO to QA11. - QA11 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 network test and verify the concern is still present.
- 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) , Programming the VID Block for a Replacement PCM. The system is operating correctly at this time. The concern may have been caused by a loose or corroded connector.