Pinpoint Test A: The Pcm Does Not Respond To The Scan Tool

WARNING: This page is about a different car, the 2010 Lincoln MKX and 2010 Ford Edge. However, it is still accessible from the selected car via links, so may be relevant.

NOTE: Use the correct probe adapter(s) when making measurements. Failure to use the correct probe adapter(s) may damage the connector.

NOTE: Failure to disconnect the battery when instructed will result in false resistance readings. Refer to BATTERY, MOUNTING AND CABLES .

A1 VERIFY WHETHER OTHER HS-CAN MODULES PASS THE NETWORK TEST
- Enter the following diagnostic mode on the scan tool: Network Test.
- In the left hand pane of the IDS network test display screen, verify whether any HS-CAN modules passed the network test.
- Is the text "pass" or a DTC listed next to any of the following modules (if equipped): 4X4 control module, ABS module, Accessory Protocol Interface Module (APIM), Instrument Cluster (IC), Occupant Classification System Module (OCSM), PCM or Restraints Control Module (RCM)?
- Yes: If "pass" or a DTC was listed next to the PCM, a network fault is not currently present. GO to PINPOINT TEST V to diagnose an intermittent HS-CAN fault condition.
  If "pass" or a DTC was listed next to one or more modules other than the PCM, GO to A2 .
- No: No modules are currently communicating on the HS-CAN . GO to PINPOINT TEST W to diagnose no HS-CAN communication.
A2 PC/ED MANUAL PINPOINT TEST QA VERIFICATION CHECK
- Verify that pinpoint test QA has been carried out.
- Has pinpoint test QA been carried out?
- Yes: GO to A3 .
- No: REFER to the INTRODUCTION - GASOLINE MODELS , pinpoint test QA to diagnose no communication with the PCM.
A3 CHECK THE HS-CAN TERMINATION RESISTANCE
- Ignition OFF.
- Disconnect: Negative Battery Cable.
- Measure the resistance between the Data Link Connector (DLC) C251-6, circuit VDB04 (WH/BU), harness side and the DLC C251-14, circuit VDB05 (WH), harness side.
  
  Fig 1: Measuring Resistance Between Data Link Connector (DLC) C251-6, Circuit VDB04 (WH/BU) And DLC C251-14, Circuit VDB05 (WH)
  Courtesy of FORD MOTOR CO.
- Is the resistance between 54 and 66 ohms?
- Yes: CONNECT the negative battery cable. GO to A5.
- No: GO to A4 .
A4 CHECK THE HS-CAN CIRCUITS BETWEEN THE PCM AND THE DLC FOR AN OPEN
- Disconnect: PCM C175b.
- Measure the resistance between the PCM C175b-2, circuit VDB04 (WH/BU), harness side and the DLC C251-6, circuit VDB04 (WH/BU), harness side.
  
  Fig 2: Measuring Resistance Between PCM C175B-2, Circuit VDB04 (WH/BU) And DLC C251-6, Circuit VDB04 (WH/BU)
  Courtesy of FORD MOTOR CO.
- Measure the resistance between the PCM C175b-3, circuit VDB05 (WH), harness side and the DLC C251-14, circuit VDB05 (WH), harness side.
  
  Fig 3: Measuring Resistance Between PCM C175B-3, Circuit VDB05 (WH) And DLC C251-14, Circuit VDB05 (WH)
  Courtesy of FORD MOTOR CO.
- Are the resistances less than 5 ohms?
- Yes: CONNECT the negative battery cable. GO to A5 .
- No: REPAIR the circuit in question. CONNECT the negative battery cable. CLEAR the DTCs. REPEAT the network test with the scan tool.
A5 CHECK FOR CORRECT PCM OPERATION
- Disconnect all the PCM connectors.
- Check for:
  - corrosion
  - damaged pins
  - pushed-out pins
- Connect all the PCM connectors and make sure they seat correctly.
- Operate the system and verify the concern is still present.
- Is the concern still present?
- Yes: INSTALL a new PCM. REFER to ELECTRONIC ENGINE CONTROLS CLEAR the DTCs. REPEAT the network test with the scan tool.
- No: The system is operating correctly at this time. The concern may have been caused by a loose or corroded connector. CLEAR the DTCs. REPEAT the network test with the scan tool.