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

WARNING: This page is about a different car, the 2010 Mercury Milan, 2010 Lincoln MKZ, and 2010 Ford Fusion. 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 LH 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, ACCM (Hybrid only), Accessory Protocol Interface Module (APIM), Battery Energy Control Module (BECM) (Hybrid only), DC/DC (Hybrid only), Headlamp Control Module (HCM), Instrument Panel Cluster (IPC), Power Steering Control Module (PSCM), Restraints Control Module (RCM), Occupant Classification System Module (OCSM), PCM or Transmission Control Module (TCM)?
- Yes : If "pass" or a DTC was listed next to the PCM, a network fault is not currently present. Go To PINPOINT TEST AE 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 AD to diagnose no HS-CAN communication.
A2 VERIFY THE PC/ED MANUAL PINPOINT TEST QA HAS BEEN CARRIED OUT
- Verify that the Powertrain Control/Emissions Diagnosis (PC/ED) manual 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 DLC C251-6, circuit VDB04 (WH/BU), harness side and the DLC C251-14, circuit VDB05 (WH), harness side.
  
  Fig 1: Checking HS-CAN Termination Resistance
  Courtesy of FORD MOTOR CO.
- Is the resistance between 54 and 66 ohms?
- Yes : CONNECT the negative battery cable. GO to A7.
- No : For 2.5L gasoline and 3.0L engines, GO to A4.
  For 3.5L engine, GO to A5.
  
  For 2.5L hybrid engine, GO to A6.
A4 CHECK THE HS-CAN CIRCUITS BETWEEN THE PCM AND THE DLC FOR AN OPEN - 2.5L GAS AND 3.0L
- Disconnect: PCM C175b.
- Measure the resistance between the PCM C175b-59, circuit VDB04 (WH/BU), harness side and the DLC C251-6, circuit VDB04 (WH/BU), harness side.
  
  Fig 2: Measuring Resistance Between PCM C175b-59, Circuit VDB04 (WH/BU) And DLC C251-6, Circuit VDB04 (WH/BU), Harness Side
  Courtesy of FORD MOTOR CO.
- Measure the resistance between the PCM C175b-58, circuit VDB05 (WH), harness side and the DLC C251-14, circuit VDB05 (WH), harness side.
  
  Fig 3: Measuring Resistance Between PCM C175b-58, Circuit VDB05 (WH) And DLC C251-14, Circuit VDB05 (WH), Harness Side
  Courtesy of FORD MOTOR CO.
- Are the resistances less than 5 ohms?
  - Yes : CONNECT the negative battery cable. GO to A7.
  - No : REPAIR the circuit in question. CONNECT the negative battery cable. CLEAR the DTCs. REPEAT the network test with the scan tool.
A5 CHECK THE HS-CAN CIRCUITS BETWEEN THE PCM AND THE DLC FOR AN OPEN - 3.5L
- 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 4: Measuring Resistance Between PCM C175b-2, Circuit VDB04 (WH/BU) And DLC C251-6, Circuit VDB04 (WH/BU), Harness Side
  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 5: Measuring Resistance Between PCM C175b-3, Circuit VDB05 (WH) And DLC C251-14, Circuit VDB05 (WH), Harness Side
  Courtesy of FORD MOTOR CO.
- Are the resistances less than 5 ohms?
- Yes : CONNECT the negative battery cable. GO to A7.
- No : REPAIR the circuit in question. CONNECT the negative battery cable. CLEAR the DTCs. REPEAT the network test with the scan tool.
A6 CHECK THE HS-CAN CIRCUITS BETWEEN THE PCM AND THE DLC FOR AN OPEN - 2.5L HYBRID
- Disconnect: PCM C175b.
- Measure the resistance between the PCM C175b-59, circuit VDB04 (WH/BU), harness side and the DLC C251-6, circuit VDB04 (WH/BU), harness side.
  
  Fig 6: Measuring Resistance Between PCM C175b-59, Circuit VDB04 (WH/BU) And DLC C251-6, Circuit VDB04 (WH/BU), Harness Side
  Courtesy of FORD MOTOR CO.
- Measure the resistance between the PCM C175b-43, circuit VDB05 (WH), harness side and the DLC C251-14, circuit VDB05 (WH), harness side.
  
  Fig 7: Measuring Resistance Between PCM C175b-43, Circuit VDB05 (WH) And DLC C251-14, Circuit VDB05 (WH), Harness Side
  Courtesy of FORD MOTOR CO.
- Are the resistances less than 5 ohms?
- Yes : CONNECT the negative battery cable. GO to A7.
- No : REPAIR the circuit in question. CONNECT the negative battery cable. CLEAR the DTCs. REPEAT the network test with the scan tool.
A7 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 - 2.5L , ELECTRONIC ENGINE CONTROLS - 3.0L (4V) or ELECTRONIC ENGINE CONTROLS - 3.5L . 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.