Pin 51 (pink wire) coming out of the pcm has 12 volts with ignition in the run position

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Question answer by Jeff Armer, our Automotive Electronics Tech.

Jeff Armer Mar 30, 2024
Under the hood in the engine compartment .And it's called a PCM - powertrain control module.
Powertrain Control Module (PCM)
At the left front side of the engine compartment
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Powertrain Control Module Connector End Views
Connector 1: Powertrain Control Module (PCM) C1
Connector 2: Powertrain Control Module (PCM) C2

Powertrain Control Module (PCM) C1



Connector Part Information
OEM: 12191110
Service: 12167308
Description: 80-Way F Micro-Pack 100W Sealed (BU)

Terminal Part Information
Pins: 1- 7, 11, 12, 14, 15, 19-21, 23-30, 33, 36, 37, 39, 40, 43-, 48, 51, 54, 57, 58, 61, 63-70, 73-77, 80
Terminal/Tray: See Terminal Repair Kit
Core/Insulation Crimp: See Terminal Repair Kit
Release Tool/Test Probe: See Terminal Repair Kit

Powertrain Control Module (PCM) C1 Pin
Wire Color
Circuit No.
Function

1
BK/WH
451
Ground

2
L-GN
1867
12-Volt Reference

3
PK/BK
1746
Fuel Injector 3 Control

4
L-GN/BK
1745
Fuel Injector 2 Control

5-6
--
--
Not Used

7
GY
2705
5-Volt Reference

8-10
--
--
Not Used

11
L-BU
1876
KS 2 Signal

12
D-BU/WH
1869
CKP Sensor Signal

13
--
--
Not Used

14
OG/BK
1061
UART Serial Data

15
D-BU/WH
774
UART Serial Data

16-18
--
--
Not Used

19
PK
439
Ignition 1 Voltage

20
OG
440
Battery Positive Voltage

21
YE/BK
1868
Low Reference

22
--
--
Not Used

23
BK
470
Low Reference

24
BK/WH
451
Ground (NC1/NC8)

25
TN
1671
HO2S Low Signal Bank 2 Sensor 2 (NC1/NC8)

26
TN
1667
HO2S Low Signal Bank 2 Sensor 1

27
BK/WH
451
Ground (NC1/NC8)

28
TN/WH
1669
HO2S Low Signal Bank 1 Sensor 2 (NC1/NC8)

29
TN
1664
HO2S Low Signal Bank 1 Sensor 1

30
L-GN
1478
Coolant Level Switch Signal

31-32
--
--
Not Used

33
PU
420
TCC Brake Switch/Cruise Control Release Signal

34-35
--
--
Not Used

36
BK
1744
Fuel Injector 1 Control

37
YE/BK
846
Fuel Injector 6 Control

38
--
--
Not Used

39
YE/BK
625
Starter Enable Relay Control

40
BK/WH
451
Ground

41-42
--
--
Not Used

43
RD/BK
877
Fuel Injector 7 Control

44
L-BU/BK
844
Fuel Injector 4 Control

45
GY
2700
5-Volt Reference

46
GY
474
5-Volt Reference

47
--
--
Not Used

48
GY
597
5-Volt Reference

49-50
--
--
Not Used

51
D-BU
496
KS 1 Signal

52-53
--
--
Not Used

54
OG/BK
469
Low Reference

55-56
--
--
Not Used

57
OG
440
Battery Positive Voltage

58
D-GN
1049
Class 2 Serial Data

59-60
--
--
Not Used

61
PK/BK
632
Low Reference

62
--
--
Not Used

63
BK
2755
Low Reference

64
BK/WH
451
Ground

65
PU
1670
HO2S High Signal Bank 2 Sensor 2 (NC1/NC8)

66
PU
1666
HO2S High Signal Bank 2 Sensor 1

67
BK/WH
451
Ground

68
PU/WH
1668
HO2S High Signal Bank 1 Sensor 2 (NC1/NC8)

69
PU/WH
1665
HO2S High Signal Bank 1 Sensor 1

70
BN
1174
Oil Level Switch Signal

71-72
--
--
Not Used

73
BN/WH
633
CMP Sensor Signal

74
YE
410
ECT Sensor Signal

75
PK
1020
Ignition 0 Voltage

76
BK/WH
845
Fuel Injector 5 Control

77
D-BU/WH
878
Fuel Injector 8 Control

78-79
--
--
Not Used

80
BK
407
Low Reference


Powertrain Control Module (PCM) C2



Connector Part Information
OEM: 12191110
Service: 12167308
Description: 80-Way F Micro-Pack 100W Sealed (GN)

Terminal Part Information
Terminal/Tray: See Terminal Repair Kit
Core/Insulation Crimp: See Terminal Repair Kit
Release Tool/Test Probe: See Terminal Repair Kit

Powertrain Control Module (PCM) C2 Pin
Wire Color
Circuit No.
Function

1
BK/WH
451
Ground

2
--
--
Not Used

3
TN
1465
Fuel Pump Relay Control - Secondary

4-8
--
--
Not Used

9
D-GN/WH
465
Fuel Pump Relay Control

10
WH
121
Engine Speed Signal

11-13
--
--
Not Used

14
RD/BK
380
A/C Refrigerant Pressure Sensor Signal

15
BN
25
Charge Indicator Control

16
GY/BK
1694
4WD Low Signal

17-19
--
--
Not Used

20
L-GN/BK
822
VSS Low Signal

21
PU/WH
821
VSS High Signal

22-24
--
--
Not Used

25
TN
472
IAT Sensor Signal

26
PU
2121
IC 1 Control

27
RD
2127
IC 7 Control

28
L-BU/WH
2126
IC 6 Control

29
D-GN/WH
2124
IC 4 Control

30
--
--
Not Used

31
YE
492
MAF Sensor Signal

32
L-GN
432
MAP Sensor Signal

33
--
--
Not Used

34
D-GN/WH
428
EVAP Canister Purge Solenoid Control

35-38
--
--
Not Used

39
RD
631
12-Volt Reference

40
BK/WH
451
Ground

41-42
--
--
Not Used

43
D-GN/WH
459
A/C Compressor Clutch Relay Control

44
--
--
Not Used

45
WH
1310
EVAP Canister Vent Solenoid Control

46
BN/WH
419
MIL Control

47-48
--
--
Not Used

49
YE/BK
1827
Vehicle Speed Signal

50
D-GN/WH
817
Vehicle Speed Signal

51
--
--
Not Used

52
BN
2391
HO2S Heater Low Control Bank 1 Sensor 2 (NC1/NC8)

53
RD/WH
3223
HO2S Heater Low Control Bank 2 Sensor 2 (NC1/NC8)

54
PU
1589
Fuel Level Sensor Signal - Primary

55-56
--
--
Not Used

57
BK
552
Low Reference

58
TN/WH
332
Oil Pressure Sensor Signal

59
PU
806
Crank Voltage

60
BN
2129
Low Reference

61
BN/WH
2130
Low Reference

62-63
--
--
Not Used

64
D-GN
890
Fuel Tank Pressure Sensor Signal

65
--
--
Not Used

66
PU/WH
2128
IC 8 Control

67
RD/WH
2122
IC 2 Control

68
D-GN
2125
IC 5 Control

69
L-BU
2123
IC 3 Control

70-71
--
--
Not Used

72
BK/WH
3113
HO2S Heater Low Control Bank 1 Sensor 2 (NC1/NC8)

73
D-BU
1936
Fuel Level Sensor Signal - Secondary

74
L-GN
3212
HO2S Heater Low Control Bank 2 Sensor 1

75
GY
23
Generator Field Duty Cycle Signal

76-79
--
--
Not Used

80
BK
2751
Low Reference

There is no direct connection from the purple wire to the ignition switch . This is computer controlled , Ignition switch is a low voltage input to the BCM - body control module . When you turn the key to start the BCM see's this an sends a message on the serial data network to the PCM / ECM - engine computer . IF the PCM / ECM see's voltage from the Internal mode switch in the transmission it knows it is in park or neutral an see's no problems with the anti- theft system it will energize the crank relay sending Battery voltage on the purple wire to the starter solenoid . You have no clue of the complexity of this system , do yourself a favor an take it to a qualified repair shop . Before you make matters worse . You already spent money on a new starter needlessly .

Circuit Description
Moving the ignition switch to the START position signals the body control module (BCM) through discrete inputs from the ignition transducer that engine crank has been requested. The BCM verifies that theft is not active and sends a serial data message to the engine control module (ECM)/powertrain control module (PCM) requesting engine start. The ECM/PCM receives a 12-volt signal from the park/neutral position (PNP) switch or clutch pedal start switch notifying that it is safe to start the engine. There is a splice on this circuit in the fuse block-underhood that supplies power for the starter relay coil. The starter relay coil control circuit is then grounded by the ECM/PCM closing the switch in the starter relay suppling 12 volts to the S-terminal of the starter. Ground is supplied through the engine block.
Vehicle Theft Deterrent (VTD) Description and Operation
Circuit Description
The Passlock?"¢ system is provided in order to prevent vehicle theft if the ignition lock cylinder is forced to rotate. The Passlock controller reads the coded Passlock?"¢ data signal. The data consists of a voltage generated by a voltage divider network created between the Passlock assembly and the Passlock?"¢ controller. If the data is correct , indicating rotation of the lock cylinder with the proper mechanically cut key, then the Passlock?"¢ controller sends a password to the Powertrain controller over the class 2 bus to indicate that starter engagement should be allowed. The Passlock?"¢ controller also interfaces with the driver displays subsystem to indicate, via a Security telltale, the Passlock?"¢ subsystem's status and acute subsystem failures.
The components of the Passlock?"¢ System are as follows:
?€¢
The ignition switch

?€¢
The body control module (BCM)

?€¢
The security indicator on the instrument cluster

?€¢
The engine control module (ECM)

Security - anti-theft system problem .

Hi mate start at the easiest point which will be to check your EARTH to make sure everything is earthed.

Test procedure:


1. Test powers and grounds at the Powertrain Control Module (PCM) on the C1 connector. Pins 2 and 22 are power, then check pins 31 and 32 for ground.

2. Next, test the 5 volt power supplies at pin 17 of the C1 connector and pin 31 of the C2 or middle connector for shorts to ground. Sensors on the circuit are the Camshaft Position (CMP) sensor, Crankshaft Position (CKP) sensor, Throttle Position Sensor (TPS), Manifold Absolute Pressure (MAP) sensor and Vehicle Speed Sensor (VSS).

3. Unplug the sensors on the 5 volt power supply, one at a time, while monitoring the 5 volt supply.

4. When the shorted sensor is unplugged, the PCM will wake up and scan tool communication will return.

5. The wiring harness could also be shorted to ground on one of the 5 volt power supply wires. Cut the wires at the PCM on pins C1-17 and just unplug the center connector. Then check for the 5 volts on the PCM of the connector or checking for any continuity to ground with the sensors unplugged at the PCM connector on C1-17 and C2-31 to check the wiring harness

Since you have replaced all of the parts, perhaps the problem is the wires. Check continuity of critical wires. Are you getting power to the computer, ignition module and coil? Check continuity of wires from computer to ignition module and crank sensor. Check for bent pins and pushed back female terminals in connectors.

That code is for the ignition control circuit. It is the white wire that runs from Ignition module to the VCM. this controls the timing.

This is either a bad wire/connection from the VCM to the ignition module, ignition module, or VCM. I would check them closely in that order. This can commonly be a bad ditributor

Tests/Procedures:
1. Use an air gap spark tester set at 25-30 KV and check the output from the coil wire and then at multiple spark plug wires.
2. Bring the engine to Top Dead Center (TDC) #1 and verify the rotor is pointing to the 8 that is cast into the distributor housing to make sure it is not out of time.
3. If the distributor is dropped correctly, but spark is erratic at the plugs but good at the coil, replace the distributor cap and rotor with one from the dealer.

Potential Causes:
Distributor Cap
Incorrect Distributor Timing
Ignition Rotor

Tech Tips:
This trouble code can set from extended cranking and is most likely not the cause of the problem as long as there is spark
Tests/Procedures:
1. Using a Digital Volt Ohm Meter (DVOM) or lab scope, check the White wire at the ignition module pin B while cranking. This should be a 0-5 volt square wave pattern any time the engine is cranking or running.
2. If there is more than 5 volts on the White wire at pin B, check the White wire from the Powertrain Control Module (PCM) to the ignition module pin B for shorts to voltage.
3. If the wire checks OK, check powers and grounds to the PCM while cranking. If the powers and grounds are OK at the PCM, the PCM will need to be replaced.

Potential Causes:
Ground Ignition Module Power
Powertrain Control Module (PCM) Wiring
Tech Tips:
Conditions for Setting the DTC The Ignition Control voltage is more than 4.9 volts.


Hope this helps; also keep in mind that your feedback is important and I'll appreciate your time and consideration if you leave some testimonial comment about this answer.

Thank you for using Fixya, and have a nice day

1. Disconnect the voltage regulator connection at the alternator assembly and start the engine to see if it runs better or not and to see if the same coil-on-plug (COP) unit codes reset.

2. If the engine operation is good unless the voltage regulator connection is plugged in, it suggests a diode failure of the alternator assembly creating electrical noise.

3. If the engine operation is not any different with the voltage regulator connection unplugged, check the COP unit circuits at the PCM for battery voltage with the ignition switch in the run position and the COP's connected. Perform a wiggle test of the circuits and harness to verify that battery voltage to the PCM cannot be interrupted indicating a PCM failure.
COP 1 is controlled by a Light Green/White (LG/WH) wire at pin 1 of the C175e connector.
COP 2 is controlled by a Pink/White (PK/WH) wire at pin 12 of the C175e connector.
COP 3 is controlled by a White/Pink (WH/PK) wire at pin 24 of the C175e connector.
COP 4 is controlled by a Dark Green/Violet (DG/VT) wire at pin 35 of the C175e connector.
COP 5 is controlled by a Light Green/Yellow (LG/YE) wire at pin 36 of the C175e connector.
COP 6 is controlled by a Orange/Yellow (OG/YE) wire at pin 22 of the C175e connector. 1. There have been a lot of problems with the coil circuit wires breaking inside their insulation near the Powertrain Control Module (PCM) connector, usually within 2" of the PCM. Wiggle test the wiring harness, starting from the PCM and working toward the coil. 1. Verify battery power is present and consistent on the Red (RD) wire of multiple Coil-On-Plug (COP) unit connections.

2. If the battery power supply to the COPs is good, disconnect and inspect the C133 engine harness connector at the top of the engine for a possible connection issue. This connector is a grey 16-terminal connector. It may be behind the rear side of the intake plenum. Service the connection as necessary.

3. Disconnect the PCM connection and inspect the COP unit primary circuits and terminals at the C175E connection. Service the connection as necessary.

4. If the circuits and connections all appear to be in good condition, replace the PCM. Replacement of the PCM will require a programming function to be performed using the Ford scan tool for Passive Anti-theft System (PATS) functions and the PCM is an 8 year/80,000 mile (7/70 for CA state emissions) warranty item.

Battery Constant 12v+ Positive Wire (+): Black/Orange And Red/White
Battery Constant 12v+ Positive Wire Location: Ignition Switch Harness
Starter Positive Wire (+): Yellow
Starter Positive Wire Location: Ignition Switch Harness
Ignition Positive Wire (+): Blue (16 Gauge)
Ignition Positive Wire Location: Ignition Switch Harness
Second Ignition Positive Wire (+): Yellow/Red
Second Ignition Positive Wire Location: Ignition Switch Harness
Accessory Positive Wire (+): Blue (10 Gauge)
Accessory Positive Wire Location: Ignition Switch Harness
Second Accessory Positive Wire (+): Orange
Second Accessory Positive Wire Location: Ignition Switch Harness
Parking Light Positive Wire (+): Black/Yellow
Parking Light Positive Wire Location: At Headlight Switch
Power Door Lock Positive Wire (+): Orange/Violet
Power Door Lock Positive Wire Location: In Drivers Kick Panel, White 6-Pin
Power Door Unlock Positive Wire (+): Pink/Violet
Power Door Unlock Positive Wire Location: In Drivers Kick Panel, White 12-Pin
Door Trigger Negative Wire (-): Yellow
Door Trigger Negative Wire Location: At Headlight Switch
Domelight Supervision Wire: Use Door Trigger (Requires Relay)
Domelight Supervision Wire Location: N/A
Horn Negative Wire (-): Black/Red
Horn Negative Wire Location: At Steering Column Harness
Tachometer Wire Negative Wire (-): Gray
Tachometer Wire Negative Wire Location: At PCM, Connector 1, Pin A7. The PCM (powertrain control module) is located on the firewall next to the wiper motor.
Brake Light Positive Wire (+): White/Tan
Brake Light Positive Wire Location: At Switch Above Brake Pedal
Factory Alarm Disarm Wire (-): Black/Orange (To disarm requires a (-) negative through a 1565 ohm resistor and an extra relay to connect.)
Factory Alarm Disarm Wire Location: In Drivers Kick Panel, White 12 Pin Plug
Factory Anti-Theft System: N/A
Factory Anti-Theft System Location: N/A

check ignition fuse.if okay.remove one of coils connectors using a test light .turn ignition key to on position .terminal 1 on the connector to coil is the first to left with the locking tab up. then remove the ignition module connector terminal 4 is 12 volt supply.4 terminal to the right with lock tab up.connect test light to ground.take the pointed end touch both the terminals for 12 volts with ignition on position.if getting 12 volts.you have PCM PROBLEMS OR CRANK POSITION SENSOR..IF GETTING NO 12 VOLTS YOU GOT A BLOWN FUSE OR GROUNDING PROBLEMS.