Brake controller not communicating w/ 7 pin connector

C1440 Pressure Transducer Input Circuit Failure YES
C1440 (ABS only) Pressure Transducer Input Circuit Failure ABS Module Go To Pinpoint Test P .
Normal Operation The brake pressure switch provides an additional speed control deactivation if the brake pedal position (BPP) switch fails. When the brake pedal is pressed, 1700 kPa (246 psi) of brake fluid pressure in the brake master cylinder opens the brake pressure switch, removing B+ voltage to the speed control servo electric clutch.

Possible Causes
• circuit 10 (LG) open
• circuit 307 (BK/YE) open, short to power
• ABS module
• brake pressure switch
• speed control deactivator switch

PINPOINT TEST P: DTC C1440 (ABS ONLY) - PRESSURE TRANSDUCER SIGNAL FAULT CAUTION: Use the flex probe kit for all test connections to prevent damage to the wiring terminals. Do not use standard multimeter probes.
Test Step Result / Action to Take P1 VERIFY THE DTC

• Connect the diagnostic tool.
• Key in ON position.
• Clear DTC C1440. Road test the vehicle. Repeat the self-test.
• Does DTC C1440 repeat?

Yes
GO to P2 .

No
The system is OK at this time. P2 MONITOR THE BRAKE PRESSURE SWITCH PID FOR CLOSED POSITION

• Enter the following diagnostic mode on the diagnostic tool: ABS Module PID.
• Monitor the powertrain control module (PCM) brake pressure switch PID.
• With foot off the brake pedal, does the PID read closed?

Yes
GO to P3 .

No
GO to P4 . P3 MONITOR THE BRAKE PRESSURE SWITCH PID FOR OPEN POSITION

• Enter the following diagnostic mode on the diagnostic tool: ABS Module PID.
• Monitor the PCM brake pressure switch PID.
• While pressing the brake pedal, does the PID read open?

Yes
GO to P9

No
GO to P7 . P4 CHECK THE CIRCUIT 10 (LG/RD) FOR AN OPEN

• Key in OFF position.
• Disconnect: Speed Control Deactivator Switch C1025.
• Key in ON position.
• Measure the voltage between the brake pressure switch C1025-2, circuit 10 (LG/RD), harness side and ground.
• Is the voltage greater than 10 volts?

Yes
GO to P5 .

No
REPAIR the circuit. CLEAR the DTCs and REPEAT the self-test. P5 CHECK THE BRAKE PRESSURE SWITCH

• Key in OFF position.
• Measure the resistance across the brake pressure switch pins, component side.
• Is the resistance less than 5 ohms?

Yes
GO to P6 .

No
INSTALL a new speed control deactivator switch. REFER to Section 310-03 . CLEAR the DTCs. REPEAT the self-test. P6 CHECK CIRCUIT 307 (BK/YE) FOR AN OPEN

• Connect: Speed Control Deactivator Switch C1025.
• Disconnect: ABS Module C155.
• Measure the voltage between the ABS module C155-40, circuit 307 (BK/YE). harness side and ground.
• Is the voltage greater than 10 volts?

Yes
GO to P9

No
REPAIR the circuit. CLEAR the DTCs. REPEAT the self-test. P7 CHECK CIRCUIT 307 (BK/YE) FOR A SHORT TO POWER

• Key in OFF position.
• Disconnect: Brake Pressure Switch C1025.
• Key in ON position.
• Measure the voltage between the ABS module C155-40, circuit 307 (BK/YE), harness side and ground.
• Is any voltage present?

Yes
REPAIR the circuit. CLEAR the DTCs. REPEAT the self-test.

No
GO to P8 . P8 CHECK BRAKE PRESSURE SWITCH

• Start the engine.
• Measure the resistance between the brake pressure switch C1025 pin 1, component side and the brake pressure switch C1025 pin 2, component side while firmly pressing the brake pedal.
• Is the resistance greater than 10,000 ohms?

Yes
GO to P9 .

No
INSTALL a new speed control deactivator switch. REFER to Section 310-03 . CLEAR the DTCs. REPEAT the self-test. P9 CHECK FOR CORRECT ABS MODULE OPERATION

• Disconnect all ABS connectors.
• Check for:
  • corrosion
  • pushed-out pins
• Connect all ABS 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 ABS module. REFER to Anti-Lock Brake System (ABS) Module in this section. TEST the system for normal operation.

No
The system is operating correctly at this time. Concern may have been caused by a loose or corroded connector. CLEAR the DTCs. REPEAT the self-test.

Loss of communication with brake control module is exactly what it says. There is a problem with the wiring harness that goes to the ABS controller. You might make sure it is plugged all of the way in. You might also unplug it and make sure there is no corrosion or damages pins in the connector.

Hi Donald,
It sounds like a wiring issue. Double the wiring to your connector on the vehicle. Also check the wiring on the trailer connector. I have seen many trailer that are wired to ground through the ******, this of course will cause an intermittent ground and flickering lights. you only need four (4) wires... One for a ground, One for running lights, and Two wires for brake and turn - one wire for the left and one wire for the right. You can also find the proper pin wiring for vehicle and trailer on the internet. Cheers. I hope this helps. John

Hello,
The same fuse that feeds the high mount brake light feeds the brake control. Should be in the side panel on the drivers side.

Regards, Tony

It sounds like someone messed up to me! Apparently, the brake controller got wired into an ignition circuit that it should not have gotten wired to. When accessories are added to a vehicle, it is extremely important that the vehicle wiring diagrams are used so that you know EXACTLY what you are tying into. Some of the Chevy trucks that are sold with trailer towing packages already have the wiring for brake controllers under the dash. This makes installation easy and is already tied into the correct things.

Also see my comments on related subjects HERE

It is a generic Nissan brake light switch replacement procedure... the brake light switch on a Nissan Altima i.e. controls the illumination of the brake lights. Without the switch, the lights would not go on. The switch has no service life, so when it goes, it usually happens suddenly. New brake light switches can be obtained from Nissan or from a Nissan dealership.

1. Remove the cotter pin from the pin bolt that holds the brake pedal to the brake booster with a pair of pliers. There is a small cotter pin running through the brake pedal to brake booster connection. You need to pull this cotter pin out to remove the larger pin that holds the brake pedal to the brake booster.
2. Slide the pin out of the brake booster mounting bracket.
3. Pull up on the brake pedal to slide it out of the brake booster mounting bracket.
4. Remove the bolts holding the brake switch to the firewall using a socket wrench.
5. Remove the electrical connector on the brake switch by pulling it straight off the switch.
6. Slide the switch off the firewall.
7. Install the new switch. Installation is the reverse of removal. Make sure that you replace the cotter pin in the brake booster to brake pedal connection. The cotter pin prevents the retaining pin in the brake booster mounting bracket from coming off.

Hope helps (remember to rate this answer).

How have you tested this? If you are just looking for the stop or brake light, you need to test by pressing the break and probing the same pin as the turn signals as the vehicle does not have separate brake and turn signals. However, If the problem is that you have no signal for the electric brakes on your trailer. You must have a brake controller installed. If there is one installed probe the blue wire coming out the back end of it and press the brake to be sure there is brake output. It is possible for a controller to go bad, and not output anymore.
I wrote an imformative article on diagnosing wiring problems. Click here to read.

Stop Lamp Switch Removal & Installation To Remove:

1. Disconnect battery negative cable.
2. Disarm the air bag system.
   
   
3. Using snap ring pliers, remove pushrod retainer from brake pedal pin.
4. Remove stop lamp switch from pushrod.
5. Disconnect stop lamp switch electrical connector.

To Install:

1. Connect stop lamp switch electrical connector.
2. Snap stop lamp switch onto pushrod.
3. Using an 11 mm socket, push pushrod retainer clip onto brake pedal pin.
4. Connect battery negative cable.
5. Arm the air bag system.

Suspect 7 pin connector problem , you should have power on the 8pm positioned and the centre pin position as you look into the socket (on vehicle. These pins are both male pins as you look at them . If ok check trailer wiring where it splits for either lamp assy ! Good luck

you should not have voltage unless you apply the brakes on the vehicle or the brake controller. the only constant voltage you should have is the charge line on the 7-way.