Question about Buick Regal

2 Answers

I plugged in all three relays to control the cooling fan, vehicle continues to shut off. I connected my OTC nemisys and pulled body code V1255. At this point I have no idea of whhat my next step should be.

Posted by on

  • ectyler3 Mar 20, 2011

    Code V1255- Class 2 communication malfunction. I changed my PCM in December, since I changed that I have noticed that my cooling fans aren't working. Each time I change the cooling fan relays the vehicle shuts off. I have a digital heater control box and it works periodically as well. I do understand that the symptoms may not be related but by me changing the vehicles computer recently sort of makes me think it may need reflashing. I appreciate any assisstance

  • ectyler3 Mar 20, 2011

    I responded to your post by clicking the reply buttom

×

2 Answers

  • Level 3:

    An expert who has achieved level 3 by getting 1000 points

    Superstar:

    An expert that got 20 achievements.

    All-Star:

    An expert that got 10 achievements.

    MVP:

    An expert that got 5 achievements.

  • Master
  • 10,319 Answers

V1255 is set when the control module does not receive a message that it was expecting from another control module, and does not know which control module did not send that message.

Posted on Mar 21, 2011

  • Level 3:

    An expert who has achieved level 3 by getting 1000 points

    All-Star:

    An expert that got 10 achievements.

    MVP:

    An expert that got 5 achievements.

    Vice President:

    An expert whose answer got voted for 100 times.

  • Master
  • 783 Answers

Hello. What is code V1255 mean? I can look it up faster if you can tell me. When did this start happening, what have you done so far, Please give me all the details so i can diagnose and help since i cant be right there to physically see for myself. Thank you.
FixYa Premuim Support Derek

Posted on Mar 20, 2011

1 Suggested Answer

6ya6ya
  • 2 Answers

SOURCE: I have freestanding Series 8 dishwasher. Lately during the filling cycle water hammer is occurring. How can this be resolved

Hi,
a 6ya expert can help you resolve that issue over the phone in a minute or two.
best thing about this new service is that you are never placed on hold and get to talk to real repairmen in the US.
the service is completely free and covers almost anything you can think of (from cars to computers, handyman, and even drones).
click here to download the app (for users in the US for now) and get all the help you need.
goodluck!

Posted on Jan 02, 2017

Add Your Answer

Uploading: 0%

my-video-file.mp4

Complete. Click "Add" to insert your video. Add

×

Loading...
Loading...

Related Questions:

1 Answer

1995 Lt1 Camaro cooling fans operate like this; Cooling fans (2 fans) come on 30 seconds after start up on high, stay on while driving, and turn off when brakes are applied. Stock car, no mods.


Did you have it checked for DTC'S - diagnostic trouble codes ? The cooling fans are controlled by the PCM - engine computer , with the use of three relays ,located in the under hood electrical center . Do you know how to do electrical testing ?
Relay Driven Dual Cooling Fan Diagnostics Looking at wiring diagrams i don't see any connection between the brakes an cooling fans . Checking for DTC'S an doing electrical testing of control circuits from the PCM , Power circuits from the fuse / relay box . Checking grounds an pulling relays ,check for corrosion .

Electric Testing Techniques You Need to Know

View wiring diagrams here http://www.bbbind.com/free_tsb.html

ECM Inputs and Outputs Diagnosis


Mar 30, 2017 | Cars & Trucks

1 Answer

Wiring for cooling system ford escort zetec 1996 1.6i


Wiring for cooling system ? You mean cooling fans ? 1.6 ? This vehicle has 1.8 L or 1.9 L . This cooling system has two electric cooling fans . Three relays , cooling fan power relay , cooling fan hi speed relay an the low speed cooling fan relay. The powertrain control module controls these relays. Go here http://bbbind.com/free_tsb.html free wiring diagrams .

May 15, 2016 | Ford Cars & Trucks

2 Answers

What does this mean?????????????


P0480 Cooling Fan Relay 1 Control Circuit OBD-II Trouble Code Technical Description Article by
don.jpg
Don Bowman
ASE Certified Automotive Tech

Cooling Fan Relay 1 Control Circuit
What does that mean? This is a generic powertrain diagnostic trouble code (DTC), which means it covers all makes/models, 1996-newer. However, specific troubleshooting steps will vary depending on the vehicle.
If your vehicle's check engine light comes on and after pulling the code you find a P0480 displayed, if refers to the engine cooling fan circuit. It is a generic code applying to all OBD II (on board diagnostics) vehicles.
While you are driving, air in sufficient quantity is passing through the radiator effectively cooling the engine. When you bring the car to a stop no air is passing through the radiator and the engine begins to increase in temperature.
The PCM (powertrain control module) senses the increase in engine temperature through the CTS (coolant temperature sensor) located near the thermostat. When the temperature reaches about 223-degrees F (value depends on make/model/engine), the PCM will command the cooling fan relay to turn on the fan. It does so by supplying the ground to the relay.
There is a problem within this circuit causing the fan to fail to operate allowing the engine to overheat while sitting still or driving at a slow speed. When the PCM attempts to activate the fan and senses the command and the result do not match, the code is set.
NOTE: P0480 speaks of the basic circuit, however codes P0481, and P0482 relate to the same problem with the only difference is they relate to the different fan speed relays.
Symptoms Symptoms may include:

  • Check engine light (malfunction indicator lamp) illumination and code P0480 set
  • Engine temperature will rise when the vehicle stops and idles
Potential Causes The causes for this DTC may include:
  • Faulty fan control relay 1
  • Fan control relay harness is open or shorted
  • Circuit electrical connections poor
  • Faulty cooling fan 1
  • Faulty coolant temperature sensor
  • Fan cooling fan harness is open or shorted
  • Cooling fan circuit poor electrical connection
  • Intake air temperature (IAT) failure
  • A/C selector switch
  • A/C refrigerant pressure sensor
  • Vehicle speed sensor (VSS)
Diagnostic and Repair Procedures It is always a wise idea to look up the technical service bulletins (TSB) on your particular vehicle to see what type complaints have been coming in to the dealer service department related to this code. Search using your favorite search engine "technical service bulletins for ....." Look up the code and the type of manufacturer recommended repair. This is also a good idea before buying a vehicle.
Many vehicles will have two engine fans, one for engine cooling and the second for cooling the air conditioning condenser, and additional cooling for the engine.
The fan that is not in front of the air conditioning condenser is the main cooling fan and the one to concentrate on initially. Additionally, many vehicles have multi-speed fans requiring as many as three fan speed relays for low, medium and high.
Open the hood and do a visual inspection. Look at the fan and make sure there is no obstruction in front of the radiator blocking airflow. Spin the fan with your finger (make sure the vehicle and key is off). If it will not spin the fan bearings are shot and the fan is bad.
Check the electrical connection at the fan. Pull the connector apart and look for corrosion or bent pins. Repair if necessary and use dielectric grease on the terminals.
Open the fuse block and inspect the cooling fan relay fuses. If they are good pull the cooling fan relays out. The bottom of the fuse block lid will usually indicate placement, but if not, look in the owner's manual.
The vehicle's PCM's function is to act as a ground to operate components, not to supply power. The fan relays are nothing but a remote light switch. The fan as well as other apparatus draws too much amperage to be safe in the cockpit, so it's kept under the hood.
A constant power supply from the battery is present on a terminal in each of the relays. This one turns on the fan when the circuit is closed. A switched terminal will be hot only when the key is on. The negative terminal in this circuit is the one used when the PCM wishes to active the relay by grounding it.
Look at the circuit diagram displayed on the side of the relay. Look for the simple open and shut circuit. Verify the battery positive terminal in the relay block with constant power. The opposite side goes to the fan. Use a test light to find the hot terminal.
Jump the battery terminal to the fan harness terminal and the fan will operate. If not, disconnect the fan connection at the fan and using an ohmmeter check the continuity between the fan side of the relay terminal and the connector at the fan, If there is continuity the fan is bad. If not the harness between the fuse block and the fan is faulty.
If the fan operated, check the relays. Look at the side of the relay for the switched power terminal or just turn the key on. Check the terminals for an additional power terminal and look where it would be on the relay.
Jump the battery plus terminal in the first test with this switched terminal and place an additional jumper from the negative terminal on the relay to ground. The switch will click on. Use an ohmmeter to test that the constant battery terminal and the fan harness terminal have continuity meaning the circuit has closed.
If the circuit has not closed or the relay has not clicked, the relay is bad. Check all the relays in the same fashion to be sure they are all working.
If there was no switched power at the relay, the ignition switch is suspect.
If they prove to be good, check the CTS with an ohmmeter. Pull the connector off. Let the engine cool and put the ohmmeter on the 200,000 scale. Probe the sensor terminals.
The reading will be about 2.5. For precise readings consult a service manual. Accuracy isn't necessary since all sensors may be different. You just want to know if it's working. Reconnect it and warm the engine.
Shut the engine down and pull the CTS plug again. Check it with the ohmmeter, there should be a big change in resistance, if not the sensor is bad.
If the above procedure could not find a failure, the probability is that a poor connection to the PCM or the PCM itself is at fault. Do not go any farther without consulting your service manual. Disconnecting the PCM could cause loss of programming and the vehicle may not start unless towed to the dealer for reprogramming.

Sep 23, 2015 | 2006 Volkswagen Jetta

1 Answer

I have an 05rendezvous,need to locate switches for cooling system,fans aren't co ming on & now I'm going to need a new radiator,cuz plastic broke.But it broke before fans gave out.Which I changed stat


The engine cooling fan system is controlled by the body control module (BCM) and the powertrain control module (PCM) or engine control module (ECM). The BCM performs the calculations as to how long, when and what speed the cooling fans should turn on. The BCM then sends a class 2 message to the PCM/ECM to engage the cooling fan relays. If there is a malfunction with the BCM, the PCM/ECM will control the engine cooling fans independently. The engine cooling system consists of 2 electrical cooling fans and 3 fan relays. The relays are arranged in a series/parallel configuration that allows the PCM/ECM to operate both fans together at low or high speeds. The cooling fans and fan relays receive battery positive voltage from the underhood accessory wiring junction block. The ground path is provided at G100.
During low speed operation, the PCM/ECM supplies the ground path for the low speed fan relay through the low speed cooling fan relay control circuit. This energizes the cooling fan 1 relay coil, closes the relay contacts, and supplies battery positive voltage from the cool fan 1 fuse through the cooling fan motor supply voltage circuit to the left cooling fan. The ground path for the left cooling fan is through the cooling fan 2 relay and the right cooling fan. The result is a series circuit with both fans running at low speed.
During high speed operation the PCM/ECM supplies the ground path for the cooling fan 1 relay through the low speed cooling fan relay control circuit. After a 3 second delay, the PCM/ECM supplies a ground path for the cooling fan 3 or S/P relay and the cooling fan 2 relay through the high speed cooling fan relay control circuit. This energizes the cooling fan 2 relay coil, closes the relay contacts, and provides a ground path for the left cooling fan. At the same time the cooling fan 2 relay coil is energized closing the relay contacts and provides battery positive voltage from the cool fan 2 fuse on the cooling fan motor supply voltage circuit to the right cooling fan. During high speed fan operation, both engine cooling fans have there own ground path. The result is a parallel circuit with both fans running at high speed.
The BCM and PCM/ECM command Low Speed Fans on under the following conditions:
?€¢
Engine coolant temperature exceeds approximately 106?°C (223?°F).


?€¢
A/C refrigerant pressure exceeds 1 310 kPa (190 psi).


?€¢
After the vehicle is shut off if the engine coolant temperature at key-off is greater than 140?°C (284?°F) and system voltage is more than 12 volts. The fans will stay on for approximately 3 minutes.

The BCM and PCM/ECM command High Speed Fans on under the following conditions:
?€¢
Engine coolant temperature reaches 110?°C (230?°F).


?€¢
A/C refrigerant pressure exceeds 1 655 kPa (240 psi).


?€¢
When certain DTCs set.


The three relays are located in the under hood fuse / relay box ! You need to have it checked for DTC'S -diagnostic trouble codes ! An you need a GM Tech 2 scan tool !
This diagnostic procedure supports the following DTCs:
?€¢
DTC P0480 Cooling Fan 1 Relay Control Circuit


?€¢
DTC P0481 Cooling Fan 2 and 3 or S/P Relay Control Circuit


?€¢
DTC P0691 Cooling Fan 1 Relay Control Circuit Low Voltage


?€¢
DTC P0692 Cooling Fan 1 Relay Control Circuit High Voltage


?€¢
DTC P0693 Cooling Fan 2 and 3 or S/P Relay Control Circuit Low Voltage


?€¢
DTC P0694 Cooling Fan 2 and 3 or S/P Relay Control Circuit High Voltage


  1. Install a scan tool.
  2. Turn ON the ignition, with the engine OFF.
  3. With a scan tool, command the Fans Low Speed ON and OFF.
Do the low speed engine cooling fans turn ON and OFF with each command?
Go to Step 3
Go to Step 4

3

Important:: A 3 second delay occurs before the powertrain control module (PCM)/engine control module (ECM) changes the cooling fan speed.
With a scan tool, command the Fans High Speed ON and OFF.
Do the high speed engine cooling fans turn ON and OFF with each command?

Aug 08, 2015 | Cars & Trucks

1 Answer

My car 2008 Chevy Uplander warning light came on stating A/C shut off for engine protection. My question exactly as 1posted 2011. Gauge not Reading. Fan running continuously. Doesn't seem hot.


What gauge not reading , Temperature ? you posted back in 2011 ? You did feel you should take it to the repair shop ? You need to take this to a ASE certified repair facility ! This is a complex electronically controlled cooling system , Three relay's controlled by the ECM -engine control module turn the fans on in two different speeds ! There could be DTC'S diagnostic trouble codes stored in the ECM, HVAC module , BCM !
Circuit/System Description
The engine control module (ECM) commands the fans ON in high speed or low speed. In low speed, the fans are configured in series. In high speed, the fans are configured in parallel.
In low speed operation, the ECM applies ground to the coil side of the low speed fan relay, which is the Fan 1 Relay. Voltage is applied directly to the left cooling fan through the switch side of the low speed fan relay. The right fan is connected in series to the left fan through the de-energized Series/Parallel relay, which is Fan 2 Relay, so that both fans operate at low speed.
In high speed operation, the ECM applies a ground to the coil side of the low speed fan relay, the Series/Parallel relay, and the high speed fan relay, which is the Fan 3 Relay. Voltage is applied directly to the right cooling fan through the switch side of the high speed fan relay. The left cooling fan obtains voltage through the low speed fan relay and ground through the Series/Parallel relay.
When the ECM is commanding a fan relay ON, the voltage of the control circuit should be low, near 0 volts. When the ECM is commanding a fan relay OFF, the voltage of the control circuit should be high, near battery voltage.
One of the relays could be stuck on ! An for the gauge you have to have it removed an fixed , there is a stepper motor behind the gauge needle an they go bad ! Or replace the instrument cluster !

May 14, 2015 | Cars & Trucks

1 Answer

What causes both cooling fans to not run?


Hi Naomi , there is a lot involved in the control of the cooling fans on your vehicle ! There are three fuse's , three relays an a fan control unit !
1. radiator fan main relay , located in underhood relay box A
2.condenser fan relay , located in underhood relay box A
3.radiator fan relay , located in underhood relay box C
4.Cooling fan fuse # 47 20amp. underhood fuse / relay box
5.condenser fan fuse # 50 20amp in underhood fuse / relay box.
Any one of these could cause them to not work, rather then just replacing parts an wasting money you should take it to the repair shop !

Apr 06, 2015 | 1997 Acura RL

1 Answer

I have a 2002 Dodge Intrepid with a code of odb480


This is a generic powertrain diagnostic trouble code (DTC), which means it covers all makes/models, 1996-newer. However, specific troubleshooting steps will vary depending your vehicle. pulling the code P0480 displayed, if refers to the engine cooling fan circuit. It is a generic code applying to all OBD II (on board diagnostics) vehicles. The PCM (powertrain control module) senses the increase in engine temperature through the CTS (coolant temperature sensor) located near the thermostat. When the temperature reaches about 223-degrees F (value depends on make/model/engine), the PCM will command the cooling fan relay to turn on the fan. It does so by supplying the ground to the relay.
There is a problem within this circuit causing the fan to fail to operate allowing the engine to overheat while sitting still or driving at a slow speed. When the PCM attempts to activate the fan and senses the command and the result do not match, the code is set. Symptoms may include:
  • Check engine light (malfunction indicator lamp) illumination and code P0480 set
  • Engine temperature will rise when the vehicle stops and idles
Potential Causes The causes for this DTC may include:
  • Faulty fan control relay 1
  • Fan control relay harness is open or shorted
  • Circuit electrical connections poor
  • Faulty cooling fan 1
  • Faulty coolant temperature sensor
  • Fan cooling fan harness is open or shorted
  • Cooling fan circuit poor electrical connection. hope this helps you.

Oct 12, 2014 | 2002 Dodge Intrepid

4 Answers

Why won't the fan motor shut off on my 1991 acura legend?


Hey chandralebea,

Try first by replacing the cooling fan engine temp sensor switch, as this may be the cause.



Good Luck

Jul 29, 2012 | 1991 Acura Legend

1 Answer

1989 Cadillac sedan deville fans keep running when I take key out


This vehicle has four cooling fan control relays . without looking at the vehicle ,just off the top of my hear i would say a relay had stuck contacts inside . Do you know what a relay is an how there work ? The relays are energized by the BCM - body control module , do you know anything about automotive electronic's ? Do you know how to test automotive electrical systems ? Here is a web site for free wiring diagrams http://www.bbbind.com/free_tsb.html Enter vehicle info. year , make , model an engine . Under system click on engine ,then under subsystem cooling fans. click the search button then the blue link.You will see the coolant fan relay , med. speed , low speed , an high speed . Can you tell what speed the fans are running at ? find the appropriate relay an pull it out of the relay center .

Jun 21, 2017 | Cars & Trucks

1 Answer

I'm trying to find out how many cooling fan relays are in a 1999 Ford Taurus SE with the 3.0L Vulcan OHV engine. This model year has done away with the CCRM (Constant Control Relay Module), so the relays...


fuse #9 protects the 2 cooling fan relays.

It looks like the hgh speed cooling fan realy is in a thin box mounted sideways between the battery and fender.

It has high speed relay, autolamp relay, autolamp headlamp relay, horn relay, washer motor relay, wiper hi/lo relay, wiper park relay.

Section 03-03: Engine Cooling 1999 Taurus, Sable Workshop Manual
DESCRIPTION AND OPERATION Electrical System NOTE: With A/C ON, the cooling fan motors will run continuously. Cooling fan motors will not cycle ON and OFF with A/C clutch (2884) .

NOTE: An exception to this is when vehicle speed is over 61 km/h (38 mph) and coolant temperature is below 100°C (212°F), and A/C head pressure is below 1.71 MPA (250 psi). The cooling fan motors will then automatically shut off.

The cooling fan motors are mounted within a fan shroud (8146) behind the radiator (8005) .

Engine Cooling Fan Control CCRM Applications The PCM monitors certain parameters (such as engine coolant temperature, vehicle speed, A/C on/off status, A/C pressure, etc) to determine engine cooling fan needs. The PCM controls the fan operation through the Fan Control (FC) output (single speed fan applications) or the Low Fan Control (LFC) and High Fan Control (HFC) outputs as shown in Table 2. Although the fan control (FC), low speed fan control and high speed fan control relays are normally open relays, the FC/LFC circuit is wired through a voltage inverter inside the CCRM. The voltage inverter ensures that the PCM must turn on (ground) the FC/LFC output to turn the fan off. This is done so the cooling fan will operate in the event of an open FC/LFC circuit.

Stand-Alone Fan Control Relay Applications The PCM monitors certain parameters (such as engine coolant temperature, vehicle speed, A/C on/off status, A/C pressure, etc) to determine engine cooling fan needs. The PCM determines engine cooling fan control requirements and controls the fan operation through the Low Fan Control (LFC) and High Fan Control (HFC) outputs (Table 3).

Jun 29, 2009 | 1999 Ford Taurus

Not finding what you are looking for?
Cars & Trucks Logo

Related Topics:

18 people viewed this question

Ask a Question

Usually answered in minutes!

Top Buick Experts

yadayada
yadayada

Level 3 Expert

75817 Answers

Colin Stickland
Colin Stickland

Level 3 Expert

22156 Answers

Jeff Turcotte
Jeff Turcotte

Level 3 Expert

8180 Answers

Are you a Buick Expert? Answer questions, earn points and help others

Answer questions

Manuals & User Guides

Loading...