brake pressure differential switch - c1247
Thread Starter
Drifting
Joined: Nov 2003
Posts: 1,539
Likes: 3
From: South al
brake pressure differential switch - c1247
Does anyone know where the brake pressure differential switch is located? I had to bleed a brake caliper & the dtc set the c1247.I now have the red brake warning light staying, car icon tcs indicator,service tracion system,service active handling.I am 100 % for sure theres no ground loose. I had to go in last night & pull the drivers side axle ,to replace the boot that the brake line rubbed a hole in after the dealer put the tranny in ,btw it took almost a year for the brake line to rub a hole in the boot .I just need to know if anyone can tell me where the pressure switch pressure circuit is located .Thank you for the replys & happy new year .
Team Owner
Joined: Mar 1999
Posts: 22,025
Likes: 192
From: At the beach in little Rhody
Not sure on the C5, but on my C4 when I bled the brakes there is a warning about pumping the pedal too fast and I had similar issues. Try pumping the pedal a few time to see if it clears. What method did you use to bleed the brakes?
Thread Starter
Drifting
Joined: Nov 2003
Posts: 1,539
Likes: 3
From: South al
i had the rear tire, driver side off the car.The driverside caliper has a nut on the back of it .I had my buddy loosen the nut as i pumped the brake , trying to get the air out of the line & to get some pressure on the pedal ,then we topped off the master cylinder .I have good brakes but i am still getting the 1247.
Tech Contributor
Joined: Oct 1999
Posts: 41,044
Likes: 9,808
From: Charlotte, NC (formerly Endicott, NY)
C1247 varies with year so it is helpful to know what year car you have. In a 2003 it applies to the Brake Fluid Level sensor and in a 1998 it applies to the Brake Fluid Differential Switch I will give you a portion of both diagnostic write ups. The related diagnostic tables do not display correctly in a post.
Here is the 1998 description:
DTC C1247 Brake Pressure Differential Switch Activated
Circuit Description
The EBTCM monitors the Brake Pressure Differential Switch to turn off Traction Control and Active Handling if a pressure loss is detected in the hydraulic brake system.
Conditions for Setting the DTC
DTC C1247 can be set anytime, if the EBTCM detects the Brake Pressure Differential Switch has been grounded due to loss of brake pressure or a short to ground.
Action Taken When the DTC Sets
TCS/Active Handling are disabled.
Indicators that turn on:
RED Brake Warning indicator
Car Icon (TCS indicator)
Messages displayed on the DIC:
Service Traction System
Service Active HNDLG
Conditions for Clearing the DTC
Condition for DTC is no longer present and scan tool clear DTC function is used.
Fifty ignition cycles have passed with no DTCs detected.
Diagnostic Aids
DTC C1247 could be set during a hydraulic brake system bleeding procedure if the ignition switch is in the ON position.
It is very important that a thorough inspection of the wiring and connectors be performed. Failure to carefully and fully inspect wiring and connectors may result in misdiagnosis, causing part replacement with reappearance of the malfunction.
An intermittent malfunction can be caused by poor connections, broken insulation, or a wire that is broken inside the insulation.
If an intermittent malfunction exists refer to Testing for Electrical Intermittents in Wiring Systems.
Here is the 2003 description:
DTC C1247
Circuit Description
The brake fluid level switch monitors the level of brake fluid in the master cylinder. When the IPC sees the brake fluid level switch input grounded, it turns ON the red Brake indicator and sends a serial data message to the EBCM that tells the EBCM that the brake fluid level is low.
Conditions for Running the DTC
The ignition is ON.
Conditions for Setting the DTC
The EBCM receives a serial data message from the IPC indicating that the brake fluid level is low.
Action Taken When the DTC Sets
The EBCM disables the TCS/VSES until the DTC becomes a history DTC.
The red Brake warning indicator turns ON.
The Traction Control and Active Handling indicator turns ON.
The DIC displays the following messages:
Low Brake Fluid
Service Traction System
Service Active Handling
The ABS remains functional.
Conditions for Clearing the DTC
The condition for the DTC is no longer present and the DTC is cleared with a scan tool.
The EBCM automatically clears the history DTC when a current DTC is not detected in 100 consecutive drive cycles.
Diagnostic Aids
Inspect the master cylinder reservoir for the proper brake fluid level.
The Brake Pressure Differential Switch (JL4) is attached to the side of the brake combination valve, left front of master cylinder
Bill
Here is the 1998 description:
DTC C1247 Brake Pressure Differential Switch Activated
Circuit Description
The EBTCM monitors the Brake Pressure Differential Switch to turn off Traction Control and Active Handling if a pressure loss is detected in the hydraulic brake system.
Conditions for Setting the DTC
DTC C1247 can be set anytime, if the EBTCM detects the Brake Pressure Differential Switch has been grounded due to loss of brake pressure or a short to ground.
Action Taken When the DTC Sets
TCS/Active Handling are disabled.
Indicators that turn on:
RED Brake Warning indicator
Car Icon (TCS indicator)
Messages displayed on the DIC:
Service Traction System
Service Active HNDLG
Conditions for Clearing the DTC
Condition for DTC is no longer present and scan tool clear DTC function is used.
Fifty ignition cycles have passed with no DTCs detected.
Diagnostic Aids
DTC C1247 could be set during a hydraulic brake system bleeding procedure if the ignition switch is in the ON position.
It is very important that a thorough inspection of the wiring and connectors be performed. Failure to carefully and fully inspect wiring and connectors may result in misdiagnosis, causing part replacement with reappearance of the malfunction.
An intermittent malfunction can be caused by poor connections, broken insulation, or a wire that is broken inside the insulation.
If an intermittent malfunction exists refer to Testing for Electrical Intermittents in Wiring Systems.
Here is the 2003 description:
DTC C1247
Circuit Description
The brake fluid level switch monitors the level of brake fluid in the master cylinder. When the IPC sees the brake fluid level switch input grounded, it turns ON the red Brake indicator and sends a serial data message to the EBCM that tells the EBCM that the brake fluid level is low.
Conditions for Running the DTC
The ignition is ON.
Conditions for Setting the DTC
The EBCM receives a serial data message from the IPC indicating that the brake fluid level is low.
Action Taken When the DTC Sets
The EBCM disables the TCS/VSES until the DTC becomes a history DTC.
The red Brake warning indicator turns ON.
The Traction Control and Active Handling indicator turns ON.
The DIC displays the following messages:
Low Brake Fluid
Service Traction System
Service Active Handling
The ABS remains functional.
Conditions for Clearing the DTC
The condition for the DTC is no longer present and the DTC is cleared with a scan tool.
The EBCM automatically clears the history DTC when a current DTC is not detected in 100 consecutive drive cycles.
Diagnostic Aids
Inspect the master cylinder reservoir for the proper brake fluid level.
The Brake Pressure Differential Switch (JL4) is attached to the side of the brake combination valve, left front of master cylinder
Bill
Thread Starter
Drifting
Joined: Nov 2003
Posts: 1,539
Likes: 3
From: South al
C1247 varies with year so it is helpful to know what year car you have. In a 2003 it applies to the Brake Fluid Level sensor and in a 1998 it applies to the Brake Fluid Differential Switch I will give you a portion of both diagnostic write ups. The related diagnostic tables do not display correctly in a post.
Here is the 1998 description:
DTC C1247 Brake Pressure Differential Switch Activated
Circuit Description
The EBTCM monitors the Brake Pressure Differential Switch to turn off Traction Control and Active Handling if a pressure loss is detected in the hydraulic brake system.
Conditions for Setting the DTC
DTC C1247 can be set anytime, if the EBTCM detects the Brake Pressure Differential Switch has been grounded due to loss of brake pressure or a short to ground.
Action Taken When the DTC Sets
TCS/Active Handling are disabled.
Indicators that turn on:
RED Brake Warning indicator
Car Icon (TCS indicator)
Messages displayed on the DIC:
Service Traction System
Service Active HNDLG
Conditions for Clearing the DTC
Condition for DTC is no longer present and scan tool clear DTC function is used.
Fifty ignition cycles have passed with no DTCs detected.
Diagnostic Aids
DTC C1247 could be set during a hydraulic brake system bleeding procedure if the ignition switch is in the ON position.
It is very important that a thorough inspection of the wiring and connectors be performed. Failure to carefully and fully inspect wiring and connectors may result in misdiagnosis, causing part replacement with reappearance of the malfunction.
An intermittent malfunction can be caused by poor connections, broken insulation, or a wire that is broken inside the insulation.
If an intermittent malfunction exists refer to Testing for Electrical Intermittents in Wiring Systems.
Here is the 2003 description:
DTC C1247
Circuit Description
The brake fluid level switch monitors the level of brake fluid in the master cylinder. When the IPC sees the brake fluid level switch input grounded, it turns ON the red Brake indicator and sends a serial data message to the EBCM that tells the EBCM that the brake fluid level is low.
Conditions for Running the DTC
The ignition is ON.
Conditions for Setting the DTC
The EBCM receives a serial data message from the IPC indicating that the brake fluid level is low.
Action Taken When the DTC Sets
The EBCM disables the TCS/VSES until the DTC becomes a history DTC.
The red Brake warning indicator turns ON.
The Traction Control and Active Handling indicator turns ON.
The DIC displays the following messages:
Low Brake Fluid
Service Traction System
Service Active Handling
The ABS remains functional.
Conditions for Clearing the DTC
The condition for the DTC is no longer present and the DTC is cleared with a scan tool.
The EBCM automatically clears the history DTC when a current DTC is not detected in 100 consecutive drive cycles.
Diagnostic Aids
Inspect the master cylinder reservoir for the proper brake fluid level.
The Brake Pressure Differential Switch (JL4) is attached to the side of the brake combination valve, left front of master cylinder
Bill
Here is the 1998 description:
DTC C1247 Brake Pressure Differential Switch Activated
Circuit Description
The EBTCM monitors the Brake Pressure Differential Switch to turn off Traction Control and Active Handling if a pressure loss is detected in the hydraulic brake system.
Conditions for Setting the DTC
DTC C1247 can be set anytime, if the EBTCM detects the Brake Pressure Differential Switch has been grounded due to loss of brake pressure or a short to ground.
Action Taken When the DTC Sets
TCS/Active Handling are disabled.
Indicators that turn on:
RED Brake Warning indicator
Car Icon (TCS indicator)
Messages displayed on the DIC:
Service Traction System
Service Active HNDLG
Conditions for Clearing the DTC
Condition for DTC is no longer present and scan tool clear DTC function is used.
Fifty ignition cycles have passed with no DTCs detected.
Diagnostic Aids
DTC C1247 could be set during a hydraulic brake system bleeding procedure if the ignition switch is in the ON position.
It is very important that a thorough inspection of the wiring and connectors be performed. Failure to carefully and fully inspect wiring and connectors may result in misdiagnosis, causing part replacement with reappearance of the malfunction.
An intermittent malfunction can be caused by poor connections, broken insulation, or a wire that is broken inside the insulation.
If an intermittent malfunction exists refer to Testing for Electrical Intermittents in Wiring Systems.
Here is the 2003 description:
DTC C1247
Circuit Description
The brake fluid level switch monitors the level of brake fluid in the master cylinder. When the IPC sees the brake fluid level switch input grounded, it turns ON the red Brake indicator and sends a serial data message to the EBCM that tells the EBCM that the brake fluid level is low.
Conditions for Running the DTC
The ignition is ON.
Conditions for Setting the DTC
The EBCM receives a serial data message from the IPC indicating that the brake fluid level is low.
Action Taken When the DTC Sets
The EBCM disables the TCS/VSES until the DTC becomes a history DTC.
The red Brake warning indicator turns ON.
The Traction Control and Active Handling indicator turns ON.
The DIC displays the following messages:
Low Brake Fluid
Service Traction System
Service Active Handling
The ABS remains functional.
Conditions for Clearing the DTC
The condition for the DTC is no longer present and the DTC is cleared with a scan tool.
The EBCM automatically clears the history DTC when a current DTC is not detected in 100 consecutive drive cycles.
Diagnostic Aids
Inspect the master cylinder reservoir for the proper brake fluid level.
The Brake Pressure Differential Switch (JL4) is attached to the side of the brake combination valve, left front of master cylinder
Bill
Tech Contributor
Joined: Oct 1999
Posts: 41,044
Likes: 9,808
From: Charlotte, NC (formerly Endicott, NY)
I haven't checked all of the manuals on the CD but I bet they are the previous version 97-98 through 00 and then the new version from 01 through 04. 01 is where they changed the brake system to improve active handling and to add dynamic rear braking.
Bill
Bill
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