2005 GMC 1500 4wd.
Engine size = 5.3 v8 Vortec.
GM Computer codes = B2425
Work done to repair this problem = driver seat module, driver door module,
driver heat switch, driver whole seat swapped with a known good seat, body
harness that goes to both driver and passenger seat, passenger bottom
cushion and back heater element, passenger heat switch, replaced seat
heater circuit breaker by the brake pedal also reprogrammed driver seat
module, driver door module, pcm , bcm.
GM tech = jk
question = I HAVE HAD A HEADACHE WITH THIS TRUCK ALREADY,,, I
GOT A B2425 CODE WHICH IS LEFT FRONT SEAT HEATER CIRCUIT. I
CAN PUSH THE DRIVER SEAT HEATER AND SOMETIMES IT WILL STAY
ON FOR A LIL BIT AND SOMETIMES I CAN PUSH IT AND IT WILL TURN
OFF RIGHT AWAY,,,BUT THE WEIRD THING IS I THINK THE PASSENGER
SIDE WILL STAY ON ALL THE TIME TILL U HIT THE DRIVER SIDE,,,AND
THE OTHER WAY ALSO WHEN U HAVE THE DRIVER SIDE ON AN GO TO
PUSH THE PASSENGER SOMETIMES IT WILL KICK OFF...IS THERE ANY
SUGGESTIONS U MIGHT HELP ME OUT WITH??
Engine size = 5.3 v8 Vortec.
GM Computer codes = B2425
Work done to repair this problem = driver seat module, driver door module,
driver heat switch, driver whole seat swapped with a known good seat, body
harness that goes to both driver and passenger seat, passenger bottom
cushion and back heater element, passenger heat switch, replaced seat
heater circuit breaker by the brake pedal also reprogrammed driver seat
module, driver door module, pcm , bcm.
GM tech = jk
question = I HAVE HAD A HEADACHE WITH THIS TRUCK ALREADY,,, I
GOT A B2425 CODE WHICH IS LEFT FRONT SEAT HEATER CIRCUIT. I
CAN PUSH THE DRIVER SEAT HEATER AND SOMETIMES IT WILL STAY
ON FOR A LIL BIT AND SOMETIMES I CAN PUSH IT AND IT WILL TURN
OFF RIGHT AWAY,,,BUT THE WEIRD THING IS I THINK THE PASSENGER
SIDE WILL STAY ON ALL THE TIME TILL U HIT THE DRIVER SIDE,,,AND
THE OTHER WAY ALSO WHEN U HAVE THE DRIVER SIDE ON AN GO TO
PUSH THE PASSENGER SOMETIMES IT WILL KICK OFF...IS THERE ANY
SUGGESTIONS U MIGHT HELP ME OUT WITH??
GM Tech JK:
Since you have replaced all these parts already, and i assume the modules programmed with
the latest software, then i think this bulletin may help...
Condition/Concern:
Driver and passenger heated seats inoperative or shut off in 30 seconds. There will be DTCs
B2435, B2440, B3606 and/or B1825 set in the Drivers Seat Module. The adjustable pedal
position sensor, seat recliner position sensor and both heat seat thermistors share the same 5
volt reference internal to the Drivers Seat Module. A fault in any of these components/circuits
can make the heated seats inoperative or shut off in 30 seconds, as well as, the seat recliner
and/or adjustment pedals may move in short increments when operated. A fault in heated
seats, adjustable pedal or seat recliner will affect BOTH heated seats.
Note:: Even if the vehicle is not equipped with adjustable pedals DTC B3606 still may set.
Recommendation/Instructions:
To help isolate the area of concern use the Tech 2 and go to "Sensor Data" in the Drivers Seat
Module. Monitor the following parameters for being out of range:
Recline Position- Normal range .39V-4.58V
Pedal Position (if equipped) - Normal range .39V-4.58V
Psgr. Seat Heat Sensor- Normal range 1V-4V
Drvr. Seat Heat Sensor- Normal range 1V-4V
If a parameter is found to be out of range inspect circuits for any opens, shorts to ground, or
voltage. If none found replace the suspect component.
Since you have replaced all these parts already, and i assume the modules programmed with
the latest software, then i think this bulletin may help...
Condition/Concern:
Driver and passenger heated seats inoperative or shut off in 30 seconds. There will be DTCs
B2435, B2440, B3606 and/or B1825 set in the Drivers Seat Module. The adjustable pedal
position sensor, seat recliner position sensor and both heat seat thermistors share the same 5
volt reference internal to the Drivers Seat Module. A fault in any of these components/circuits
can make the heated seats inoperative or shut off in 30 seconds, as well as, the seat recliner
and/or adjustment pedals may move in short increments when operated. A fault in heated
seats, adjustable pedal or seat recliner will affect BOTH heated seats.
Note:: Even if the vehicle is not equipped with adjustable pedals DTC B3606 still may set.
Recommendation/Instructions:
To help isolate the area of concern use the Tech 2 and go to "Sensor Data" in the Drivers Seat
Module. Monitor the following parameters for being out of range:
Recline Position- Normal range .39V-4.58V
Pedal Position (if equipped) - Normal range .39V-4.58V
Psgr. Seat Heat Sensor- Normal range 1V-4V
Drvr. Seat Heat Sensor- Normal range 1V-4V
If a parameter is found to be out of range inspect circuits for any opens, shorts to ground, or
voltage. If none found replace the suspect component.
Please be aware of the following common areas of concern:
The adjustable pedal position sensor internally shorted pulling the 5 volt reference low.
Disconnect the adjustable pedal position sensor and see if the heated seats start working
correctly, if so replace.
Note Important:: The APP (Accelerator Pedal Position) sensor is NOT the adjustable pedal
position sensor. Make sure the correct sensor, adjustable pedal position sensor, is
disconnected.
The seat recliner position sensor internally shorted pulling the 5 volt reference low. Disconnect
the recliner position sensor and see if heated seats start working correctly, if so replace.
An open in either heated seat thermistor circuits (signal or low reference). The most common is
the passenger thermistor where it passes through seat connector C305 pin "L" or "K" or C399
pins "R" or "G".
A chaff to ground on either heated seat thermistor signal circuits. The most common is circuit
5475 black/red or dark blue shorted to ground in the passenger seat near the buckle.
Note Important:: The heated seat thermistors act differently to "OPENS and SHORTS" than the
adjustable pedal position sensor and seat recliner position sensor. The adjustable pedals and
seat recliner sensors can be disconnected for testing of the heated seats. Where as the
heated seat thermistor circuit must be working correctly before EITHER heated seat will
operate. Disconnecting one thermistor, which may have a concern will not allow the opposite
heated seat to work correctly, BOTH side must be operational before EITHER heated seat will
operate.
Clearing DTCs
If DTCs will not clear when using the Tech 2 after a repair has been made, try operating the
device in which the repair was made. Example, if a repair was made to the passenger heated
seat thermistor circuit, the DTCs may not clear unless the passenger heated seat is operated
The adjustable pedal position sensor internally shorted pulling the 5 volt reference low.
Disconnect the adjustable pedal position sensor and see if the heated seats start working
correctly, if so replace.
Note Important:: The APP (Accelerator Pedal Position) sensor is NOT the adjustable pedal
position sensor. Make sure the correct sensor, adjustable pedal position sensor, is
disconnected.
The seat recliner position sensor internally shorted pulling the 5 volt reference low. Disconnect
the recliner position sensor and see if heated seats start working correctly, if so replace.
An open in either heated seat thermistor circuits (signal or low reference). The most common is
the passenger thermistor where it passes through seat connector C305 pin "L" or "K" or C399
pins "R" or "G".
A chaff to ground on either heated seat thermistor signal circuits. The most common is circuit
5475 black/red or dark blue shorted to ground in the passenger seat near the buckle.
Note Important:: The heated seat thermistors act differently to "OPENS and SHORTS" than the
adjustable pedal position sensor and seat recliner position sensor. The adjustable pedals and
seat recliner sensors can be disconnected for testing of the heated seats. Where as the
heated seat thermistor circuit must be working correctly before EITHER heated seat will
operate. Disconnecting one thermistor, which may have a concern will not allow the opposite
heated seat to work correctly, BOTH side must be operational before EITHER heated seat will
operate.
Clearing DTCs
If DTCs will not clear when using the Tech 2 after a repair has been made, try operating the
device in which the repair was made. Example, if a repair was made to the passenger heated
seat thermistor circuit, the DTCs may not clear unless the passenger heated seat is operated
