00301 – ABS return flow pump (V39) 35-00 - - Pump works, controller is rebuilt, BRAKE light comes on at 10 mph
I’m stumped. The ABS rebuilder has graciously tested the ABS controller twice, and it works for them. Since rebuilding, it now exhibits a new error: 00301 – ABS return flow pump (V39) 35-00 - - . However, the ABS pump appears to rotate when 12VDC is applied directly to the contacts.
So the rebuilder says the ABS controller is fine – but it does not appear to turn the ABS pump, which runs great on 12VDC.
The 2005 8H Audi S4 cabriolet first exhibited an Intermittent error code: 01435 - Brake Pressure Sensor 1 (G201) 57–00 Electric Circuit Failure, also 48-00 Supply Voltage. The ABS controller (only) for 0 265 225 239, Esp 012 09A, 487289, Bosch part # 0 265 950 106, Bosch 5.7, was removed and sent to BBA for remanufacture.
Before sending the ABS controller in, the driver complained of a soft brake pedal, so the car was sent to the dealer for a brake fluid replacement and mechanical component check, with the understanding that the ABS controller was not operational (but was communicating). The car appeared to drive and brake acceptably, with the brake sensor error code 01435 - Brake Pressure Sensor 1 (G201) 57–00 Electric Circuit Failure still showing. The sensor tested normally when disconnected from the harness.
While waiting on the controller, the tires were replaced and the wheels were refinished.
Upon reinstallation of the remanufactured ABS controller, a new error code appeared as stated by VAG-COM: 00301 – ABS return flow pump (V39) 35-00 - - . The controller was sent back to BBA for warranty repair.
After reinstalling the ABS controller, the car still exhibits a 00301 error code, as before, starting when the car reaches 10 mph. This code coincides with a flashing red BRAKE light accompanied by the solid yellow electronic stability program (ESP) light and solid yellow ABS light. The flashing BRAKE light disappears after turning the car off and restarting, but the ABS light, the electronic stability program light and the error code (within VAG-COM) remain. Brake pressures, switches and wheel speed sensors appear to have normal values, as do all other measuring blocks through 6. The pump makes noise when 12VDC is applied directly to the spring electrical contact tangs, both polarities (with the ABS controller removed).
• The Ross-tech VAG-com ABS function test cannot make the return flow pump run with the controller connected in the car. The function test does trigger the 00301 error code.
• The pump runs consistently when tested directly from the spring contacts with 12VDC.
• Resistance on pump contacts (isolated) is 0.4 ohms.
• The contacts between the ABS valve block and the controller have been checked, cleaned, and make good electrical and mechanical contact.
• The wiring harness and connector has tested successfully for the following: positive voltage picked up at pins 2, 6, and 23, and good grounds at pin 1 and pin 5.
• The wiring harness contacts and fuses are verified through the Bentley factory manual for the 2005 Audi S4 cabriolet.
• The previous error code which the ABS controller exhibited as sent to BBA rebuilder, 01435 – Brake Pressure Sensor 1, has not returned. The sensor returns normal values as I step on the brake.
• The car had never before exhibited an error code related to 00301, and that is the only related code present now.
• No germane warning lights or error codes are present after clearing codes. They occur after driving. Only 00301 remains.
• The BRAKE, ABS and ESP lights activate consistently at around 10 mph.
• Brake pressures, switches and wheel speed sensors appear to have normal values.
• The car does exhibit typical radio codes and comfort / convenience code error messages, as it has for several years. These do not appear to be a part of the problem.
• Fuses checked (for resistance, not just visually): 50 amp fuse S123 (50A) in driver’s side dash panel, in relay carrier (4-pin) with threaded connection, S7 (10A) S13 (10A), S14 (10A) and S242 (25A), aka fuse 42 in block.
• Have not yet checked fuse S102 (15A) - the ECM fuse, within the plenum chamber. It is not likely to be the cause, as there is no ECM code.
• The ABS controller has been recoded, no change was seen.
• Brake fluid is full.
Thoughts? I hate to send the valve block in if there is a simple answer. Is there some secret code that turns the pump off, once it has malfunctioned? And what physical happening triggers 00301 – ABS return flow pump (V39) 35-00 ? Pump current or resistance outside parameters, or lack of a successful test at 10 mph?
i have a full diagnostic scan, but I have not yet posted it...unremarkable except for the ABS code.
RichS
I’m stumped. The ABS rebuilder has graciously tested the ABS controller twice, and it works for them. Since rebuilding, it now exhibits a new error: 00301 – ABS return flow pump (V39) 35-00 - - . However, the ABS pump appears to rotate when 12VDC is applied directly to the contacts.
So the rebuilder says the ABS controller is fine – but it does not appear to turn the ABS pump, which runs great on 12VDC.
The 2005 8H Audi S4 cabriolet first exhibited an Intermittent error code: 01435 - Brake Pressure Sensor 1 (G201) 57–00 Electric Circuit Failure, also 48-00 Supply Voltage. The ABS controller (only) for 0 265 225 239, Esp 012 09A, 487289, Bosch part # 0 265 950 106, Bosch 5.7, was removed and sent to BBA for remanufacture.
Before sending the ABS controller in, the driver complained of a soft brake pedal, so the car was sent to the dealer for a brake fluid replacement and mechanical component check, with the understanding that the ABS controller was not operational (but was communicating). The car appeared to drive and brake acceptably, with the brake sensor error code 01435 - Brake Pressure Sensor 1 (G201) 57–00 Electric Circuit Failure still showing. The sensor tested normally when disconnected from the harness.
While waiting on the controller, the tires were replaced and the wheels were refinished.
Upon reinstallation of the remanufactured ABS controller, a new error code appeared as stated by VAG-COM: 00301 – ABS return flow pump (V39) 35-00 - - . The controller was sent back to BBA for warranty repair.
After reinstalling the ABS controller, the car still exhibits a 00301 error code, as before, starting when the car reaches 10 mph. This code coincides with a flashing red BRAKE light accompanied by the solid yellow electronic stability program (ESP) light and solid yellow ABS light. The flashing BRAKE light disappears after turning the car off and restarting, but the ABS light, the electronic stability program light and the error code (within VAG-COM) remain. Brake pressures, switches and wheel speed sensors appear to have normal values, as do all other measuring blocks through 6. The pump makes noise when 12VDC is applied directly to the spring electrical contact tangs, both polarities (with the ABS controller removed).
• The Ross-tech VAG-com ABS function test cannot make the return flow pump run with the controller connected in the car. The function test does trigger the 00301 error code.
• The pump runs consistently when tested directly from the spring contacts with 12VDC.
• Resistance on pump contacts (isolated) is 0.4 ohms.
• The contacts between the ABS valve block and the controller have been checked, cleaned, and make good electrical and mechanical contact.
• The wiring harness and connector has tested successfully for the following: positive voltage picked up at pins 2, 6, and 23, and good grounds at pin 1 and pin 5.
• The wiring harness contacts and fuses are verified through the Bentley factory manual for the 2005 Audi S4 cabriolet.
• The previous error code which the ABS controller exhibited as sent to BBA rebuilder, 01435 – Brake Pressure Sensor 1, has not returned. The sensor returns normal values as I step on the brake.
• The car had never before exhibited an error code related to 00301, and that is the only related code present now.
• No germane warning lights or error codes are present after clearing codes. They occur after driving. Only 00301 remains.
• The BRAKE, ABS and ESP lights activate consistently at around 10 mph.
• Brake pressures, switches and wheel speed sensors appear to have normal values.
• The car does exhibit typical radio codes and comfort / convenience code error messages, as it has for several years. These do not appear to be a part of the problem.
• Fuses checked (for resistance, not just visually): 50 amp fuse S123 (50A) in driver’s side dash panel, in relay carrier (4-pin) with threaded connection, S7 (10A) S13 (10A), S14 (10A) and S242 (25A), aka fuse 42 in block.
• Have not yet checked fuse S102 (15A) - the ECM fuse, within the plenum chamber. It is not likely to be the cause, as there is no ECM code.
• The ABS controller has been recoded, no change was seen.
• Brake fluid is full.
Thoughts? I hate to send the valve block in if there is a simple answer. Is there some secret code that turns the pump off, once it has malfunctioned? And what physical happening triggers 00301 – ABS return flow pump (V39) 35-00 ? Pump current or resistance outside parameters, or lack of a successful test at 10 mph?
i have a full diagnostic scan, but I have not yet posted it...unremarkable except for the ABS code.
RichS
Last edited:
