Code

[donandmax]

Code tcs pwn link..(PO) Whats this ? Anybody know ?? And how serious is this code....

[Roadcapt]

Must be a rare one, car running ok?

[Cadillac Jim]

I can't find "pwn link (PO)" in my list of OBD codes. What is the code number?

[donandmax]

I can't find "pwn link (PO)" in my list of OBD codes. What is the code number?

P 1571

[Cadillac Jim]

P1571 Traction Control Torque Request Circuit

This is one of the wires between the EBTCM and the PCM that is used by the TCS, ABS and Stabilitrak, which reside in the EBTCM. The signal is a pulse-width modulation (PWM) type, where the value is determined by the percentage of time the voltage is high (probably +5 Volts) versus the percentage of time that it is near ground.

My information is from the 1997 model year FSM pages 8A-44-0 and 8A-44-1. The torque command PWM circuit is a very simple circuit, consisting of two wires between the EBTCM and the PCM. They are ORN/BLK (requested torque PWM) and TAN/BLK (delivered torque PWM). They connect to terminals 27 and 46 of the EBTCM C2 connector and to terminals 6 and 25 of the PCM C2 connector. Either one (or both) connectors has a poor connection, or there is a problem with a fuse.

Fuses to check are the 20 Amp STOP fuse in the engine compartment fuse/relay center (this one is just for the braking signal), the 10 Amp ABS fuse in the engine compartment fuse/relay center, and the 50 Amp BRAKES MaxiFuse in the RH MaxiFuse block. Any one of these fuses will cause multiple codes, so the problem is likely in one of the connectors.

I would venture it's the EBTCM connector, mostly because it's the hardest one to get to. Unless the EBTCM connector is disconnected before the engine cradle is dropped for any reason, the engine hangs on this connector and the connector clamp and the connector itself can be damaged - i.e. one or more wires can be pulled out of the connector. I had a mechanic do this to mine and he just jammed the wire back into the connector; it caused problems for a year before another mechanic found it with an ohmmeter.

Another thing to check is the grounds on the EBTCM. There are two. The electronics ground is on the connector, a large BLK wire on terminal B of connector C1 on the EBTCM, and it goes to ground G110. The other is a wire held by a screw on the back of the ABS pump motor, and is a large BLK wire that goes to ground G107. Both grounds *must* be good and essentially zero resistance as measured by an ohmmeter; if not, clean the connections to ground.

Both grounds G107 and G110 are on the left front corner of the engine below the thermostat housing, according to page 8A-44-5. On my car they are now chassis grounds, which seems to work OK for me - either someone changed them or the FSM could be incorrect on this point and they came that way. A GM tech had no problem finding and fixing mine.

[donandmax]

P1571 Traction Control Torque Request Circuit

This is one of the wires between the EBTCM and the PCM that is used by the TCS, ABS and Stabilitrak, which reside in the EBTCM. The signal is a pulse-width modulation (PWM) type, where the value is determined by the percentage of time the voltage is high (probably +5 Volts) versus the percentage of time that it is near ground.

My information is from the 1997 model year FSM pages 8A-44-0 and 8A-44-1. The torque command PWM circuit is a very simple circuit, consisting of two wires between the EBTCM and the PCM. They are ORN/BLK (requested torque PWM) and TAN/BLK (delivered torque PWM). They connect to terminals 27 and 46 of the EBTCM C2 connector and to terminals 6 and 25 of the PCM C2 connector. Either one (or both) connectors has a poor connection, or there is a problem with a fuse.

Fuses to check are the 20 Amp STOP fuse in the engine compartment fuse/relay center (this one is just for the braking signal), the 10 Amp ABS fuse in the engine compartment fuse/relay center, and the 50 Amp BRAKES MaxiFuse in the RH MaxiFuse block. Any one of these fuses will cause multiple codes, so the problem is likely in one of the connectors.

I would venture it's the EBTCM connector, mostly because it's the hardest one to get to. Unless the EBTCM connector is disconnected before the engine cradle is dropped for any reason, the engine hangs on this connector and the connector clamp and the connector itself can be damaged - i.e. one or more wires can be pulled out of the connector. I had a mechanic do this to mine and he just jammed the wire back into the connector; it caused problems for a year before another mechanic found it with an ohmmeter.

Another thing to check is the grounds on the EBTCM. There are two. The electronics ground is on the connector, a large BLK wire on terminal B of connector C1 on the EBTCM, and it goes to ground G110. The other is a wire held by a screw on the back of the ABS pump motor, and is a large BLK wire that goes to ground G107. Both grounds *must* be good and essentially zero resistance as measured by an ohmmeter; if not, clean the connections to ground.

Both grounds G107 and G110 are on the left front corner of the engine below the thermostat housing, according to page 8A-44-5. On my car they are now chassis grounds, which seems to work OK for me - either someone changed them or the FSM could be incorrect on this point and they came that way. A GM tech had no problem finding and fixing mine.

Oh WOW Jim,sounds like this will be a real booger to find.why oh why did they make these cars so darn complicated ?? I would have preferred just the minimum (engine, four wheels, brakes etc.) I dont know if I can even find this stuff. But thanks for the info anyhow..

Regards

Don

[Cadillac Jim]

Actually this isn't any more complicated than any other electrical problem on any car. Check one wire, ORN/BLK by pulling on it on both the EBTCM and PCM connectors. If it comes loose, fix it. Check two grounds on both ends of the two BLK wires. Be careful of wires and connectors that connect directly to modules because they are static sensitive. You're done.