2007 Saturn relay C0136
Called to a shop to diagnose a C0136 on a saturn relay (same as an uplander) service info is vague at best. Essentially replace module, if module doesn't fix replace hydraulic unit. It even states that there is no way to diagnose. Shop went with a used hydraulic unit. Same code. A different used hydraulic unit. WTH? So today I go to shop with a strategy. Let's figure out where on the module or hydraulic unit it gets the pressure value. But 1st let's do a visual comparison of the modules and hydraulic units. See attached photos. One with 2 insternal switches is the original. 2 with only 1 are the used replacements. So there is a way to diagnose. But the visual is all I needed. Hope this helps someone.
DTC C0136 - Base Brake System Pressure Circuit/Sensor
The brake pressure sensor is mounted to the brake pressure modulator valve (BPMV) under the EBCM and cannot be diagnosed. If equipped, the brake pressure sensor 5-volt reference circuit and low reference circuit is shared with other components in the vehicle stability system. DTCs can set for other components that share circuits with the brake pressure sensor. * DTC C0870 is set if the 5-volt reference voltage is out of range.
what the code description? i could not find that code. I've had several abs modules go bad the have broken solders on the circuit board.