0xD90E04 Trailer Control Modulator pressure sensor-Voltage Below Normal, Or Shorted To Low Source
Action: Check the cables and connectors between central ECU and TCM. Disconnect connector on TCM side. Measure voltage between sensor signal and sensor signal ground. Voltage should be lower then 0.2V. If voltage is higher then there is a problem in the wiring harness. If voltage is lower then connect TCM and set the ECU to After market mode via diagnosis and measure again, if higher then 4.5V then replace TCM. If voltage is not higher then 4.5V, then measure on ECU side. If voltage there is lower then 4.5 V and error is still active then replace ECU.
What you'll see
Symptom:
System reaction
SystemReaction: ESP control restricted. HSA off. Yellow EBS Warning Lamp.
Diagnostic depth
Detection: Measured sensor signal voltage is higher then 4.5V
Cause: Damage in the wiring (low resistance towards other wires) and/or connectors, TCM or central ECU