Open load or short circuit to battery on Normal Mode Solenoid (NMS).
Check wiring and connectors between the EST::ECU (E112) and EST::CVU::NMS (V197). The battery should be disconnected during measurements. 1. Check connnectors: - Disconnect harness connectors on both ECU side, and NMS side. - Visually check connectors for defects connecting E112 and V197. 2. Check solenoid: - Disconnect harness connector on both ECU side, and NMS side. - Measure the resistance on the solenoid component between pins V197::1 and V197::2. - Should be 8 ohm at +20°C If resitance about none or infinite replace solenoid. 3. Check Wiring - Disconnect harness connector on both ECU side, and DLS side. - Check cable harness for defects. - Measure the resistance over the cables between pins E112::A4 and V197::1. It should be 0 ohm. If not cable broken. - Measure the resistance over the cables between pins E112::A6 and V197::2. It should be 0 ohm. If not cable broken. - Measure the resistance over the cables between pins E112::A4 and E112::A6. It should be infinite. If not cables has broken isolation or shorcicuit in cable connectors. - Connect the connector on NMS side. - Measure the resistance over the cables between pins E112::A4 and E112::A6. It should be about same resistance as in step 2. If not indicates shortcircuit connector coupling between NMS and cable. Verify that the issue is solved by performing a Diagnostic SelfTest (requires Parking Brake to be applied) - If the root cause fault has been fixed, this DTC will be set passive.
What you'll see
When NMS is not working piston is no longer controlable and further degradation can appear if necessary.
System reaction
Red Steer tag axle fault warn EST in released or fixed mode
Diagnostic depth
High or low current level detected on circuit in OFF or ON state for NMS.
* Wiring - Connecting cables are broken * Connectors - Connector on NMS defect - Connector on EST defect * NMS - defect solenoid