C1358 – Decreasing pressure solenoid (right rear) (Toyota)

Toyota-specific code — factory diagnostic data

C1358 means your Toyota C-HR’s ABS system sees a problem with the right rear brake pressure “decrease” control. You may notice ABS, VSC, or traction control warnings, and those safety features may reduce operation. According to Toyota factory diagnostic data, this is a Toyota-defined chassis code for the ABS/VSC/TRC system and it targets the decreasing pressure solenoid for the right rear hydraulic circuit. This code does not prove the solenoid has failed. It tells you the module detected an electrical or functional fault in the solenoid circuit or in how that solenoid responded during self-checks or active control.

C1358 Quick Answer

C1358 on Toyota points to the ABS/VSC/TRC right rear “decreasing pressure” solenoid circuit or its commanded operation. Confirm power, ground, wiring integrity, and solenoid response with scan-tool active tests before replacing parts.

What Does C1358 Mean?

Official definition (Toyota): “Decreasing pressure solenoid (right rear).” In plain terms, the ABS/VSC/TRC module flagged the part of the brake actuator that releases (reduces) hydraulic pressure to the right rear brake during ABS, stability, or traction events. In real-world driving, the vehicle still brakes normally most of the time. However, ABS, VSC, and TRC can disable or limit control when the module cannot trust that solenoid.

What the module actually checks: the ABS/VSC/TRC module commands the right rear decrease solenoid on and off and monitors the electrical circuit behavior and system response. Depending on Toyota platform design, the module may watch coil current control, driver feedback, and plausibility during self-tests and dynamic events. Why that matters: the DTC points to a suspected trouble area, not a confirmed bad actuator. You must prove whether the fault comes from wiring, a connector, internal actuator circuitry, low system voltage, or the ABS/VSC/TRC module’s solenoid driver logic.

Theory of Operation

During normal braking, the brake actuator’s solenoids stay in a default state and the driver’s pedal input creates brake pressure. When ABS activates, the ABS/VSC/TRC module rapidly controls inlet and outlet (decrease) solenoids to manage wheel slip. The “decreasing pressure” solenoid provides a controlled pressure release path for that wheel circuit.

C1358 sets when the module commands the right rear pressure-decrease function and the circuit or response does not match expectations. An open circuit prevents coil current flow. A short can pull current too high or collapse the driver output. High resistance, water intrusion, or a poor ground can make the solenoid slow or inconsistent, which also breaks ABS control and triggers this DTC.

Symptoms

Drivers usually notice stability and ABS warnings first, then changes in how the safety systems behave.

• Warning lights ABS, VSC, and/or TRC lamps illuminated
• Messages stability/traction control warning message on the cluster (if equipped)
• ABS operation ABS may disable, or it may stop mid-event
• VSC/TRC operation reduced stability and traction interventions, especially on slick surfaces
• Brake feel normal base braking, but abnormal pulsation or no pulsation during a hard stop on loose gravel
• Stored codes related ABS actuator/solenoid or power supply DTCs stored with C1358
• Intermittent behavior lights that come and go with bumps, moisture, or temperature changes

Common Causes

• Open circuit in the right-rear decreasing pressure solenoid control wiring: A broken wire stops current flow, so the ABS/VSC/TRC cannot drive the solenoid and flags the circuit as faulty.
• Short to ground in the solenoid control circuit: Chafed insulation can ground the control line, which forces abnormal current and disables normal pressure reduction control.
• Short to B+ in the solenoid control circuit: Battery voltage on the control line can hold the driver in an invalid state and the module detects an electrical mismatch.
• High resistance at the actuator/solenoid connector: Corrosion or spread terminals raise resistance, which reduces commanded current and causes an out-of-range electrical response.
• Internal failure of the right-rear decreasing pressure solenoid coil: A coil with an open winding or partial short changes coil resistance and current draw beyond what the module expects.
• Poor ABS actuator assembly power or ground feed: A weak supply or ground creates low driver headroom, so multiple solenoid circuits can fail under load.
• Harness damage near the ABS actuator or along the rear body harness route: Flexing and vibration can rub through insulation, especially at clips and grommets, creating intermittent opens or shorts.
• Water intrusion at connectors or into the actuator area: Moisture promotes corrosion and terminal fretting, which makes the fault appear during braking events or after rain washes.

Diagnosis Steps

Use a scan tool that can access Toyota ABS/VSC/TRC data, active tests, and freeze frame. You also need a DVOM, a test light or fused jumper, and back-probing tools. Plan for voltage-drop testing under load. Service information and connector pinouts matter here because Toyota actuator layouts vary by platform.

1. Confirm DTC C1358 in the ABS/VSC/TRC module and record freeze frame data. Focus on battery voltage, ignition state, vehicle speed, and any brake/ABS command status shown. Freeze frame captures conditions when the DTC set. Use a scan-tool snapshot later to catch intermittents during a drive or stall test.
2. Check for related ABS/VSC/TRC DTCs and address power-supply or actuator codes first. Then perform a quick visual inspection of the circuit path. Look for harness rubs, recent brake work, collision damage, or rodent activity near the ABS actuator and the rear harness routing.
3. Check fuses and power distribution feeding the ABS/VSC/TRC and actuator motor/solenoid circuits. Verify each related fuse carries power with the correct ignition state. Do not start pin testing at the module until you confirm supply integrity.
4. Verify ABS/VSC/TRC power and ground quality with voltage-drop tests under load. Command an ABS function with the scan tool when possible, or load the circuit with a suitable test light per service info. Measure ground drop while the circuit operates. Keep ground drop under 0.1 V. A weak ground can mimic a “bad solenoid” every time.
5. Inspect the ABS actuator assembly connector and terminals. Check for bent pins, water tracks, corrosion, and terminals that feel loose during a light tug test. Correct any terminal fit issues before deeper testing, because Toyota solenoid drivers react strongly to small resistance changes.
6. Clear DTCs and key-cycle the vehicle. If C1358 returns immediately at key-on, treat it as a hard electrical fault. If it returns only after a drive or brake event, suspect an intermittent connection, harness movement, or a solenoid that fails when hot.
7. Use scan tool active tests, if available for your Toyota platform, to command the decreasing pressure solenoid for the right rear. Listen or feel for actuator clicking at the unit. Compare its response to other solenoids. If the scan tool reports “test aborted” or the solenoid shows no response, continue with circuit testing.
8. Perform circuit integrity checks between the ABS actuator/solenoid terminals and the module pins, following Toyota wiring diagrams. Use a DVOM to check for opens and shorts between the control line and ground or B+. Wiggle the harness while you test. Do not rely on continuity alone for a high-resistance problem.
9. Load-test the suspect control circuit. Use a test light or an approved resistor load to simulate current flow, then measure voltage drop across connectors and suspect splice points. A circuit can show good continuity and still fail under load due to corrosion or a cracked conductor.
10. If wiring and connectors pass, evaluate the solenoid coil in the actuator assembly per Toyota procedures. Compare its resistance trend to the other solenoids in the same unit and check for instability with gentle heat or vibration. Replace nothing until you prove the electrical path and coil behavior match the fault.
11. After repairs, clear codes and run a verification drive. Repeat the same braking conditions seen in freeze frame when safe. Use a scan-tool snapshot to capture solenoid command states and battery voltage during the event. Confirm C1358 stays out and ABS/VSC/TRC functions normally.

Professional tip: Treat C1358 as a “suspected circuit area” code, not a confirmed part failure. Many Toyota actuator solenoid faults trace back to voltage-drop on grounds or a single weak terminal tension. If the code sets only on bumps or during wet weather, focus on harness movement and connector intrusion first. Freeze frame tells you when it failed. A manual snapshot helps you force the failure while watching voltage and command changes.

Possible Fixes

• Repair open/shorted wiring in the right-rear decreasing pressure solenoid circuit: Fix chafed sections, broken conductors, or pinched harness areas, then protect the routing and retainers.
• Clean, repair, or replace affected terminals/connectors: Restore terminal tension, remove corrosion, and correct water intrusion so the solenoid current stays stable.
• Restore ABS actuator power and ground integrity: Repair high-resistance grounds, loose fasteners, or power-feed issues confirmed by voltage-drop testing under load.
• Replace the ABS actuator/solenoid assembly only after circuit proof: Replace the unit if coil behavior or internal driver response fails tests and you verified all external wiring and supplies.

Can I Still Drive With C1358?

You can usually drive a Toyota C-HR with C1358, but you should treat it as a brake-system warning, not a minor nuisance. This manufacturer-specific ABS/VSC/TRC code points to the right rear decreasing pressure solenoid circuit or the solenoid’s ability to respond. When the module cannot control pressure correctly, it often disables ABS, traction control, and stability control functions. Your base hydraulic brakes typically still work, but emergency braking performance can change. Avoid hard braking, towing, steep descents, and slick roads until you fix the cause. If the brake warning light stays on, the pedal feel changes, or the vehicle pulls under braking, stop driving and inspect the system immediately.

How Serious Is This Code?

C1358 ranges from inconvenient to safety-significant, depending on what failed. If the ABS/VSC/TRC system only lost the right rear pressure-decrease function, you may only notice warning lights and reduced stability control assistance. However, the same code can also appear when the actuator circuit has high resistance, poor power or ground, or an internal hydraulic control issue. Those conditions can affect how evenly the system modulates brake pressure during a skid or panic stop. On dry roads with gentle driving, you may not notice a change. In rain, snow, or gravel, the loss of ABS/VSC/TRC control increases stopping distance and spin risk. Treat any brake-related code as priority and verify the electrical circuit before replacing parts.

Common Misdiagnoses

Technicians often replace the ABS actuator or solenoid assembly too early because the code mentions a solenoid. That wastes money when the real fault sits in the harness, a loose connector lock, water intrusion, or a terminal fit issue near the actuator. Another common mistake involves ignoring power and ground voltage-drop checks under load. The actuator can fail self-tests when supply voltage sags during pump or solenoid actuation. Some shops also chase wheel speed sensors because ABS lights appear, even though C1358 targets pressure control, not speed input. Avoid guesswork by commanding the solenoid with a scan tool, then checking circuit integrity and connector condition before any hydraulic or module replacement.

Most Likely Fix

The most common confirmed repair directions for C1358 on Toyota platforms start with circuit correction, not actuator replacement. First, repair poor connections at the ABS actuator connector, including corrosion, spread terminals, or damaged seals. Next, repair harness damage where it flexes, rubs, or has prior repair splices. If circuit tests pass and the scan tool cannot command a normal solenoid response, then further diagnosis may support ABS actuator or internal solenoid fault. Verify with functional tests and repeat checks after a road test. Drive long enough for the ABS/VSC/TRC self-check to rerun, since enable criteria vary by model and system.

Repair Costs

Repair cost depends on whether the fault is wiring, a solenoid, a valve body component, or internal transmission diagnosis. Confirm the root cause with scan data before committing to a repair.

Last updated: April 9, 2026