B1622

Code

Other B — Body

Wiper Rear Low Limit Input Circuit Short To Ground

Brand: Other

Type: B — Body

Views: UK: 25 EN: 36 RU: 21

AI status

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Page language: EN

Causes

Damaged or chafed wiring shorting the low-limit circuit to chassis ground
Corroded or pushed-back connector pins at the rear wiper motor or body control module (BCM)
Failed low-limit switch or position sensor inside the rear wiper motor assembly
Water intrusion or corrosion in the rear hatch harness or connector
Aftermarket installations or accident damage altering wiring routing
Faulty BCM or poor ground/return at module (less common)

Symptoms

Rear wiper will not park correctly or stops mid-sweep
Rear wiper may run continuously or refuse to stop in park position
Rear wiper inoperative (no movement) with stored B1622 code
Intermittent wiper operation or erratic parking
Possible diagnostic trouble lamp or message indicating wiper system fault

What to check

Use a scan tool to read DTC B1622 and any related codes; view live data for rear wiper limit/park input
Visually inspect rear hatch wiring, connector and wiper motor for damage, corrosion or water intrusion
Check related fuses and relays for the rear wiper circuit
With ignition ON, backprobe the low-limit input pin at the wiper motor connector and at the BCM connector (if accessible) and note voltage
Perform continuity/resistance checks between the low-limit circuit and chassis ground with connectors disconnected
Wiggle harness around the hatch hinge while observing live data or test lamp to reproduce intermittent short

Signal parameters

Expected voltage at low-limit/park input with circuit open (no short): approx. battery voltage (~11–14 V) via internal pull-up from control module (varies by vehicle)
Voltage when low-limit switch is activated/grounded by motor: near 0 V (ground)
If circuit is shorted to chassis ground, measured voltage at the module or harness will be ~0 V with ignition ON (when it should be pulled high)
Typical resistance of closed switch to ground: near 0–5 ohms; open switch: very high/OL. Wiring to ground will measure near 0 ohms if shorted

Diagnostic algorithm

Confirm code: clear code and attempt a rear wiper cycle while monitoring for code reappearance and live data for the low-limit input
Visual inspection: examine rear hatch harness, grommets and connector at the wiper motor for damage, pin corrosion or water intrusion
Backprobe tests: with ignition ON (engine off), backprobe the low-limit input at the wiper motor connector and at the BCM (if accessible). Record voltage. Expected: pulled high (~12 V) when not grounded; ~0 V when switch closes. If always ~0 V, there is a short to ground.
Isolate harness: disconnect the rear wiper motor connector. Measure voltage at the harness pin coming from the vehicle (not the motor). If voltage is now normal (pulled high), the short is inside the motor/its connector. If still low/0 V, the short is upstream in the harness or module.
Continuity to ground: with battery negative disconnected, check continuity between the low-limit signal wire and chassis ground. A near-zero reading indicates a short. If open/infinite, the wiring is OK.
Sectional isolation: if the harness is long, disconnect sections (inner body harness vs. hatch harness) and retest to localize the short. Pay particular attention to hinge area where wires flex.
Connector/pin inspection: examine pins for pushed-back terminals, corrosion, or contact between signal and ground terminals. Repair or replace damaged connector/terminals.
Motor/switch test: if harness is OK and the short follows the motor connector, remove the motor and bench test the low-limit switch/resistor inside per manufacturer procedure. Replace motor assembly if internal switch is faulty.
Module check: if wiring and motor check good, verify BCM outputs and grounds. Confirm no module damage and reflash or replace module only after wiring and motor faults are ruled out.
Confirm repair: after repair, clear codes, perform functional wiper test cycles and verify the low-limit input behaves correctly and code does not return

Likely causes

Chafed/crushed harness at rear hatch hinge causing short to ground
Corroded connector at rear wiper motor drawing the signal to ground
Failed low-limit switch inside rear wiper motor assembly
Water damage in connector or harness

Fault status

⚠️ Status

Wiper Rear Low Limit Input Circuit Short To Ground (low-limit/park circuit pulled to chassis ground)

🟡 Repair difficulty: Medium

⏱️ Diagnostic time: 0.5-2.0 hours

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