By iCarsoft Official Store Technical Team, Automotive Diagnostics Editors · Updated October 16, 2026 · Technical sources checked
Quick Answer
The U0159 code means lost communication with parking assist control module a. It does not prove that a bumper sensor or the parking controller is necessarily defective. Save the scan, identify the exact architecture, and test the physical and electrical paths before selecting a repair.
What Does the U0159 Code Mean?
The U0159 code means Lost Communication With Parking Assist Control Module A. The full fault record determines the test branch.
The generic name identifies a parking-assist controller, not an individual bumper sensor. A blocked ultrasonic sensor, a camera image and missing controller messages are different diagnostic branches. Confirm which installed parking system and controller A the manufacturer maps to the complete fault.
The reporting controller and the missing controller are different roles. U0159 stored in one ECU does not prove that ECU is defective. Compare which modules expected the parking-assist module A messages and which nodes remain reachable.
The current Snap-on and Autel references agree on this missing-communication label. They do not provide this vehicle’s architecture or replacement criteria. Obtain current VIN-specific information, including the complete module text and any failure suffix.
Record whether the entire supported parking function is unavailable or whether only one sensor or view is affected. Read the parking controller directly when supported. An unavailable aid does not justify replacing every sensor, and an accessible camera does not establish that the parking-assist network node is healthy.
Save the full module wording and suffix before clearing; they can change the test path.
Separate U0159 from adjacent fault families
| Code | General description | Key distinction |
|---|---|---|
| U0159 | Lost Communication With Parking Assist Control Module A | Identify the named node and reporting controller. |
| U0155 | Lost communication with instrument cluster | A separate display/controller family, not the same node. |
| U0073 | Control module communication bus A off | A bus-level record needs topology identification. |
| P0562 | System voltage low | A supply event can be relevant but does not prove this communication cause. |
Record the complete U0159 description. The suffix, reporting module and companion faults can change the diagnostic path. Use the manufacturer's full wording and test procedure for the exact vehicle.
U0159 Symptoms and Likely Causes
Record U0159 symptoms and fault status; symptoms alone cannot identify a failed part.
Check whether companion faults share a proven cause.
Record whether the entire supported parking function is unavailable or whether only one sensor or view is affected. Read the parking controller directly when supported. An unavailable aid does not justify replacing every sensor, and an accessible camera does not establish that the parking-assist network node is healthy.
Record the controller that stored the fault and any visible warning. A secondary warning is not a parts verdict.
Save the timing and event state before clearing. Present communication does not disprove an earlier interruption.
Review documented bumper, trailer-accessory or parking-system work. A timing association warrants inspection but is not proof of cause.
Practical cause-checking order
- Identity and equipment: The generic name identifies a parking-assist controller, not an individual bumper sensor. A blocked ultrasonic sensor, a camera image and missing controller messages are different diagnostic branches. Confirm which installed parking system and controller A the manufacturer maps to the complete fault. Incorrect option identification or a translated label can send testing to the wrong assembly.
- Shared prerequisite: A demonstrated loss of required feed or ground can prevent an otherwise functional node from communicating. Test in the required operating state rather than assuming a visible fuse is sufficient.
- Connection path: Inspect the branch disturbed during bumper, trailer-accessory or parking-system work. Connector seating, terminal condition and harness protection are evidence to test, not an excuse to replace the named controller.
- Network branch: Compare the reachable module pattern with the OEM network drawing. Shared losses may point toward a common branch or gateway, while one missing node requires its own prerequisites to be checked.
- Controller decision: Consider internal controller or software issues only through the exact OEM diagnostic outcome. An inaccessible ECU is not automatically internally failed; document coverage limitations too.
Did U0159 appear after recent bumper, trailer-accessory or parking-system work? Recheck the documented connections, parts and setup steps affected by that work. Record battery and software history; a post-repair code does not prove the new part is defective.
How Serious Is U0159, and Can You Drive?
The code does not establish a safe driving distance. Follow the owner manual and actual warning state. Avoid relying on an unavailable assistance or warning function. Stop safely and arrange qualified inspection or towing when braking, steering, essential warnings or other safety functions are abnormal.
Record warning messages, operating conditions and service history. Do not induce wheel slip, emergency braking or a handling event on public roads. A red stop warning or abnormal control overrides any verification plan.
Stop and arrange a tow if braking, steering, essential warnings or other safety functions are abnormal.
Do not disconnect network nodes on a moving vehicle, bridge communication wires or use a generic resistance measurement as a universal diagnosis. Safe isolation, sleep/wake state and approved measurement points depend on the installed architecture.
How to Diagnose U0159 in the Right Order
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Preserve the complete event
Save every accessible controller before clearing. Record U0159, its full description, reporting ECU, active/history status, available freeze frame, warning state and the real service timeline. A photo of the five-character label is insufficient because it omits the context needed to select the branch.
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Identify the named function
The generic name identifies a parking-assist controller, not an individual bumper sensor. A blocked ultrasonic sensor, a camera image and missing controller messages are different diagnostic branches. Confirm which installed parking system and controller A the manufacturer maps to the complete fault. Confirm VIN, option equipment and module identification. A generic tool label can help locate the reference family but cannot establish the connector, protocol, wiring colors, wake signal or repair criteria. Read current service information for the actual system.
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Map the communication pattern
Record whether the entire supported parking function is unavailable or whether only one sensor or view is affected. Read the parking controller directly when supported. An unavailable aid does not justify replacing every sensor, and an accessible camera does not establish that the parking-assist network node is healthy. Build a simple list of responding and nonresponding modules in the original event state. Distinguish unsupported scan-tool access from a confirmed vehicle communication failure. Do not infer that every nearby controller shares the same network.
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Check the permitted external path
Follow the prescribed electrical safety procedure and inspect accessible relevant connectors and routing. On the restricted GM applications described by PIP5094, terminal fit is a preliminary concern; that example does not establish a universal fault location or authorize probing this vehicle without its procedure.
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Prove the failed branch
Use the approved test points and the OEM’s required power, wake and bus conditions. Compare measured supply or communication evidence with the scan pattern. Do not import a generic pin, resistance, voltage or termination value. If the evidence does not separate the alternatives, record the limitation and authorize further diagnosis.
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Verify the original function
After a proven repair, confirm required setup and communication in the original operating state. Record whether the entire supported parking function is unavailable or whether only one sensor or view is affected. Read the parking controller directly when supported. An unavailable aid does not justify replacing every sensor, and an accessible camera does not establish that the parking-assist network node is healthy. Save the final scan and functional result. Clearing an event is a memory operation, while restored communication and restored function require their own evidence.
Specifications are vehicle-specific. Use the exact VIN specifications, approved test points and required operating state. No generic value or drive cycle can replace the applicable procedure. Manufacturer examples here do not establish specifications for other applications.
U0159 Repairs and Cost Planning
A U0159 repair must address the demonstrated failure. Do not replace an assembly from the code alone.
Recheck installation and required setup after repair. Repair only the demonstrated branch and document required setup; a symptom alone is not a replacement criterion.
Ask the shop to name the failed branch and the measurement supporting each proposed repair.
Authorize diagnosis before parts while the cause remains uncertain.
| Possible path | Quote basis |
|---|---|
| Proven power, ground or terminal repair | VIN-specific quote |
| Demonstrated communication-branch repair | VIN-specific quote |
| Applicable configuration or software operation | VIN-specific quote |
| Confirmed controller repair plus required setup | VIN-specific quote |
These are alternative repair paths, not prices to add together. Request a VIN-specific quote separating diagnosis, parts, labor, fluids, taxes, required setup and verification. Ask which failed test supports the proposed repair and whether warranty coverage applies.
Using iCarsoft CR Ultra P for U0159
On a supported vehicle, iCarsoft CR Ultra P can save accessible faults, available freeze frame, live data and diagnostic reports. Preserve the U0159 evidence before clearing.
Compare the saved and final module records. Scan data supports diagnosis but does not replace the OEM reference, physical measurement or safety-system functional check.
Preserve the parking-assist module A messages evidence
iCarsoft CR Ultra P
Review supported codes and relevant live data together. Confirm the exact VIN, controller access, PIDs and any requested active test with iCarsoft before purchase; generic product capabilities do not guarantee a U0159-specific function.
Check current CR Ultra P price and availabilityCheck CR Ultra P compatibility by VINThe official product page describes supported full-system diagnostics, available live data, freeze frame and diagnostic reports; exact ECU access and functions depend on the VIN and software. Confirm the requested function by VIN before purchase. Follow OEM prerequisites and stop for abnormal operation.
Know the measurement boundary. Scan data describes ECU-provided information; it does not directly prove the physical condition of the parking-assist module A messages. Where required, use the OEM wiring diagram, approved terminal tools and any prescribed network test equipment and compare reported values with the relevant measured evidence.
Verify the U0159 Repair
After repair, verify installation, clearance and required setup. Save the final findings and clear only erasable records as instructed. Battery disconnection is not a repair.
Run the manufacturer's applicable verification conditions in a safe workshop or route. Compare the original operating state with current data for the parking-assist module A messages, and check current and pending faults in related modules. A clean start or idle period does not prove the repair; use the OEM functional check for the affected system.
Compare the original and final fault status. Record the functional-check result and whether the original event returned.
If U0159 returns, compare its suffix, status, failure order and operating conditions with the saved baseline before replacing another part. Revisit the failed branch and inspect anything disturbed. Confirm the prescribed affected-system functional verification separately from code clearing.
Verification follows the system involved. After saving the original evidence, use the OEM procedure to clear erasable records, complete any required calibration or functional check, and compare the final module status with the original warning and fault conditions.
Related Parking-Assist Module A Messages Code Guides
Compare the related monitor families below. Shared symptoms or components do not make their repair procedures interchangeable.
U0159 Frequently Asked Questions
Does the U0159 code mean the named component is bad?
No. U0159 describes lost communication with parking assist control module a, not a confirmed part. It also does not prove that a bumper sensor or the parking controller is necessarily defective. Use the OEM test sequence to distinguish the circuit, load and controller before replacing parts.
What should I check first for U0159?
Save every module's codes and freeze frame before clearing. Confirm the full definition, suffix and VIN architecture. Then inspect recent bumper, trailer-accessory or parking-system work, connectors and shared supplies. Those facts determine whether the next test needs the OEM wiring diagram, approved terminal tools and any prescribed network test equipment or a manufacturer-specific functional procedure.
Can I drive with the U0159 code?
The code does not establish a safe driving distance. Follow the owner manual and actual warning state. Avoid relying on an unavailable assistance or warning function. Stop safely and arrange qualified inspection or towing when braking, steering, essential warnings or other safety functions are abnormal.
Why did U0159 return after a part was replaced?
A replacement can leave U0159 unresolved when the power, connection, topology or configuration prerequisite was never proven. Compare the returning module and status with the original scan rather than treating any warning as the same event.
What should a U0159 repair estimate include?
Ask for the failed-test evidence and a VIN-specific breakdown of diagnosis, parts, labor, taxes, required setup and verification. A code alone cannot establish the repair price.
Can CR Ultra P diagnose and clear U0159?
On a supported vehicle, CR Ultra P can organize available faults, freeze frame, live data and reports, and can clear erasable records after repair. Confirm exact ECU coverage. It cannot replace the OEM functional procedure or physical measurements for the parking-assist module A messages.
The iCarsoft Official Store Technical Team maintains the store's fault-code library. This guide organizes published technical references and verified product information; it does not document a hands-on test of a particular vehicle or claim an individual engineer's review.
Technical and cost references
- Snap-on diagnostic trouble-code catalog. Current visible generic labels only; exact OEM wording, module and suffix control diagnosis.
- Autel DTC reference. Reference labels for U0157 through U0162; not OEM wiring, thresholds or repair instructions.
- GM PIP5094: Prior To Any Circuit Testing. February 2013, 2014 and prior GM cars/light trucks. Connector terminal fit guidance only; the keyword list is not a code-specific diagnosis.
Product information: Official iCarsoft CR Ultra P page.
Editorial note: General diagnostic education, not a substitute for the owner's manual, current VIN-specific service information or professional inspection. Test limits, procedures, coverage and costs vary. Related articles provide context; apply only the specifications and repair procedures that match the vehicle. No universal failure rate, repair price or outcome is implied.
