OBD Guide

U1135

Invalid Or Missing Data For Ignition Switch / Starter

U1135 is an OBD-II diagnostic trouble code meaning: Invalid Or Missing Data For Ignition Switch / Starter. Common causes: ignition switch malfunction, problems with wiring or connectors. Estimated repair cost: $17–111.

Severity
⚠️ Medium
Can you drive?
Do not drive — repair immediately
Approx. repair cost
$17–111 (est.)

Symptoms

  • Difficulty starting the engine
  • Floating idle speed
  • Check Engine Light Is On
  • Lost connection with diagnostic equipment

Causes

  • Ignition switch malfunction
  • Problems with wiring or connectors
  • CAN bus malfunctions
  • Engine control module (ECU) malfunction
  • Software error in one of the control units

How to Fix

  1. Check the condition of the ignition switch
  2. Diagnose the state of the CAN bus
  3. Inspect the connectors and wiring of the ignition system
  4. Scan all modules for errors
  5. If necessary, reflash or replace the control unit

Related codes

FAQ

What does the U1135 code mean?

U1135 is an OBD-II diagnostic trouble code that indicates: Invalid Or Missing Data For Ignition Switch / Starter

What causes a U1135 error code?

The most common causes of U1135 include: Ignition switch malfunction; Problems with wiring or connectors; CAN bus malfunctions; Engine control module (ECU) malfunction.

How do I fix a U1135 diagnostic trouble code?

To fix U1135: Check the condition of the ignition switch. Diagnose the state of the CAN bus. Inspect the connectors and wiring of the ignition system. For a complete diagnosis, use an OBD-II scanner.

Is it safe to drive with U1135?

Do not drive — repair immediately

How much does it cost to fix U1135?

The estimated repair cost for U1135 is $17–111. Actual cost depends on your vehicle, location, and labor rates.

See also: Russian version · NationStat