DTC P1582/17990: Idle Adaptation At Limit
NOTE:
DTC can be caused crankcase oil dilution. An engine oil change is recommended to remedy this condition.
NOTE:
DTC sets when idle adaptation achieves it's limit for at least 5 seconds.
- Inspect throttle valve control module: Disconnect throttle valve control module 8-pin connector. Measure voltage between terminals 3 and 7 of throttle valve control module connector (polarity not specified by manufacturer). See Fig 1 . Turn ignition ON. Battery voltage should be present. Measure voltage between terminals 4 and 7 of throttle valve control module connector. Voltage should be 4-6 Volts. If either voltage is not as specified, repair open in power or ground. If both voltages are as specified, go to next step.
- Connect breakout box (VAG 1598/18) to PCM harness. Measure resistance between throttle valve control module connector terminal 3 and breakout box terminal 10. Measure resistance between throttle valve control module connector terminal 4 and breakout box terminal 41. Measure resistance between throttle valve control module connector terminal 7 and breakout box terminal 33. Resistance should be 1.5 Ohms or less. If resistance is as specified, go to next step. If resistance is not as specified, repair appropriate wire between PCM and throttle valve control module.
- Check for short in harness: Measure resistance between throttle valve control module connector terminal 7 and breakout box terminal 10. Measure resistance between throttle valve control module connector terminal 7 and breakout box terminal 41. Measure resistance between throttle valve control module connector terminal 4 and breakout box terminal 33. Resistance should be infinite. If resistance is as specified, go to next step. If resistance is not as specified, repair appropriate short between PCM and throttle valve control module.
- If all voltage and resistance specifications are okay, inspect exhaust system for leaks. If okay, connect scan tool (VAG 1551/1552) with adapter (VAG 1551/3). Start engine and allow it to idle at closed throttle position. With scan tool in READ MEASURING VALVE BLOCK function, select function 08 and press "Q" button to confirm input. Note Oxygen Sensor (O2S) control in display field No. 3. Spray air intake system with Leak Detector Spray (G 001 800 A1). Air intake leaks will draw in leak detecting spray. The spray reduces air/fuel mixture ignition and engine RPM, and decreases CO reading. Repair leaks as necessary, and go to next step.
- Verify fuel pump and regulator operation. To relieve fuel pressure, wrap a cloth around fitting to be disconnected, and slowly open fitting. On 2.0L, disconnect fuel supply line connection at fuel rail. Connect fuel pressure tester (VAG 1318) using adapters (1318/11 and 1318/16). On 2.8L, connect pressure tester (VAG 1318) with adapter (1318/10) and hose (1318/1), with gauge valve closed. Start engine and check fuel pressure at idle speed. Gauge should read 36 PSI. If pressure is not as specified, replace pump or repair restriction in fuel line. If pressure is as specified, go to next step.
- Disconnect regulator vacuum hose and observe fuel pressure. Pressure should rise to 43 PSI. Switch ignition off and observe residual pressure after 10 minutes. Gauge should read 29 PSI or more. If pressure is okay, go to next step. If pressure drops below specifications, start and run engine. Stop engine and clamp off return line with blue arrow on fuel rail (2.8L), or close pressure gauge handle (2.0L), and observe drop in pressure after 10 minutes. If pressure drops again, inspect fuel pump check valve (all), and inspect hoses, O-rings and injectors for leaks (2.8L). On 2.0L, use scan tool (VAG 1551), in Output Diagnostic Test Mode, with adapter (1551/3) and test box (1598/18) to activate EVAP canister purge regulator and solenoid. Repair as necessary.
- After repairing malfunction(s) and changing engine oil, disconnect ECM connector for 10 seconds to clear DTC. See CLEARING DTCS under INTRODUCTION. If idle adaptation is still exceeded, check for worn fuel injectors and replace as necessary. If problem is still present, check compression pressures. See SPECIFICATIONS article in ENGINE PERFORMANCE. If compression is okay, replace throttle valve control module.