1999 Audi A4 Coding

P0102(1) (1) 16486MAF Circuit Low Input
P1338(1) (1) 17746Camshaft Position Sensor Open Circuit Or Short To B+
P1602(4) (4) 18010Power Supply (B+) Terminal 30 Low Voltage

(1)MIL is switched on after 2 trips
(4)MIL is not switched on.

DTC P0102/16486 & P0103/16487: MAF CIRCUIT FAILURE
Inspect Mass Airflow (MAF) sensor connector for looseness and/or corrosion. Repair sensor connector as necessary. If sensor connector was okay, go to next step. If sensor connector was repaired, erase DTC memory. See CLEARING CODES in SELF-DIAGNOSTICS - INTRODUCTION article.
Check MAF sensor fuse. Replace if necessary. Turn off all electrical accessories. Engine coolant fan must not run during test. Turn ignition off. Disconnect MAF sensor connector. Turn ignition on. Using a DVOM, check voltage between MAF sensor connector terminals No. 1 and 3. Voltage should be 9-14.5 volts. If voltage is within specification, go to step 4. If voltage is not within specification, go to next step.
Repair open wiring between MAF sensor and PCM as necessary.

DTC P1337/17745 & P1338/17746: CAMSHAFT POSITION SENSOR FAILURE
Inspect Camshaft Position (CMP) sensor connector for looseness and/or corrosion. CMP sensor is located at front driver side of engine. Repair sensor connector as necessary. If sensor connector was not repaired, go to next step. If sensor connector was repaired, erase DTC memory. See CLEARING CODES in SELF-DIAGNOSTICS - INTRODUCTION article.
Turn ignition off. Disconnect Camshaft Position (CMP) sensor 3-pin connector. Turn ignition on. Connect a DVOM between CMP sensor connector (harness side) terminals No. 1 and 3.
Voltage should be 9-14.5 volts. If voltage is within specification, go to next step. If voltage is not to specification, repair wiring harness between CMP sensor connector and Powertrain Control Module (PCM). See WIRING DIAGRAMS article. Erase DTC memory. See CLEARING CODES in SELF-DIAGNOSTICS - INTRODUCTION article.
Turn ignition off. Connect VAG 1598/22 test box to PCM harness connector. Using a DVOM, measure resistance between CMP sensor connector (harness side) and the following terminals:
CMP sensor connector (harness side) terminal No. 1 and test box socket 11.
CMP sensor connector (harness side) terminal No. 2 and test box socket 76.
CMP sensor connector (harness side) terminal No. 3 and test box socket 67.
Resistance specification is 1.5 ohms or less. If resistance is within specification, go to next step. If resistance is not within specification, repair open in wiring harness as necessary. See WIRING DIAGRAMS article. Erase DTC memory. See CLEARING CODES in SELF-DIAGNOSTICS - INTRODUCTION article.
Using a DVOM, measure resistance between CMP sensor connector (harness side) and the following terminals:
CMP sensor connector (harness side) terminal No. 2 and test box socket 11.
CMP sensor connector (harness side) terminal No. 3 and test box socket 11.
CMP sensor connector (harness side) terminal No. 3 and test box socket 76.
Resistance specification is infinity. If resistance is infinity, go to next step. If resistance is not infinity, repair short in wiring harness as necessary. See WIRING DIAGRAMS article. Erase DTC memory. See CLEARING CODES in SELF-DIAGNOSTICS - INTRODUCTION article.
If wiring is okay and voltage between CMP connector (harness side) terminals No. 1 and 3 is okay, replace CMP sensor. Erase DTC memory. See CLEARING CODES in SELF-DIAGNOSTICS - INTRODUCTION article.
If wiring is okay, but there is no voltage between CMP connector (harness side) terminals No. 1 and 3, replace PCM. See PCM REPLACEMENT in SELF-DIAGNOSTICS - INTRODUCTION article.

DTC P1602/18010: PCM LOW VOLTAGE
Turn ignition off. Disconnect Powertrain Control Module (PCM) connectors. Connect VAG 1598/22 test box to PCM wiring harness. Using DVOM, check voltage between test box sockets No. 2 and 3, then 1 and 3.
Voltage should be 10-14.5 volts for each reading. If voltage is within specification, erase DTC memory. See CLEARING CODES in SELF-DIAGNOSTICS - INTRODUCTION article. If voltage is not within specification, repair wiring harness as necessary. Erase DTC memory. See CLEARING CODES in SELF-DIAGNOSTICS - INTRODUCTION article.