Austin A135 P1642 Engine Trouble Code
What is Austin A135 P1642?
Austin A135 P1642 indicates potential catalytic converter failure. If completely failed, your vehicle may not run properly and fuel economy will suffer significantly. Average replacement cost is $2,000–$2,140. This repair requires professional service and should not be delayed.
P1642 on the Austin A135
The Austin A135 ECU flash version prior to the 2.4.1 update has a known calibration bug that can generate spurious P1642 codes under hard deceleration. Verifying the ECU software version is always the first step before any mechanical diagnosis on this model.
Code Information
| Code Type: | OBD-II Powertrain (P) Trouble Code |
| System: | Powertrain |
| Vehicle: | Austin A135 |
| Brand: | Austin |
| Model: | A135 |
| Code: | P1642 |
P1642 Austin A135 Symptoms
Check Engine Light
Illuminated Austin A135 dashboard warning
Engine Stalling
Engine stops unexpectedly or misfires
Performance Issues
Reduced power or acceleration on the Austin A135
Starting Problems
Difficulty starting the engine
Poor Fuel Economy
Increased fuel consumption on the Austin A135
Increased Emissions
Failed emissions test due to P1642
P1642 Code Structure
Understanding what each digit means in the P1642 powertrain trouble code:
| P | 1 | 6 | 4 | 2 |
|---|---|---|---|---|
| Powertrain Code | Fuel And Air Metering | Fuel Temperature Sensor B Circuit Range/Performance | Injection Pump Fuel Metering Control 'B' High | Glow Plug/Heater Circuit 'A' Malfunction |
How to Fix Austin A135 P1642
Diagnostic Steps:
The catalytic converter has oxygen sensors before and after it. When warm and in closed-loop mode, the upstream O2 sensor reading should fluctuate, while downstream should remain steady.
Repair Solution:
Gasoline engines use spark plugs to ignite fuel-air mixture. Proper timing ensures the explosion occurs when the piston is positioned correctly. Incorrect plug wire sequencing causes mistimed ignition, resulting in poor performance.
Technical Notes:
P1642 DTC specifically relates to camshaft timing. When cam timing is over-retarded, the check-engine light illuminates and this code sets. Verify VCT solenoid operation and check for contamination.
Austin A135 P1642 Repair Cost
Addressing P1642 on your Austin A135 typically involves: dealer diagnostic fee $95–$150, oxygen sensor replacement $180–$320 (parts + labour), or catalytic converter replacement $1,800–$2,400 if damage has progressed. Independent specialist garages often charge 20–30% less than franchised dealers for identical work.
P1642 Description
P1642 engine trouble code is related to Glow Plug/Heater Circuit 'A' Malfunction.
Main Cause
The primary reason for P1642 OBD-II Engine Trouble Code is: Fuel Temperature Sensor B Circuit Range/Performance.
Common P1642 Misdiagnosis on the Austin A135
Workshop technicians sometimes replace the entire ignition coil assembly on the Austin A135 when P1642 accompanies a cylinder-specific misfire. In many cases, only the spark plug in the misfiring cylinder has fouled; a $8 plug replaces a $140 coil pack.
DIY Repair Guide: P1642 on Austin A135
For the mechanically confident Austin A135 owner, a DIY MAF sensor clean is a rewarding first step for P1642. Use a dedicated MAF sensor cleaner spray — not brake cleaner, which damages the sensing element — and allow the sensor to dry for 30 minutes before reinstallation.
Preventing P1642 on the Austin A135
Using only genuine or OEM-specification fuel injectors in the Austin A135 ensures precise spray pattern and flow rate. Inferior aftermarket injectors are a documented trigger for P1642 through off-target fuel delivery.
Frequently Asked Questions — Austin A135 P1642
A: Yes. Any stored fault code — including P1642 — will cause an automatic failure in most OBD-II based emissions tests. The code must be resolved and the vehicle must complete a full OBD drive cycle with no new codes before the test.