Section 67.2
Troubleshooting Flash Code 71, SID 1/2/3/4/5/6/FMI 0
This diagnostic condition is typically:
- Aerated fuel system
- High system battery (+) supply voltage
- Mechanical injector failure
- Failed solenoid
Note: The injector diagnostic SID indicates which cylinder number has an injector with a short response time. The injector number describes the cylinder and bank that has the injector with a short response time. The diagnostic tool will display the injector text description.
Injector response times generally increase with low battery supply voltage and decrease with high battery supply voltage. Although injector response times vary from injector to injector at a given rpm, each individual injector response time should remain relatively consistent from one firing to the next. Wide variations in response time (typically ± 0.2 ms) for one injector at a steady engine rpm may indicate an electrical problem (faulty alternator or regulator, poor or broken ground cables, etc.). See Figure "N3 Injector" for injector diagram.
Section 67.2.1
Determine Cylinders With Fault
The injector location that is logging the codes is listed in Table "Determine Cylinders With Fault" .
|
SID 1 |
SID 2 |
SID 3 |
SID 4 |
SID 5 |
SID 6 |
Firing Order |
# 1 |
# 2 |
# 3 |
# 4 |
# 5 |
# 6 |
S60 Cylinder # (block location) |
1 |
5 |
3 |
6 |
2 |
4 |
- Disconnect the 10-pin injector harness connector.
- Establish a good ECM/ECU case ground by measuring the resistance across two points on the ECM/ECU. The resistance should measure less than or equal to 1 Ω.
- Once a good case ground is established, keep one of the measurement probes in place and move the other probe to one of the exposed male injector terminals on the ECM/ECU.
- Measure the resistance. Repeat this procedure at each of the terminals.
- If any terminals have a resistance of less than 1000 Ω, replace the ECM/ECU. Refer to "67.2.4.1 Verify Repairs" .
- If all terminals have a resistance of greater than 1000 Ω, refer to "67.2.2 Check for Short" .
Section 67.2.2
Check for Short
Perform the following steps to check for a short. See Figure "Injector Harness" .

Figure 1. Injector Harness
- Locate the injector harness connector terminals associated with the codes.
- Measure resistance between those cavities and the cylinder block.
- Also, measure resistance between that cavity and the appropriate return cavity (G or E).
- If measured resistance is less than 5 Ω, the wire is shorted. Repair or replace the harness and refer to "67.2.4.1 Verify Repairs" .
- If measured resistance is greater than 5 Ω, refer to "67.2.3 Check for Open" .
Section 67.2.3
Check for Open
Perform the following steps to check for an open.
- Insert a jumper wire between the cavity associated with the code and the return for that connector (E-61 and E-62).
- Remove the valve cover to gain access to the cylinder associated with the code.
- Remove the connector terminals at the injector solenoid.
- Measure resistance between the terminal plugs.
- If the measured resistance is greater than 5 Ω, the injector wire is open. Repair or replace the harness and refer to "67.2.4.1 Verify Repairs" .
- If the measured resistance is less than 5 Ω, and the ECM/ECU software is less than 3.00, reprogram the ECM/ECU. Refer to "67.2.4.1 Verify Repairs" .
- If the measured resistance is less than 5 Ω, and the ECM/ECU software is 3.00 or higher, remove the alternator belt to disable the alternator and refer to "67.2.4 Assemble" .
Section 67.2.4
Assemble
Perform the following steps to assemble the components.
- Connect the connectors.
- Install the valve cover.
- Start and run the engine.
- Stop engine.
- Does the code return?
- If the code does not return, repair or replace the alternator grounds and refer to "67.2.4.1 Verify Repairs" .
- If the codes return, replace the injector and solenoid. Refer to "67.2.4.1 Verify Repairs" .
Section 67.2.4.1
Verify Repairs
Perform the following steps to verify repairs:
- Start and run the engine.
- Stop engine.
- Check diagnostic tool for codes.
- If no codes are logged, no further troubleshooting is required.
- If injector codes are logged, all system diagnostics are complete. Please review this section from the first step to find the error. Refer to "67.2.1 Determine Cylinders With Fault" .
Series 60 DDEC V Troubleshooting Guide - 6SE570 |
Generated on 10-13-2008 |