MBE 900 4000 Troubleshooting – Section 6.2 Troubleshooting PID 91

Section 6.2
Troubleshooting PID 91

The following procedure will troubleshoot PID 91.‪

Section 6.2.1
091 02 – Position Active Fault (Erratic Data)

Perform the following steps to troubleshoot a position active fault.‪

1. Check for active codes.
   1. If fault code 091 04 was active, refer to "6.2.3 091 04 – Voltage Low" .
   2. If fault code 091 03 was active, refer to "6.2.2 091 03 – Voltage High" .
   3. If no other fault codes were active, go to step 2 .
2. Measure the power supply voltage to the AP assembly.
   1. If the voltage measured was not within the range of 4.8 – 5.2 V, go to step 3 .
   2. If the voltage measured was within the range of 4.8 – 5.2 V, refer to "6.2.1.1 Required Actions" .
3. Unplug the AP connector from the foot pedal and measure the power supply voltage.
   1. If the power voltage was not within 4.8 – 5.2 V, go to step 5 .
   2. If the power voltage was within 4.8 – 5.2 V, refer to "6.2.1.2 Required Actions" .
4. Reconnect the AP connector.
5. Measure the power supply voltage to the AP assembly with wires 440P+ (pin 9 of the 21-pin connector) and 440P- (pin 14 of the 21-pin connector) disconnected. See Figure "Accelerator Pedal to DDEC-VCU Connectors" .
   1. If the power voltage was not within 4.8 – 5.2 V, contact the Detroit Diesel Technical Service Group.
   2. If the power voltage was within 4.8 – 5.2 V, refer to "6.2.1.3 Required Actions" .

Section 6.2.1.1
Required Actions

Perform the following step to resolve a position active fault.‪

1. Repair or replace wires 440T, 440P+, and 440P- (pins 11, 9, and 14 of the 21-pin connector) as necessary.

Section 6.2.1.2
Required Actions

Perform the following steps to resolve a position active fault.‪

1. Replace the AP assembly.
2. Erase the fault code memory.

Section 6.2.1.3
Required Actions

Perform the following steps to resolve a position active fault.‪

1. Repair or replace wires 440P+ and 440P- (pins 9 and 14 of the 21-pin connector).
2. Replace the DDEC-VCU, if necessary.
3. Erase the fault code memory.

Section 6.2.2
091 03 – Voltage High

Perform the following steps to troubleshoot voltage high.‪

1. Check for continuity between wires 440P+ and 440T with the 21-pin connector disconnected. See Figure "Accelerator Pedal to DDEC-VCU Connectors" .
   1. If continuity was not measured, go to step 2 .
   2. If continuity was measured, refer to "6.2.2.1 Required Actions" .
2. Check for continuity in wire 440P- between pin 14 of the 21-pin connector and the AP sensor connector pin B.
   1. If continuity was measured, go to step 3 .
   2. If continuity was not measured, refer to "6.2.2.2 Required Actions" .
3. Check for continuity in wire 440T between the AP sensor connector pin A and pin 11 of the 21-pin connector.
   1. If continuity was measured, refer to "6.2.2.4 Required Actions" .
   2. If continuity was not measured, refer to "6.2.2.3 Required Actions" .

Section 6.2.2.1
Required Actions

Perform the following steps to resolve voltage high.‪

1. Repair the short circuit between wires 440P+ and 440T connecting the DDEC-VCU to the AP sensor.
2. Erase the fault code memory.

Section 6.2.2.2
Required Actions

Perform the following steps to resolve voltage high.‪

1. Repair the open circuit in wire 440P- connecting the DDEC-VCU to the AP connector.
2. Erase the fault code memory.

Section 6.2.2.3
Required Actions

Perform the following steps to resolve voltage high.‪

1. Repair the open circuit in wire 440T connecting the DDEC-VCU to the AP connector.
2. Erase the fault code memory.

Section 6.2.2.4
Required Actions

Perform the following steps to resolve voltage high.‪

1. Replace the AP assembly.
2. Erase the fault code memory.

Section 6.2.3
091 04 – Voltage Low

Perform the following steps to troubleshoot voltage low.‪

1. Measure for a short to ground from wire 440T at the AP connector.
   1. If a short to ground was not measured, go to step 2 .
   2. If a short to ground was measured, refer to "6.2.3.1 Required Actions" .
2. Check for continuity in wire 440P+.
   1. If continuity was not measured, refer to "6.2.3.2 Required Actions" .
   2. If continuity was measured, refer to "6.2.3.3 Required Actions" .

Section 6.2.3.1
Required Actions

Perform the following steps to resolve voltage low.‪

1. Repair the short to ground in wire 440T.
2. Erase the fault code memory.

Section 6.2.3.2
Required Actions

Perform the following steps to resolve voltage low.‪

1. Repair the open circuit in wire 440P+.
2. Erase the fault code memory.

Section 6.2.3.3
Required Actions

Perform the following steps to resolve voltage low.‪

1. Replace the AP assembly.
2. Erase the fault code memory.